Dichloropropene, 1,3- Dichlopropane and Mixtures, 1,2- (EHC 146, 1993)

INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY

ENVIRONMENTAL HEALTH CRITERIA 146

1,3-Dichloropropene, 1,2-Dichloropropane
and Mixtures

This report contains the collective views of an international group of
experts and does not necessarily represent the decisions or the stated
policy of the United Nations Environment Programme, the International
Labour Organisation, or the World Health Organization.

Published under the joint sponsorship of
the United Nations Environment Programme,
the International Labour Organisation,
and the World Health Organization

World Health Orgnization
Geneva, 1993

The International Programme on Chemical Safety (IPCS) is a joint
venture of the United Nations Environment Programme, the International
Labour Organisation, and the World Health Organization. The main
objective of the IPCS is to carry out and disseminate evaluations of
the effects of chemicals on human health and the quality of the
environment. Supporting activities include the development of
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that could produce internationally comparable results, and the
development of manpower in the field of toxicology. Other activities
carried out by the IPCS include the development of know-how for coping
with chemical accidents, coordination of laboratory testing and
epidemiological studies, and promotion of research on the mechanisms
of the biological action of chemicals.

WHO Library Cataloguing in Publication Data

1,3-Dichloropropene, 1,2-dichloropropane and mixtures.

(Environmental health criteria: 146)

1. Environmental exposure 2. Hydrocarbons, Chlorinated - adverse
effects 3. Hydrocarbons, Chlorinated - poisoning 4. Hydrocarbons,
Chlorinated - toxicity 5. Occupational exposure I.Series

ISBN 92 4 157146 2 (NLM Classification QV 633)
ISSN 0250-8634

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CONTENTS

ENVIRONMENTAL HEALTH CRITERIA FOR 1,3-DICHLOROPROPENE,
1,2-DICHLOROPROPANE, AND MIXTURES

PART A. 1,3-DICHLOROPROPENE

PART B. 1,2-DICHLOROPROPANE

PART C. MIXTURES OF DICHLOROPROPENES AND DICHLOROPROPANE

REFERENCES

RESUME ET EVALUATION, CONCLUSIONS, ET RECOMMANDATIONS

RESUMEN Y EVALUACION, CONCLUSIONES, Y RECOMENDACIONES

WHO TASK GROUP ON ENVIRONMENTAL HEALTH
CRITERIA FOR 1,3-DICHLOROPROPENE,
1,2-DICHLOROPROPANE, AND MIXTURES

Members

Dr V. Benes, Department of Toxicology and Reference Laboratory,
Institute of Hygiene & Epidemiology, Prague, Czechoslovakia

Dr R. Drew, Key Centre for Toxicology, Department of Applied
Biology, Royal Melbourne Institute for Technology, Melbourne,
Victoria, Australia (Chairman)

Dr S.K. Kashyap, National Institute of Occupational Health,
Ahmedabad, India

Dr J.I. Kundiev, Research Institute of Labour Hygiene & Occupational
Diseases, Kiev, Ukraine (Vice-Chairman)

Dr K. Mitsumori, Division of Pathology, Biological Safety Research
Center, National Institute of Hygienic Sciences, Tokyo, Japan

Dr Richard F. Shore, Ecotoxicology and Pollution Section, Institute
of Terrestrial Ecology, Monks Wood Experimental Station, Abbots
Ripton, Huntingdon, United Kingdom

Dr G.J. van Esch, Oranje, Bilthoven, Netherlands (Rapporteur)

Dr E.A.H. van Heemstra-Lequin, Laren, Netherlands (Joint
Rapporteur)

Dr S. Wong, Bureau of Chemical Hazards, Environmental Health
Directorate, Department of National Health and Welfare,
Tunney's Pasture, Ottawa, Ontario, Canada

Observers

Dr D.E. Owen, Shell Internationale Petroleum Maatschappij BV, The
Hague, Netherlands

Members from the Host Institution

Dr W.H. Gross, Fraunhofer Institute of Toxicology & Aerosol
Research, Hanover, Germany

Dr J.R. Kielhorn, Fraunhofer Institute of Toxicology & Aerosol
Research, Hanover, Germany

Dr C.M. Melber, Fraunhofer Institute of Toxicology & Aerosol
Research, Hanover, Germany

Secretariat

Dr R.F. Hertel, Fraunhofer Institute of Toxicology & Aerosol
Research, Hanover, Germany

Dr K.W. Jager, International Programme on Chemical Safety, World
Health Organization, Geneva, Switzerland (Secretary)

Mme C. Partensky, Unit of Carcinogen Identification and Evaluation,
International Agency for Research on Cancer (IARC), Lyon,
France

NOTE TO READERS OF THE CRITERIA MONOGRAPHS

Every effort has been made to present information in the
criteria monographs as accurately as possible without unduly
delaying their publication. In the interest of all users of the
Environmental Health Criteria monographs, readers are kindly
requested to communicate any errors that may have occurred to the
Director of the International Programme on Chemical Safety, World
Health Organization, Geneva, Switzerland, in order that they may be
included in corrigenda.

* * *

A detailed data profile and a legal file can be obtained from
the International Register of Potentially Toxic Chemicals, Palais
des Nations, 1211 Geneva 10, Switzerland (Telephone No. 7988400 or
7985850).

* * *

Note: The proprietary information contained in this monograph
cannot replace documentation for registration purposes, because the
latter has to be closely linked to the source, the manufacturing
route, and the purity/impurities of the substance to be registered.
The data should be used in accordance with paragraphs 82-84 and
recommendations paragraph 90 of the Second FAO Government
Consultation (1982).

ENVIRONMENTAL HEALTH CRITERIA FOR
1,3-DICHLOROPROPENE, 1,2-DICHLOROPROPANE, AND MIXTURES

The meeting of the WHO Task Group on Environmental Health
Criteria for 1,3-dichloropropene, 1,2-dichloropropane, and mixtures,
which was held at the Fraunhofer Institute of Toxicology and Aerosol
Research, Hanover, Germany, from 16 to 20 September 1990, was
sponsored by the German Ministry of the Environment. Dr R.F. Hertel
welcomed the participants on behalf of the host institute. Dr K.W.
Jager, IPCS, welcomed the participants on behalf of Dr M. Mercier,
Director of the IPCS, and the three IPCS cooperating organizations
(UNEP/ILO/WHO). The Group reviewed and revised the draft criteria
monograph and made an evaluation of the risks for human health and
the environment from exposure to 1,3-dichloropropene, 1,2-
dichloropropane, and mixtures of dichloropropenes and
dichloropropane.

Dr E.A.H. van Heemstra-Lequin and Dr G.J. van Esch of the
Netherlands cooperated in the preparation of the first draft of the
EHC monograph. Dr van Esch prepared the second draft, incorporating
the comments received following circulation of the first draft to
the IPCS contact points for Environmental Health Criteria
monographs.

Dr K.W. Jager of the IPCS Central Unit was responsible for the
scientific content of the monographs, and Mrs M.O. Head of Oxford
for the editing.

The fact that Shell and Dow Chemical made their proprietary
toxicological information on their products available to the IPCS
and the Task Group is gratefully acknowledged. This allowed the Task
Group to make their evaluation on a more complete data base.

The efforts of all who helped in the preparation and
finalization of the publications are gratefully acknowledged.

* * *

Partial financial support for the publication of this criteria
monograph was kindly provided by the United States Department of
Health and Human Services, through a contract from the National
Institute of Environmental Health Sciences, Research Triangle Park,
North Carolina, USA - a WHO Collaborating Centre for Environmental
Health Effects.

PART A

ENVIRONMENTAL HEALTH CRITERIA FOR 1,3-DICHLOROPROPENE

CONTENTS

ENVIRONMENTAL HEALTH CRITERIA FOR 1,3-DICHLOROPROPENE

1. SUMMARY AND EVALUATION, CONCLUSIONS, AND RECOMMENDATIONS

1.1 Summary and evaluation
1.1.1 Use, environmental fate, and environmental levels
1.1.2 Kinetics and metabolism
1.1.3 Effects on organisms in the environment
1.1.4 Effects on experimental animals and in vitro
test systems
1.1.5 Effects on human beings
1.2 Conclusions
1.3 Recommendations

2. IDENTITY, PHYSICAL AND CHEMICAL PROPERTIES, ANALYTICAL METHODS

2.1 Identity
2.2 Physical and chemical properties
2.3 Conversion factors
2.4 Analytical methods
2.4.1 Sampling
2.4.2 Determination of residues in crops and soil
2.4.3 Determination of residues in water
2.4.4 Determination of residues in air
2.4.5 Determination of residues in food
2.4.6 Determination of 3-chloroallyl alcohol
2.4.7 Determination of mercapturic acids in urine

3. SOURCES OF HUMAN AND ENVIRONMENTAL EXPOSURE

3.1 Natural occurrence
3.2 Man-made sources
3.2.1 Production levels and processes
3.2.2 Use
3.2.3 Sources of pollution

4. ENVIRONMENTAL TRANSPORT, DISTRIBUTION, AND TRANSFORMATION

4.1 Transport and distribution between media
4.1.1 Air
4.1.2 Water
4.1.3 Soil
4.1.3.1 Hydrolysis
4.1.3.2 Volatilization
4.1.3.3 Uptake in crops
4.1.3.4 Movement in soil
4.1.3.5 Loss under field conditions
4.1.3.6 Results of supervised field trials
4.2 Bioconcentration

4.3 Abiotic degradation
4.3.1 Photodegradation
4.4 Biodegradation and biotransformation
4.4.1 Miscellaneous

5. ENVIRONMENTAL LEVELS AND HUMAN EXPOSURE

5.1 Air
5.2 Water
5.3 Crops
5.4 Occupational exposure

6. KINETICS AND METABOLISM

6.1 Absorption, distribution, and elimination
6.1.1 Oral
6.1.1.1 Rat
6.1.1.2 Mouse
6.1.2 Inhalation
6.1.2.1 Rat
6.2 Influence on tissue levels of glutathione
6.2.1 Oral
6.2.2 Inhalation
6.3 Biotransformation
6.3.1 Rat
6.3.2 Humans
6.4 Reaction with macromolecules
6.4.1 Mouse
6.4.2 Rat
6.5 Appraisal

7. EFFECTS ON ORGANISMS IN THE ENVIRONMENT

7.1 Acute toxicity
7.1.1 Microorganisms
7.1.2 Algae
7.1.3 Invertebrates
7.1.4 Honey bees
7.1.5 Fish
7.1.6 Birds
7.2 Short-term/long-term toxicity
7.2.1 Invertebrates
7.2.2 Fish
7.2.3 Field studies
7.2.4 Phytotoxicity

8. EFFECTS ON EXPERIMENTAL ANIMALS AND IN VITRO TEST SYSTEMS

8.1 Single exposures
8.1.1 Oral

8.1.2 Inhalation
8.1.3 Dermal
8.2 Short-term exposures
8.2.1 Oral
8.2.2 Inhalation
8.2.2.1 Mouse
8.2.2.2 Rat
8.2.2.3 Other animal species
8.3 Skin and eye irritation, sensitization
8.3.1 Skin irritation
8.3.2 Eye irritation
8.3.2.1 In vitro studies
8.3.3 Sensitization
8.4 Long-term exposure
8.5 Reproduction, embryotoxicity, and teratogenicity
8.5.1 Reproduction
8.5.1.1 Inhalation (rat)
8.5.1.2 Intraperitoneal (mouse)
8.5.2 Teratogenicity
8.5.2.1 Inhalation (rat)
8.5.2.2 Inhalation (rabbit)
8.6 Mutagenicity and related end-points
8.6.1 In vitro studies
8.6.1.1 Microorganisms
8.6.1.2 Effects of glutathione on bacterial
mutagenesis
8.6.1.3 Mammalian cells
8.6.1.4 DNA damage
8.6.1.5 Chromosomal effects
8.6.2 In vivo studies
8.6.3 Appraisal
8.7 Carcinogenicity
8.7.1 Oral
8.7.1.1 Mouse
8.7.1.2 Rat
8.7.2 Inhalation
8.7.2.1 Mouse
8.7.2.2 Rat
8.7.3 Appraisal
8.7.4 Dermal and subcutaneous (mouse)
8.8 Factors modifying toxicity, toxicity of metabolites, mode
of action
8.8.1 Toxicity of metabolites, cis- and trans-
1,3-dichloropropene oxide
8.8.1.1 Mutagenicity
8.8.1.2 Carcinogenicity
8.8.2 Role of oxidation
8.8.3 Role of glutathione
8.8.4 Effect on liver enzyme activity

9. EFFECTS ON HUMANS

9.1 General population
9.1.1 Acute toxicity - poisoning incidents
9.1.2 Controlled human studies
9.2 Occupational exposure
9.2.1 General
9.2.2 Acute toxicity - poisoning incidents
9.2.3 Effects of short- and long-term exposure

10. PREVIOUS EVALUATIONS BY INTERNATIONAL BODIES

1. SUMMARY AND EVALUATION, CONCLUSIONS, AND RECOMMENDATIONS

1.1 Summary and evaluation

1.1.1 Use, environmental fate, and environmental levels

"1,3-Dichloropropene" was introduced in 1956 as part of a
mixture, containing 1,3-dichloropropenes, 1,2-dichloropropane, and
other halogenated hydrocarbons, and has been widely used in
agriculture as a pre-plant soil fumigant for the control of
nematodes in vegetables, potatoes, and tobacco. Application is
primarily by soil injection. The commercial formulation of 1,3-
dichloropropene is a mixture of cis- and trans-isomers (in
approximately equal proportions), which is a colourless to amber
liquid with a penetrating, irritating, chloroform-like odour. The
vapour pressure is 3.7 kPa at 20 °C. The technical product has a
purity of 92% and may contain a number of impurities, such as 1,2-
dichloropropane. The log P octanol/water partition coefficient is
1.98.

In air, decomposition of 1,3-dichloropropene is mainly by
reaction with free radicals and ozone. The half-lives of the cis-
and trans-isomers in the reaction with free radicals are 12 and
7 h, respectively, and in the reaction with ozone, 52 and 12 days,
respectively. Direct photo-transformation seems to be insignificant,
but may be enhanced in the presence of atmospheric particles.

In water, 1,3-dichloropropene is likely to disappear rapidly,
because of its relatively low water solubility and high volatility;
half-lives of less than 5 h have been reported.

The distribution of 1,3-dichloropropene in soil compartments is
dependent on the vapour pressure, diffusion coefficient,
temperature, and moisture content of the soil. The persistence of
1,3-dichloropropene in soil is influenced by volatilization,
chemical and biological transformation, photochemical
transformation, and organism uptake. Volatilization and diffusion in
the vapour phase are the most significant mechanisms for
environmental dispersion and dilution.

Transformation of 1,3-dichloropropene is initially by
hydrolysis to 3-chloroallyl alcohol and then by microbial
transformation to 3-chloroacrolein and 3-chloroacrylic acid. In a
laboratory study, the half-lives for the hydrolysis of the cis-
and trans-isomers of 1,3-dichloropropene at 15 °C and 29 °C were
11.0 and 2.0 days, respectively, for the cis-isomer and 13.0 and
2.0 days for the trans-isomer. In soil with a pH of 7 and a
temperature of 25 °C, the half-life for hydrolysis for both isomers
was 4.6 days. Because of its relatively rapid disappearance from
soil, residues are unlikely to accumulate when the fumigant is
applied at the recommended rate and frequency.

1,3-Dichloropropene is potentially mobile in soil, especially
in open-textured, sandy soil with a low moisture content. Downward
movement is enhanced by deep cultivation of soils with low porosity.
1,3-Dichloropropene has been detected in "upper groundwater" (up to
2 m below the surface), but not in deep groundwater, which is more
likely to be used for drinking-water.

1,3-Dichloropropene can be taken up by crops. However,
significant residues are unlikely to occur in edible crops, because
these are not normally planted until most of the fumigant has
dissipated.

Bioaccumulation of 1,3-dichloropropene is unlikely, because of
its relatively high water solubility (> 1 g/kg), low log P octanol
water partition coefficient, and rapid elimination from mammals and
other organisms.

1.1.2 Kinetics and metabolism

1,3-Dichloropropene administered orally to rodents is rapidly
eliminated. The major route of elimination is in the urine where 81%
of the cis-isomer and 56% of the trans-isomer are eliminated
within 24 h of dosing. The half-life of elimination in the urine is
5-6 h. Faecal elimination is minor. Expired carbon dioxide accounts
for 4 and 24% of the elimination of the cis- and trans-isomers
of 1,3-dichloropropene, respectively. Tissue concentrations after
oral administration are low; the highest residual concentrations are
found in the stomach wall, followed by lower amounts in the kidneys,
liver, and bladder.

Unchanged 1,3-dichloropropene is not found in the urine. The
cis- and trans-isomers are substrates for hepatic glutathione-
S-alkyl transferase, forming mercapturic acids, which are excreted
in the urine. The trans-isomer is conjugated 4-5 times more slowly
than the cis-isomer. The principal urinary metabolite in rats and
mice is N-acetyl- S-(3-chloroprop-2-enyl)L-cysteine; this
compound can be used for biological monitoring in humans. A second,
minor metabolic pathway has been identified for the cis-isomer
that involves mono-oxygenation to cis-1,3-dichloropropene oxide,
which can also be conjugated with glutathione. The high proportion
of the trans-isomer that occurs in expired air results from an
alternative metabolic pathway to conjugation that has a higher
specificity for the trans- than for the cis-isomer.

Inhalation exposure of rats to 1,3-dichloropropene did not lead
to increases in blood concentrations proportional with dose. At a
dose of 408.6 mg/m³ (90 ppm), respiratory frequency and
respiratory minute volume were decreased and saturation of
metabolism occurred at 1362 mg/m³ (300 ppm). Cis- and trans-
isomers were rapidly eliminated from the blood, the half-life of

elimination being 3-6 min at concentrations below 1362 mg/m³ but
considerably longer (33-43 min) at higher concentrations.

1.1.3 Effects on organisms in the environment

The EC₅₀ values for growth (96 h) for the freshwater alga,
Selenastrum capricornutum, and the estuarine diatom, Skeletoneria
costatum, are 4.95 mg/litre and 1 mg/litre, respectively. The
acute toxicity (96-h LC₅₀) of 1,3-dichloropropene for fish is of
the order of 1-7.9 mg/litre. In an embryo-larval test on Fathead
minnow, the maximum no-effect level was 0.24 mg/litre. These data
and the fact that 1,3-dichloropropene is unlikely to persist in
water, indicate that the hazard for fish lies in acute toxic
effects, with little potential for additional effects resulting from
long-term exposure.

1,3-dichloropropene at dose levels of 30-60 mg/kg can reduce
the abundance of fungi and the rate of microbial enzyme activity,
but the effect is not usually long lasting (< 7 days) and does not
occur in all soil types. In some studies, there was a significant
increase in microbial numbers following application.

1,3-Dichloropropene is phytotoxic, however, its toxicity for
Honey bees is low. Using a dusting technique, the 48-h LD₅₀ was
6.6 µg/bee. Birds are relatively non-sensitive to 1,3-
dichloropropene. LC₅₀s (8-day) of > 10 g/kg were reported for
Mallard duck and Bobwhite quail.

1.1.4 Effects on experimental animals and in vitro test systems

The acute oral toxicity of 1,3-dichloropropene in animals is
moderate to high. The LD₅₀ values reported in rats ranged between
127 and 713 mg/kg body weight. The oral LD₅₀ values in rats for
the cis- and trans-isomers were 85 and 94 mg/kg body weight,
respectively.

Acute dermal exposure is moderately toxic. Dermal LD₅₀s of
423 mg/kg body weight and 504 mg/kg body weight have been reported
for the rat and the rabbit, respectively. The LD₅₀ values for the
cis- and trans-isomers were 1090 and 1575 mg/kg body weight,
respectively.

Inhalation exposure (4 h) of rats indicated LC₅₀s of 3310
mg/m³ (729 ppm) for 1,3-dichloropropene; 3042-3514 mg/m³ for the
cis-isomer, and 4880-5403 mg/m³ for the trans-isomer.

Acute intoxication showed central nervous and respiratory
system involvement.

Severe reactions were seen in rabbit skin and eye irritation
tests, but recovery occurred in 14-21 days. The results of skin
sensitization tests on guinea-pigs were positive.

Several short-term inhalation toxicity studies have been
conducted on mice, rats, guinea-pigs, rabbits, and dogs. In mice,
the nasal mucosa and urinary bladder were the target organs.
Degeneration of the olfactory epithelium and hyperplasia of the
respiratory epithelium were observed. Moderate hyperplasia of the
transitional epithelium in the urinary bladder was found. A no-
observed-effect level (NOEL) of 136 mg/m³ (30 ppm) in mice can be
estimated.

Similar degenerative changes of the olfactory epithelium and
hyperplasia have been demonstrated in rats. The reported NOEL value
for 1,3-dichloropropene from a well-designed study was 45.4 mg/m³;
a NOEL of 136 mg/m³ has been reported for the cis-isomer.

A 90-day oral study on rats indicated a NOEL of 3 mg/kg body
weight. The only observed effect at the next higher dose level of 10
mg/kg body weight was an increase in relative kidney weight in the
male.

In a 2-generation, 2-litter, inhalation study on rats, doses of
up to 408.6 mg/m³ (90 ppm) did not show adverse effects on the
reproduction parameters examined. However, the highest dose level of
408.6 mg/m³ induced maternal toxicity, as evidenced by decreased
growth and histopathological changes in the nasal mucosa. A NOEL of
136.2 mg/m³ (30 ppm) was established for maternal toxicity.

Inhalation teratogenicity studies on rats and rabbits did not
indicate teratogenic potential for 1,3-dichloropropene at exposure
levels up to 1362 mg/m³, but embryotoxicity (reduction in litter
size and increase in resorption rates) was seen in the rat. Maternal
toxicity was observed in both rats and rabbits at dose levels of
544.8 mg/m³ (120 ppm) or more.

In most of the studies, cis- and trans-1,3-dichloropropene
and mixtures were mutagenic in bacteria with, and without, metabolic
activation. Pure 1,3-dichloropropene and pure cis-1,3-
dichloropropene were found to be negative in bacteria. Glutathione
was shown to prevent the mutagenic activity of 1,3-dichloropropene
in bacteria. Cis-1,3-dichloropropene was negative in a gene
mutation assay with V79 Chinese hamster cells as well as in the
Chinese hamster ovary HPRT test.

Cis- and trans-1,3-dichloropropene induced unscheduled DNA
synthesis in HeLa S₃ cells. In rat hepatocytes, 1,3-
dichloropropene did not elicit significant DNA repair. 1,3-
Dichloropropene was positive in the Bacillus subtilis strain H17
microsome rec-assay with metabolic activation.

In Chinese hamster ovary cells, cis- and trans-1,3-
dichloropropene induced chromosome damage in the presence of
metabolic activation but, in another study, 1,3-dichloropropene was
positive without metabolic activation. Cis-1,3-dichloropropene did
not induce chromosomal damage in rat liver cells, but induced sister
chromatid exchange in Chinese hamster ovary cells with, and without,
metabolic activation and in Chinese hamster V79 cells without
activation.

1,3-Dichloropropene was negative in a bone marrow micronucleus
test on mice and in a sex-linked, recessive lethal assay on
Drosophila melanogaster.

Carcinogenicity studies were carried out on mice and rats.
Technical 1,3-dichloropropene (containing 1% epichlorhydrin) was
administered by gavage for 2 years. In mice, a significant increase
in epithelial hyperplasia and transitional cell carcinomas in the
urinary bladder, an increase in lung tumours, a slight increase in
tumours of the liver, and an increase in epithelial hyperplasia and
squamous cell papillomas or carcinomas in the forestomach were
found. In rats, increases in the incidence of neoplastic nodules in
the liver and of squamous cell papillomas or carcinomas of the
forestomach were observed.

The carcinogenicity in mice and rats of 1,3-dichloropropene
(without epichlorohydrin) was investigated in 2-year inhalation
studies. In mice, increased incidences of hyperplasia of the urinary
bladder, the forestomach, and the nasal mucosa were observed. There
was an increase in the incidence of benign lung tumours. Some toxic
changes in the olfactory mucosa of the nasal cavity were also seen
in rats, but no increase in tumour incidence.

Epichlorohydrin was shown to produce forestomach tumours in a
gavage study and nasal cavity tumours in an inhalation study on
rats; a carcinogenic effect on the urinary bladder cannot be
excluded for 1,3-dichloropropene administered orally to mice.

Mode of Action

Given that the major metabolic route of elimination of 1,3-
dichloropropene is via conjugation with glutathione, it is to be
expected that situations that affect tissue glutathione (non-protein
sulfhydryl) concentrations may modify the effects of the compound.
1,3-Dichloropropene itself depletes the glutathione content of a
variety of tissues, especially those that are the initial points of
entry into the body, i.e., predominantly the forestomach and liver
following gavage administration, and the nasal tissue after
inhalation exposure. Decreases in nasal epithelium and forestomach
glutathione occurred in mice after inhalation of 1,3-dichloropropene
concentrations exceeding 22.7 mg/m³ (5 ppm) and 113.5 mg/m³ (25
ppm), respectively.

The toxicity of 1,3-dichloropropene in animals occurs at
exposures that deplete glutathione and prior reduction of tissue
glutathione exacerbates it. Long-term inhalation of concentrations
higher than 90.8 mg/m³ (20 ppm) results in degeneration and
hyperplasia of nasal and stomach epithelia in mice, and long-term
inhalation at 272.4 mg/m³ (60 ppm) causes degeneration of nasal
tissue in rats.

The protective role of glutathione has been further highlighted
by studies demonstrating that covalent binding of ¹⁴C-1,3-
dichloropropene to mouse forestomach increased as the non-protein
sulfhydryl content decreased. Similarly, in in vitro test systems,
the genotoxicity of 1,3-dichloropropene and its minor oxidative
(cytochrome P-450) metabolite (1,3-dichloropropene oxide) was
markedly ameliorated by glutathione.

1.1.5 Effects on human beings

The exposure of the general population through air, water, or
food is unlikely.

Studies have shown that occupational exposures are generally
below 4.54 mg/m³ (1 ppm), but higher levels have also been
reported (up to 18.3 mg/m³ during filling or nozzle changing).
Occupational exposure is likely to be through inhalation and via the
skin. Irritation of the eyes and the upper respiratory mucosa
appears promptly after exposure. Inhalation of air containing
concentrations of > 6810 mg/m³ (> 1500 ppm) resulted in serious
signs and symptoms of poisoning; lower exposures resulted in
depression of the central nervous system and irritation of the
respiratory system. Dermal exposure caused severe skin irritation.

Some liver and kidney function changes were reported in a group
of 1,3-dichloroprepene applicators at the end of the application
season. However, the cause-effect relationship has been contested.

Some poisoning incidents have occurred in which persons were
hospitalized with signs and symptoms of irritation of the mucous
membrane, chest discomfort, headache, nausea, vomiting, dizziness,
and, occasionally, loss of consciousness and decreased libido. Three
cases of haematological malignancies have been attributed to an
earlier accidental overexposure to 1,3-dichloropropene, but the
cause-effect relationship remains uncertain.

The fertility status of workers employed in the production of
chlorinated three-carbon compounds was compared with a control
group. There was no indication of an association between decreased
fertility and exposure.

1.2 Conclusions

General population: In view of the low or non-existent exposure to
1,3-dichloropropene, the risk to the general population is
negligible.

Occupational exposure: Filling operations and field applications
may lead to operator exposure exceeding the maximum allowable
concentration, when appropriate safety precautions have not been
taken.

Environment: Provided that 1,3-dichloropropene is used at the
recommended rate, it is unlikely to attain levels of environmental
significance and is unlikely to have adverse effects on populations
of terrestrial and aquatic organisms.

1.3 Recommendations

* Filling operations and field applications of 1,3-
dichloropropene should only be conducted taking appropriate
safety precautions, in order to ensure that exposure levels do
not exceed the maximum allowable concentrations of 1,3-
dichloropropene.

* Studies should be conducted to investigate the metabolic fate
of trans-1,3-dichloropropene in mammals and the potential
role that oxidative metabolites of this isomer may have in
mediating 1,3-dichloropropene toxicity.

* Glutathione transferase mediates the protective effect of
glutathione against the toxicity of 1,3-dichloropropene. It is
recommended that studies should be carried out to compare the
relative enzyme kinetics of human glutathione S-transferase
from various tissues with enzyme activity from comparable
animal tissues.

* The available data on the protective role of glutathione should
be consolidated and published in the open literature.

* Part of the genotoxicity of dichloropropene is mediated by
oxidative metabolism. It is recommended that studies be
undertaken to identify the responsible cytochrome P-450
isoenzyme and compare its activity with human P-450 isoenzymes.

* The confounding role of epichlorohydrin in oral gavage
carcinogenicity studies should be clarified.

2. IDENTITY, PHYSICAL AND CHEMICAL PROPERTIES, ANALYTICAL METHODS

2.1 Identity

Primary constituents

Chemical structure

Chemical formula C₃H₄Cl₂

Relative molecular mass 110.98

Chemical name 1,3-dichloropropene; (IUPAC);
dichloro-1,3-propene; (F-ISO);
1,3-dichloro-1-propene; (CA).

Common synonyms gamma-chloroallylchloride,
1,3-dichloropropylene

Trade name TELONE II^(R), D-D 92

CAS registry number 542-75-6 ( cis- and trans-isomers)
cis-isomer: 10061-01-5
trans-isomer: 10061-02-6

RTECS registry number UC8310000

EINECS number 208-826-5

The commercial product is a mixture of cis- and trans-
isomers and is more than 92% pure. In the past, 1% epichlorohydrin
was added as a stabilizer, but nowadays an epoxidized vegetable oil
is used.

Other names are: Dedisol C, Nematox II, D-D 95, Telone 2000
(Hayes, 1982; Worthing & Hance, 1991).

2.2 Physical and chemical properties

Freezing point - 85 °C^a ( cis-isomer)

Boiling point 103.8-105.2 °C ( cis-isomer)^a
111.0-112.0 °C ( trans-isomer)^b
108.0 °C (1,3-dichloropropene)

Vapour pressure at 25 °C 4850 Pa ( cis-isomer)^a
3560 Pa ( trans-isomer)^b
3.7 kPa (20 °C) (1,3-dichloropropene)

Relative density (D 23/4) 1.221 kg/litre ( cis-isomer)^a
(D 20/4) 1.214 kg/litre ( trans-isomer)^b
Water solubility 2.45 ( cis-isomer)^a
(at 20 °C, in g/litre) 2.49 ( trans-isomer)^b
2.0 (1,3-dichloropropene)

Flash point 28.5 °C ( cis-isomer)^a
28.0 °C ( trans-isomer)^b
25.0 °C (1,3-dichloropropene)

Self-ignition 555 °C ( cis-isomer)^a
534 °C ( trans-isomer)^b

Log P octanol/water 1.82 at 20 °C ( cis-isomer)^a
partition coefficient 2.22 at 25 °C ( trans-isomer)^b
1.4-2.0 (1,3-dichloropropene)

K(OM/V^c 14 ( cis-isomer)
15 ( trans-isomer)

K (OM/V)^c 14 ( cis-isomer)

15 ( trans-isomer)

^a purity 98.1%;
^b purity 96.7%;
^c K(OM/V) = µg adsorbed per g of organic matter (soil)
µg dissolved per ml water phase

From: Leistra (1970), Krijgsheld & van der Gen (1986), Bennett &
Ridge (1989), Schuurman (1989), van Hooidonk (1989), O'Connor
(1990a).

Neither the cis- nor the trans-isomer produces gas in
contact with water, and they are not highly flammable in contact
with diatomite.

1.3-Dichloropropene is a colourless to amber coloured liquid
with a penetrating, irritating, chloroform-like odour. The technical
product is > 92% pure. The physical properties of a cis/trans
mixture depend on the ratio of the isomers (Yang, 1986).

Saturated atmosphere: 167 980 mg/m³ (37 000 ppm) at 25 °C.
Explosive limit: 195 220 mg/m³ (43 000 ppm) (80 °C). Miscible with
acetone, benzene, carbon tetrachloride, heptane, and methanol
(Sittig, 1980; Hayes, 1982; Worthing & Hance, 1991).

Van Hooidonk (1989) and O'Connor (1990a) described methods to
determine the water- and/or fat solubility of cis- and trans-
1,3-dichloropropene using gas chromatography and ECD and/or FID
detection.

Details on ultraviolet/visible, infrared, and nuclear magnetic
resonance spectra are given by O'Connor (1990a).

2.3 Conversion factors

1 ppm (91.2% 1,3-dichloropropene) = 4.54 mg/m³ at 25 °C at 1
atm (Krijgsheld & Van der Gen, 1986; Breslin et al., 1987).

2.4 Analytical methods

Methods have been developed for the determination of 1,3-
dichloropropene ( cis- and trans-isomers) and of 1,2-
dichloropropane in air, soil, water, and crops, and the degradation
product 3-chloroallyl alcohol ( cis- and trans-isomers) in soil
and crops (see Tables 1 and 2). Current methods are based on gas
chromatography (GC).

2.4.1 Sampling

In the case of crops and soil, the need for special care in the
handling of samples and extracts has been stressed, because of the
high volatility of 1,3-dichloropropene.

To minimize loss of residue by volatilization, soil samples
should be deep frozen as soon as possible after sampling, and
shipped to the laboratory for analysis in sealed containers with a
minimum of delay (Rexilius & Schmidt, 1982). The period of storage
of deep frozen samples in the laboratory should also be kept as
short as possible (Wallace, 1979). At -20 °C, Hermann & Matsuyama
(1982) found a slow decline in the contents of all components of
"MIX D/D", indicating a maximum acceptable storage period of 2
months. No loss occurred in 4 months at a temperature of -80 °C.

Table 1. Methods of analysis for 1,3-dichloropropene and 1,2-dichloropropane in food and biological media

Sample Extraction Clean-up Detection and Recovery Limit of Reference
quantitation determination

Crops, steam distillation absorption chromatography gas chromatography -^a 0.01 mg/kg Rexilius & Schmidt
Soil and diethyl ether on acidic alumina with ECD and FID (1,3-dichloropropene) (1982); Shell (1985);
extraction 0.1 mg/kg Wallace (1974)
(1,2-dichloropropane)

trapped in - gas chromatography -^a - Shell (1980)
ethyl acetate with ECD

Water steam distillation absorption chromatography gas chromatography -^a 0.001 mg/kg Shell (1985)
and diethyl ether on acidic alumina with ECD (1,2-dichloropropane)
extraction

Air - absorption on Tenax GC, gas chromatography -^a -^a Leiber & Berk (1984)
desorption with isooctane with ECD

Air - absorption on charcoal, gas chromatography 90-100% 0.005 mg/m³ Van Sittert et al.
desorption with with FID (1977); Sherren &
carbon disulfide Woodbridge (1987a,b)

Air - absorption on charcoal, gas chromatography 85% 23 ng^b Albrecht et al.
desorption with with ECD (1986)
methanol/benzene

Blood hexane - gas chromatography 90% cis and trans Kastl & Hermann
with ⁶³Ni-ECD or 1,3-dichloropropene, (1983)
GS-MS (SIM) 5.3-5.9 ng/litre

^a Data on recovery and/or limit of determination not given.
^b Given as mass/tube.

Table 2. Methods of analysis for 3-chloroallyl alcohol in food and biological media

Sample Extraction Clean-up Detection and Recovery Limit of Reference
quantitation determination

Crop, diethyl ether derivatization with 3,5- gas chromatography - crops: 0.05 mg/kg Rexilius & Schmidt
Soil dinitrobenzoyl chloride with ECD soil: 0.02 mg/kg (1982)
and pyridine, absorption Wallace (1974)
chromatography on acidic
alumina

Crop, steam-distillation, esterification with capillary gas- - - Shell (1978)
Soil, hexane extraction trifluoroacetic chromatography - -
Water with diethyl ether anhydride with ECD - water: 0.002 mg/kg Shell (1985)

Crop samples should be deep frozen as soon as possible after
sampling, and water samples should be chilled or deep frozen; both
should be shipped and stored under the same precautions as soil
(Wallace, 1976b; Rexilius & Schmidt, 1982).

2.4.2 Determination of residues in crops and soil

A combined method for the determination and confirmation of 1,3-
dichloropropene, 1,2-dichloropropane, and chloroallyl alcohol (3-
CAA) in crops and soil has been developed (Wallace, 1974; Shell,
1976). After steam distillation and extraction and clean up, the
determination of residues is carried out using gas chromatography
(electron capture (ECD) and flame ionization (FID)). The chloroallyl
alcohol is derivatized, followed by a clean up and determination
using ECD. Confirmation of the identity of residues is carried out
by combined gas chromatography-mass spectrometry (GC-MS).

With this method, the lower limit of determination in most crop
and soil samples is 0.01 mg/kg for 1,3-dichloropropene and 0.1 mg/kg
for 1,2-dichloropropane. For 3-chloroallyl alcohol, the lower limit
of determination is 0.05 mg/kg for crops and 0.02 mg/kg for soil
(Wallace, 1974; Rexilius & Schmidt, 1982; Shell, 1985).

Alternative methods are described by Shell (1980) in which 1,3-
dichloropropene and 1,2-dichloropropane are trapped in ethyl acetate
and directly determined, without clean up by capillary GC with ECD.
The 3-chloroallyl alcohol residues are steam-distilled without acid
or alkali and "free residues" are washed with hexane, and extracted
into diethyl ether. The alcohol residues are then esterified by
trifluoroacetic anhydride and determined with capillary GC with ECD
(Shell, 1978).

Shell (1984) described a method based on the previously
mentioned techniques of extraction and preparation of extracts;
however, in both crops and soil, residues are determined by
capillary GC with a Hall electrolytic conductivity detector (HECD).
In addition, residues of 3-chloroallyl alcohol are determined
without derivatization. The lower limit of determination is 0.01
mg/kg.

2.4.3 Determination of residues in water

The methods described in section 2.4.2 can be adapted for the
determination of residues of 1,3-dichloropropene, 1,2-
dichloropropane, and 3-chloroallyl alcohol in water (Wallace, 1974).
The alternative methods mentioned under section 2.4.2 also include
procedures for water analysis (Wallace, 1974; Shell, 1978) (see
Table 1).

A laboratory analytical method (US EPA method 524.2), developed
to monitor drinking-water, involves a standard inert (helium) gas
purge extraction, isolation on a solid-phase trap (gas
chromatography with a fused silica capillary column (FSCC) coated
with a film of cyanopropylphenyl-dimethylpolysiloxane polymer),
thermal desorption, and gas chromatography and identification and
measurement with a low-cost, bench-top ion trap detector (ITD),
which functions as a mass spectrometer. At a concentration of 0.2
µg/litre, the total mean measurement accuracy was 99% for trans-
1,3-dichloropropene ( cis-isomer not measured) and 103% for 1,2-
dichloropropane (Eichelberger et al., 1990).

Telliard (1990) described broad-range methods for the
determination of pollutants in waste water. US EPA method 1624 is
used to determine purgeable organic compounds by calibrated isotope
dilution or internal standard GC-MS and by reverse search of a GS-MS
run for the analytes. The first technique can be used to determine
1,2-dichloropropane and the second, 1,3-dichloropropene.

2.4.4 Determination of residues in air

Methods based on the use of solid absorbent traps or direct gas
sampling procedures in conjunction with GC analysis have been
described for the determination of 1,3-dichloropropenes and 1,2-
dichloropropane in air.

Leiber & Berk (1984) used Tenax-GC as an absorbent to monitor
concentrations of chlorinated aliphatic hydrocarbons in workspace
air. Isooctane, containing 1,3,5-tribromobenzene as internal
standard, was used for the desorption of the hydrocarbons.
Recoveries of 1,3-dichloropropenes were in the range of 1.8-18
mg/m³. A similar method was used by Van Sittert et al. (1977) and
Albrecht et al. (1986), but, in this case, the trapping medium was
activated charcoal. It appears that charcoal had a better trapping
capacity than Tenax-GC (Brown & Purnell, 1979) for 1,3-
dichloropropenes. Trapped vapours were desorbed using carbon
disulfide (recovery 90-100%) (van Sittert et al., 1977; HSE, 1990)
or 1% v/v methanol-benzene mixture (mean recovery 85%) (Albrecht et
al., 1986). Van Sittert et al. (1977) could determine 0.05 mg/m³
of the cis- and trans-isomers of 1,3-dichloropropene in air.

All authors warned that care should be taken in the handling of
trapped samples.

Parker et al. (1982) used charcoal filters to determine 1,3-
dichloropropene and 1,2-dichloropropane levels in air.

Others have used more direct gas sampling procedures. Air from
the head space above soil and water in sealed containers has been
sampled and directly determined by GC with ECD or FID. Gas samples
were trapped by injecting the air into an organic solvent, such as

xylene or hexane, before GC analysis (Williams, 1968; Leistra, 1970;
Abdalla, 1974; Abdalla et al., 1974; McKenry & Thomason, 1974; van
Dijk, 1980).

2.4.5 Determination of residues in food

Reinert et al. (1983) described a dynamic heated headspace
analysis of organic compounds including 1,2-dichloropropane in fish
and shellfish tissue samples. The method included solvent (carbon
disulfide) desorption of activated carbon adsorbent and
determination with capillary column gas chromatography with a flame
ionization detector. Recoveries were rather low (approximately 40-
70%). Hiatt (1983) described a vacuum distillation apparatus and a
procedure developed for the analysis of fish tissue. The volatile
compounds were distilled from the sample and characterized by gas
chromatography/mass spectrometry using fused silica capillary column
(FSCC).

A method was described by Daft (1989) to determine fumigants and
related chemicals in fatty and non-fatty foods. The method started
with liquid extraction with isooctane, when necessary with co-
extraction with a mixture of acetone/NaCl in 25% phosphoric acid and
isooctane. The isooctane extracts were analysed using gas
chromatography. Excess fat was removed by micro-Florisil columns.
The determination was done by ECD and HECD (Hall electroconductivity
detection). Overall mean recovery was 73% from fatty foods and 78%
from non-fatty foods; the recovery from both sample types after
further Florisil chromatography was 55%.

2.4.6 Determination of 3-chloroallyl alcohol

In Table 2, analytical methods are described to determine 3-
chloroallyl alcohol in food and biological media.

2.4.7 Determination of mercapturic acids in urine

In Table 3, methods are described to determine metabolites of
1,3-dichloropropene in urine.

Van Welie et al. (1989) used an analytical method to determine
N-acetyl- S-( cis- and trans)-3-chloroprop-2-enyl-L-cysteine
( cis- and trans-DCP-MA) in urine, based on capillary gas
chromatography with sulfur-selective detection. An internal standard
N-acetyl- S-(benzyl)-L-cysteine and hydrochloric acid (resulting
in a pH 1-2) were added to urine samples. The samples were extracted
with ethyl acetate and the latter evaporated; the residues were
methylated and determined using gas chromatography-flame photometric
detection (GC-FPD). GC-MS was used for identification. The limits of
determination were 0.107 mg/litre for cis-DCP-MA and 0.115
mg/litre for trans-DCP-MA.

Table 3. Methods of analysis for metabolites of 1,3-dichloropropene in urine

Sample Extraction Clean-up Detection and Recovery Limit of Reference
derivatization derivatization quantitation determination

N-acetyl-S[cis-chloroprop-2-enyl]cysteine

Urine ether derivatization with gas chromatography with - - Osterloh et
(human) diazomethane etherate electron impact ionization al. (1984)
silicone membrane
separator, mass spectrometry

Urine ethyl acetate derivatization with gas chromatography with cis-isomer and for cis- and van Welie
(human) diazomethane etherate fused silica WCOT columns, trans-isomer trans-isomer range et al. (1989)
sulfur-selective detection 105% 107-115 ng/ml

Urine ethyl acetate derivatization with gas chromatography with cis-isomer for the different Onkenhout et
(rat) diazomethane nitrogen selective detection 66-83% methods and for al. (1986)
or negative chemical trans-isomer cis- and trans-isomer
ionization/mass spectrometry 56-85% range 20-550 ng/ml

3. SOURCES OF HUMAN AND ENVIRONMENTAL EXPOSURE

3.1 Natural occurrence

As far as is known, 1,3-dichloropropene does not occur
naturally.

3.2 Man-made sources

3.2.1 Production levels and processes

1,3-Dichloropropene is produced by the high-temperature
chlorination of propylene or from 1,3-dichloro-2-propanol by
dehydration with POCl₃ or with P₂O₅ in benzene.

1,3-Dichloropropene is a by-product in the synthesis of allyl
chloride; 1,2-dichloropropane and to a lesser extent, 2,3-
dichloropropene are also formed. In some commercial products,
marketed for soil fumigation (mix D/D, Telone), 1,3-dichloropropene
is the major and active ingredient (50-80% of total), but 1,2-
dichloropropane (20-40%) and 2,3-dichloropropene (5-6.5%) are also
present (Krijgsheld & Van der Gen, 1986).

Before 1978, about 25 000 tonnes of 1,3-dichloropropene were
produced annually in the USA (Flessel et al., 1978). In Italy, 2187
tonnes were produced in 1972 (De Lorenzo et al., 1977). Over 1285
tonnes of 1,3-dichloropropene-containing pesticides were used in
California in 1971 (Yang, 1986), while in the period 1970-77, the
amount applied was approximately 1.8-2.7 million kg. In 1981, over
7.2 million kg of 1,2-dichloropropane- and 1,3-dichloropropene-
containing fumigants were used in California (California State Water
Resources Control Board, 1983).

The estimated production in Europe in 1979 was 6-7
kilotonnes/year.

1,2-Dichloropropane, present as an impurity in the fumigant,
does not add to the desired biological effects, but may, on the
contrary, have unwanted ecotoxicological consequences. Therefore,
there has been a more recent development to stop the use of the
"impure" fumigant and to move to a purer preparation of 1,3-
dichloropropene (> 90%) (Krijgsheld & Van der Gen, 1986).

3.2.2 Use

1,3-Dichloropropene, the main ingredient of Telone II, was
introduced in 1956 as a commercial preplant soil fumigant for the
control of nematodes in crops, such as vegetables, potatoes, and
tobacco. It is applied from a tractor-drawn, high pressure injection

system into the soil. The soil is treated prior to the planting of
crops (De Lorenzo et al., 1977; Hayes, 1982; Maddy et al., 1982).

1,3-Dichloropropene is effective against soil nematodes
including root-knot, meadow, sting and dagger, spiral and sugar beet
nematodes. The rates of application are determined according to the
crop to be grown and the soil conditions, but generally lie within
the range of 75-200 kg/ha (occasional maximum of 700 kg/ha)
(Krijgsheld & van der Gen, 1986; Shell, IPM, 1990).

3.2.3 Sources of pollution

1,3-Dichloropropene is used extensively as a soil fumigant for
the treatment of agricultural land. After application, part of the
chemical will evaporate and escape from the soil. Although
significant biodegradation and abiotic decomposition will occur in
the soil, there is a limited risk of leaching down to groundwater
level (see section 4.1.3). The 1,3-dichloropropene that is used for
fumigation is contaminated with 1,2-dichloropropane and 2,3-
dichloropropene. At application rates of "MIX D/D" ranging from 200
to 400 kg/ha, this may mean an input of 40-160 kg of 1,2-
dichloropropane and 10-25 kg of 2,3-dichloropropene per hectare of
land (Krijgsheld & van der Gen, 1986). The potential for groundwater
contamination has been reduced by reducing the 1,2-dichloropropane
content of the products used in agriculture.

4. ENVIRONMENTAL TRANSPORT, DISTRIBUTION, AND TRANSFORMATION

As with other fumigants, the performance of 1,3-dichloropropene
as a nematocide is dependent on a number of important factors
influencing the movement of soil fumigants, e.g., the chemical and
adsorptive characteristics of the toxicant (vapour pressure,
solubility, diffusion coefficient, the distribution of the fumigant
through air, water, and solid phases of the soil) and physical
factors, such as temperature, moisture, organic matter, soil
texture, and soil profile variability (Munnecke & van Gundy, 1979;
NTP, 1985; Yang, 1986).

Dichloropropenes can enter the aquatic environment as discharges
from industrial effluents, through run off from agricultural land,
and from municipal effluents.

The stability and mobility of 1,3-dichloropropene and 1,2-
dichloropropane in air, soil, and groundwater are influenced by
several processes, as shown in Fig. 1.

4.1 Transport and distribution between media

(See also section 4.1 of 1,2-dichloropropane and subsections).

4.1.1 Air

Tuazon et al. (1984) calculated that, at a daytime OH-radical
concentration of 2 x 10⁶/cm³ (8 x 10^-8 ppm) in the
troposphere, the half-lives of cis- and trans-1,3-
dichloropropene would be 12 and 7 h, respectively. The half-life for
1,2-dichloropropane is > 313 days for a 24-h average OH-radical
concentration of 1 x 10⁶/cm³. For the reaction with ozone at a
background level in the troposphere of 80 µg/m³ (0.04 ppm), the
half-lives of cis- and trans-1,3 dichloropropene, were
calculated to be 52 and 12 days. Direct phototransformation seems to
be insignificant compared with the two other reactions, but may be
enhanced in the presence of atmospheric particulates.

4.1.2 Water

Since the chloropropenes have a relatively low water solubility
and high volatility, they will have a tendency to disappear rapidly
from an aqueous medium. The half-life of evaporation of a chemical
from a certain body of water will increase with the depth of the
water and continuous evaporation will become increasingly dependent
on sufficient agitation in the water. Evaporation can be expected to
contribute significantly to the disappearance from the aquatic
environment (Krijgsheld & van der Gen, 1986).

Dilling et al. (1975) determined the rate of evaporation of 1,3-
dichloropropene ( cis- and trans-) from water at the 1 mg/litre
level under ambient conditions. The time required for the compound
to be reduced by 50% was 31 min and by 90%, 98 min.

Yon et al. (1991) determined that the half-life of evaporation
of 1,3-dichloropropene ( cis- and trans-isomers) from water was
less than 5 h.

4.1.3 Soil

The persistence of 1,3-dichloropropene depends on chemical
degradation, volatilization, microbial transformation, photochemical
transformation, type of soil, water content of soil, and uptake into
organisms. Thomason & McKenry (1974) studied the quantitative as
well as the qualitative aspects of the movement and fate of 1,3-
dichloropropene under various conditions in different types of soil.

Since 1,3-dichloropropene is used as soil fumigant, some
information is available on the distribution of the compound in
soil. The adsorption of 1,3-DCP on soil was found to be proportional
to the organic matter content of the soil. The K(om/v)s^a for cis-
and trans-1,3-dichloropropene were estimated to be 14 and 15,
respectively, independent of ambient temperature (Leistra, 1970).
Similar soil/water distribution coefficients (23 and 26), based on
organic carbon content, were reported by Kenaga (1980).

McKenry & Thomason (1974) demonstrated that high soil moisture
was a major limiting factor in the total diffusion when soil
moisture in the field approached field capacity. In contrast,
Munnecke & van Gundy (1979) stated that soil moisture was a very
important factor in that gaseous compounds are most effective in
killing organisms when they are in a moist environment.

Environmental transformation of 1,3-dichloropropene results from
microbial action, with the exception of the initial hydrolysis of
cis- and trans-1,3-dichloropropene to 3-chloroallyl alcohol
(Castro & Belser, 1966; Belser & Castro, 1971). The pathway for the
transformation of 1,3-dichloropropene is given in Fig. 2.

^a See section 2.2.

4.1.3.1 Hydrolysis

Cis- and trans-1,3-dichloropropene can be hydrolysed in soil
to 3-chloroallyl alcohol (see Fig. 2). Hydrolysis rates for 1,3-
dichloropropenes range from 1 to 3.4% per day, depending on
temperature and moisture content. Hydrolysis rates also vary with
soil type (particle size) because of differences in chemical
diffusion rate and sorption capacity (California State Water
Resources Control Board, 1983).

Using [¹⁴C]-radiolabelled 1.3-dichloropropene in sterile
buffered water at pH 5, 7, or 9 and temperatures of 10, 20, or 30
°C, McCall (1987) found that the rate of hydrolysis was independent
of pH at each temperature, and that the half-lives at temperatures
of 30, 20, and 10 °C were 3.1, 11.3, and 51 days, respectively. One
hydrolysis product, formed during the course of the study, was
identified as 3-chloroallyl alcohol. The alcohol appeared to be
stable to further hydrolytic conversion and was formed in the same
cis-:trans-ratio as the initial 1,3-dichloropropene.

The hydrolysis of cis-1,3-dichloropropene (98.1%) was studied
by O'Connor (1990b). The degradation reactions at all pH values were
shown to follow pseudo first-order behaviour in the EEC-test,
independent of the concentration. The degradation rate constants and
environmental half-lives for cis-1,3-dichloropropene at 25 °C at
pH 4, pH 7, and pH 9 (extrapolated by measuring degradation at
temperatures of 50, 60, and 70 °C, using Arrhenius relationships)
were 100 h, 54.5 h, and 38 h, respectively. (Remark: although the
rate of hydrolysis of cis-1,3-dichloropropene did show some slight
pH dependence, the author stated that this was probably within
experimental error). It is hypothesized that the degradation
proceeds via a resonance stabilized carbonium ion intermediate,
resulting in the formation of a mixture of 3-chloroallyl alcohol and
propenal (see Fig. 3).

Connors et al. (1990) studied the hydrolysis of 1,3-
dichloropropene into 3-chloroallyl alcohol, under laboratory
conditions. A 1.0 µg/litre cis- and trans-1,3-dichloropropene
solution was prepared in a pH 5.5 or pH 7.0 buffer. The half-lives
for the cis- and trans-isomers at 15 and 29 °C (pH 5.5) were
11.0, 2.0 and 13.0, 2.0 days, respectively. At pH 7.0 and 25 °C, the
value was 4.6 days for both isomers.

Determination of the rate of hydrolysis of 1,3-dichloropropene
at 25 °C in 50% aqueous ethanol indicated a half-time of 4 days for
both the cis- and trans-isomers and appeared independent of the
concentration in the range of 10-1000 mg/litre. Only small
differences were observed in disappearance rates at pH levels of 5.5
and 7.5. The effect of temperature was clearly demonstrated: at 29
°C, the half-life for cis-1,3-dichloropropene was 1.5-2.0 days,
while, at 2 °C, the half-life was estimated to be 91-100 days
(Krijgsheld & Van der Gen, 1986).

The rates of transformation of the cis- and trans-isomers in
soil layers of 0.1-0.2 m and 0.4-0.5 m in a bulb field in the
Netherlands were determined in the laboratory. The initial contents
of added 1,3-dichloropropene were approximately 12 and 62 mg/kg.
Incubation took place at 15 °C. The half transformation time was
about 4 days for both isomers. After 2 weeks, only small amounts
(1%) of the initial amount were left. The transformation was slower
in soil with the higher initial content (62 mg/kg) than in soil with
12 mg/kg. The half-life was approximately 19 days for both isomers.
Only small amounts were left after one month (Van der Pas & Leistra,
1987).

The behaviour of technical grade 1,3-dichloropropene in the soil
from 4 fields (soil containing 13.2-24.6% of organic matter) was
studied in the laboratory. The transformation rates of cis- and
trans-1,3-dichloropropene were measured in soil samples taken from
the ploughed layer of the fields. Pure 1,3-dichloropropene was added
at 35 µlitre/kg moist soil. The transformation in soil from one of
the fields could be approximated with first- order kinetics during
the whole incubation period of 21 days. The half-lives of the cis-
and trans-isomers at 10 °C were 17 and 20 days, respectively. In
soil from the 3 other fields, transformation of 1,3-dichloropropene
with approximate first-order kinetics in the initial period of 7-14
days was followed by a period of accelerated transformation. The
concentration dropped below the limit of determination (0.1 mg/kg
dry soil), 14-21 days after the start of the incubation. Presumably,
soil microorganisms adapted their enzymes, resulting in an increased
rate of transformation (Van den Berg & Leistra, 1989).

In 6 loamy soils, transformation was gradual and pseudo first-
order for 3-6 days, and then, very rapid. There was no difference
between the transformation of the cis- and trans-isomers of 1,3-
dichloropropene in these soils. When the initial content in dry soil
was 62-80 mg/kg, less than 0.2% remained after a week (temperature
15 °C). The greatly accelerated transformation that occurred after a
short time lag suggests that the soils contained microorganisms that
could transform 1,3-dichloropropene effectively (Smelt et al.,
1989).

Rapid transformation was found in 6 loamy soils from fields
fumigated once or twice previously, as well as from fields never
treated; after 7 days, less than 0.2% of the applied dose (3.7, 18,
or 92 mg 1,3-dichloropropene/kg) remained. The incubation
temperature was 15 °C. However, with an initial content of 470
mg/kg, the transformation was suppressed with a half-life of 33
days. In another loamy soil, which showed no accelerated
transformation pattern, the pseudo half-lives increased from 4.3 to
36 days, when initial content of 1,3-dichloropropene was raised from
3.7 to 470 mg/kg (Smelt et al., 1989).

4.1.3.2 Volatilization

Volatilization and diffusion in the vapour phase are the most
significant mechanisms for the environmental dispersal and dilution
of 1,3-dichloropropene and 1,2-dichloropropane. Volatilization rates
from soil surfaces depend on water solubility and vapour density as
well as on soil properties, such as temperature and moisture
content, the depth of application, and surface wind velocity.
Estimates of volatilization of cis-1,3-dichloropropene from soil
have ranged from 20 to 75%.

D-D 92 was applied to sandy clay loam soil in a polyethylene
tunnel and the air in the tunnel was monitored continuously for 1,3-
dichloropropene for 4 weeks. The temperature in the tunnel was 18-29
°C. D-D 92 was injected by hand at a dose rate of 225 kg/ha, at a
depth of 15 cm. About 45% of the applied D-D 92 was volatilized as
1,3-dichloropropene in the first week, increasing to 54% after 4
weeks. No more than 5% was found as 1,3-dichloropropene or 3-
chloroallyl alcohol in the soil at the end of the 4-week period
(Sherren & Woodbridge, 1987c).

4.1.3.3 Uptake in crops

Residues in edible crops arising from the use of "MIX D/D" or
1,3-dichloropropene have only been detected in small amounts (<
0.02 mg/kg). The most obvious reason for this is the fact that crops
are not normally planted until most of the product has been
eliminated. Under certain conditions, where low concentrations of
1,3-dichloropropene persist for long periods of time, plants will
absorb measurable quantities. Uptake has been shown to occur in
potato tubers in sandy loam soil treated with ¹⁴C-1,2-
dichloropropane and ¹⁴C-1,3-dichloropropene 6 months prior to
planting (application rate 290 litre/ha). The total radioactivity
(expressed as 1,3-dichloropropene equivalents) in the tubers was 7
µg/kg (Roberts & Stoydin, 1976).

Tomatoes, bush beans, and carrots absorbed ¹⁴C-1,3-
dichloropropene from vermiculite culture solution and sand. During
24 h, the compound was absorbed and translocated through the plants.

3-Chloroallyl alcohol was also readily absorbed, but to a lesser
extent than dichloropropene. Comparison of the metabolism of 1,3-
dichloropropene and 3-chloroallyl alcohol showed rapid reversion to
the general carbon pool, the half-lives for 1,3-dichloropropene and
3-chloroallyl alcohol being 1.5 and 4.4 h, respectively (Berry et
al., 1980).

4.1.3.4 Movement in soil

Vapour diffusion is usually the most important mode of downward
movement for "MIX D/D". McKenry & Thomason (1974) injected either
Telone or "MIX D/D" into a series of soils at 11 different sites in
California. The moisture levels, temperatures, cultivation, and soil
profiles at the sites varied. The movement was studied during 13 and
69 days. The application rates ranged from 600 up to 2300 kg/ha. It
was concluded that:

* There was a substantial and downward movement of all the
components.

* Downward movement was greatest in open-textured soils that were
sufficiently moist but not saturated; the fumigant was
detectable at a depth of a few metres.

* Downward movement was encouraged by deep cultivation in soils
with horizons of low porosity.

In the United Kingdom, however, Wallace (1979) found only traces
of fumigant in the 40-60 cm layer, after an injection at a depth of
18 cm. Wallace (1976a) had found comparable results in soil in
Germany. In the European studies, the diffusion was slower, because
the applications were made in late autumn; soils were wetter,
colder, and heavier in texture. Thus, results from studies carried
out under different agronomic and climatic conditions are not
necessarily comparable.

The vertical and horizontal movements of 1,3-dichloropropene
were studied in a tree-nursery region in the north of the Federal
Republic of Germany. Sounding pipes were used to collect water
samples down to a depth of 4 m using the percussion-boring method.
Further borings were set to a depth of 3 m on days 10-91 after
application of a formulation containing cis- and trans-1,3-
dichloropropene, methylisothiocyanate and 1,2-dichloropropane at 50
ml/m². Soil cores were analysed. 1,3-Dichloropropene showed a
rather high mobility in the soil, as it could be detected at a depth
of 4 m in all soil layers on the fourth day of application. In
samples of the near-surface groundwater, collected 140 days after
application, a concentration of 1.36 µg 1,3-dichloropropene per
litre was found. Ten to 25 m from the treated area, 1,3-
dichloropropene was also found in groundwater after 59 and 140 days
(Rexilius & Schmidt, 1982).

4.1.3.5 Loss under field conditions

Williams (1968) studied the loss of 1,3-dichloropropene under
field conditions in sandy loam and peat soils in Canada. The
application rates were approximately 1000 and 2000 litre "Mix
D/D"/ha, respectively. Eight months later, samples were collected
and residues determined (Table 4).

In studies in the Federal Republic of Germany, Netherlands, and
the United Kingdom, only very low residues (1%) of the amount
originally applied remained after 3 months in the soil (Wallace,
1976a,b; Wallace, 1979).

A comparative trial was carried out in the United Kingdom in
which "MIX D/D" and 1,3-dichloropropene were injected, at a depth of
15 cm, in clay loam at concentrations of 410 and 240 litre/ha,
respectively (Table 5, see also section 4.3.2 of "MIX D/D"). Samples
of soil were taken at depths of 0-20 cm, 20-40 cm, and 40-60 cm, at
6 intervals up to 9´ months after application. As part of normal
recommended agricultural practice, the soil was ploughed 5 weeks
after treatment. Soil samples were analysed for residues of cis-
and trans-1,3-dichloropropene, 1,2-dichloropropane, and cis- and
trans-3-chloroallyl alcohol. There was no significant difference
between the residues of the 1,3-dichloropropene or the 3-chloroallyl
alcohol resulting from the 2 treatments. As expected, no 1,2-
dichloropropane residues were detected in soil samples treated with
1,3-dichloropropene. Residues of the cis- and trans-1,3-
dichloropropenes and cis- and trans-3-chloroallyl alcohols were
detected in all samples up to 9´ months after treatment and down to
the 20-40 cm soil layer. Before the soil was ploughed, the
concentrations of these substances showed little change, and they
were present in all 3 layers, but, after ploughing, the
concentrations decreased gradually (Wallace, 1979).

Table 4. Recovery of cis- and trans-1,3-dichloropropene from
sandy loam or peat soils, 8 months after application of 1000 or 2000
litre "MIX D/D"/ha, respectively

Soil Depth in cm Residue in mg/kg soil
cis-1,3- trans-1,3-
dichloropropene dichloropropene

Peat 0-10 1.4 3.2
10-20 1.8 4.8

Sandy loam 0-10 - -
10-20 0.3 0.4

From: Williams (1968)

Table 5. Residues from the plot treated with 1,3-dichloropropene at 240 litre/ha^a

Concentration in soil (mg/kg)

Interval since Soil depth 1,3-dichloropropenes 1,2-dichloropropane 3-chloroallyl alcohol
application (cm)
(days) cis-isomer trans-isomer cis-isomer trans-isomer

3 0-20 2.02 2.54 < 0.1 1.01 1.01
20-40 5.98 7.32 0.2 3.16 3.34
40-60 0.14 0.15 < 0.1 1.57^b 1.88^b

10 0-20 6.29 7.66 0.1 1.23 1.23
20-40 1.79 2.10 < 0.1 1.09 1.14
40-60 0.52 0.55 < 0.1 3.01^b 3.24^b

23 0-20 6.10 6.10 0.2 2.39 2.39
20-40 3.26 3.20 0.2 1.32 1.32
40-60 0.09 0.08 < 0.1 0.04 0.04

34 NORMAL CULTIVATION (ploughing of the soil)

40 0-20 0.95 1.10 < 0.1 0.45 0.45
20-40 0.97 0.90 < 0.1 0.62 0.62
40-60 0.06 0.04 < 0.1 < 0.02 < 0.02

67 0-20 0.28 0.36 < 0.1 0.70 0.70
20-40 0.04 0.05 < 0.1 0.32 0.26
40-60 0.11 0.09 < 0.1 0.05 0.04

Table 5 (contd)

Concentration in soil (mg/kg)

Interval since Soil depth 1,3-dichloropropenes 1,2-dichloropropane 3-chloroallyl alcohol
application (cm)
(days) cis-isomer trans-isomer cis-isomer trans-isomer

At harvest 0-20 0.08 0.06 < 0.1 0.20 0.20
9´ months 20-40 0.02^c 0.02^c < 0.1 0.04 0.03
40-60 < 0.01 < 0.01 < 0.1 < 0.02 < 0.02

Pre-treatment 0-20 < 0.01 < 0.01 < 0.1 < 0.02 < 0.02
20-40 < 0.01 < 0.01 < 0.1 < 0.02 < 0.02
40-60 < 0.01 < 0.01 < 0.1 < 0.02 < 0.02

^a From: Wallace (1979).
Note: All residues are on a dry weight basis.
^b Anomalous results.
^c Results confirmed by GC/MS.

1,3-Dichloropropene (D-D 95 and Telone II, containing > 92%),
at concentrations of 240, 280, and 290 litre/ha, was injected into
the soil of 3 bulb fields in the Netherlands in the summer. Nine
points were sampled per field and the samples were taken at various
times down to a depth of 3 m. Within a month, the concentrations
decreased to less than 0.2 mg/kg and continued to decline gradually
with time (Van der Pas & Leistra, 1987).

In 2 fields in the Netherlands (soil containing 15.7-24.6% of
organic matter), the spread of the fumigant (application rate 150
litre/ha) through the soil was measured. Only low fumigant
concentrations (about 0.1-0.4 mg/kg) were measured at a depth of 0.3
m. Around the depth of injection (0.15-0.2 m), the ratio of cis-
and trans-isomers changed with time in favour of the trans-
isomer. Cumulative emissions into the air over a period of 3 weeks
were calculated to range from 10 to 20% of the dosage of the cis-
isomer, and 4 to 15% of the trans-isomer (Van den Berg & Leistra,
1989).

4.1.3.6 Results of supervised field trials

A field study was undertaken in France in 1988, in which D-D 92
was applied to the soil prior to planting vines, and the air in the
vicinity of the treated area was monitored for 1,3-dichloropropene.
D-D 92 was applied at approximately 600 kg/ha at a depth of 30-40
cm. The air levels were monitored for 10 days. No samples contained
1,2-dichloropropane at levels above the limit of determination of
0.02 mg/m³. The highest 1,3-dichloropropene concentration found
during the first 24 h (perimeter of the field) was 2.1 mg/m³ and
this declined to 0.02-0.04 mg/m³ after 10 days. Air concentrations
also decreased with increasing distance, downwind (Sherren, 1990).

4.2 Bioconcentration

No data are available on bioconcentration.

4.3 Abiotic degradation

4.3.1 Photodegradation

Li (1979) obtained results comparable with those of Tuazon et
al. (1984) working with ozone, by irradiation of vapour of cis-
and trans-1,3-dichloropropene with a GE-RS sunlamp (see section
4.1.1). The main reaction product was 3-chloropropionyl chloride
with smaller quantities of 3-chloropropionic acid, CO₂, and
phosgene. In this process, the initial reaction was epoxidation of
the double bond. There is evidence of the importance of a surface
reaction in the atmosphere, adsorption on to particulate matter
seems to be necessary for an appreciable direct phototransformation
to occur. Vapour phase photolysis of 1,3-dichloropropene was not

detected after prolonged simulated sunlight irradiation in a
reaction chamber. Photolysis occurred on the photoreactor surface
walls suggesting surface-catalysing reactions. The reaction products
suggest that 12-13% was totally degraded to CO₂ after 5 days of
irradiation. Over 20% was transformed to phosgene.

No data on the photolytic decomposition of the chloropropenes
in water are available. Nevertheless, UVR of these chemicals in
methanol, in a frozen state, or as inclusion in adamantine matrices,
may cause the production of allyl radicals, by cleavage of the
allylic C-Cl bond (Krijgsheld & van der Gen, 1986).

4.4 Biodegradation and biotransformation

Several studies have been performed on the persistence of 1,3-
DCP in soil, after application as a fumigant. Biodegradation by soil
microorganisms does occur, depending on soil type, temperature, and
moisture content. The rate of disappearance ranges from a half-life
of 3 days to one of 37 days, without any consistent correlation with
organic matter content of the soil, or with pH. In sterile soils,
the effect of temperature was minimal (Van Dijk, 1974; Tabak et al.,
1981; California State Water Resources Control Board, 1983). In
general, the rates of disappearance of the cis- and trans-
isomers are similar and tend to increase with moisture content and
temperature, conditions that may increase, not only biodegradation,
but also loss by volatilization or chemical hydrolysis. Although
between 15 and 80% decomposition of field applications of 1,3-
dichloropropene has been shown, the large amount that can be
absorbed (80-90%) can result in soil residues existing months after
application is completed (Van Dijk, 1974; Roberts & Stoydin, 1976;
Sittig, 1980; Krijgsheld & van der Gen, 1986).

In biodegradability studies using a synthetic medium that
contained 5 mg of yeast extract/litre and was inoculated with waste
water, loss of 1,3-dichloropropene was determined after 7 days of
incubation. Significant degradation was observed at 5 and 10 mg of
1,3-dichloropropene/litre and gradual adaptation was shown in
subcultures. The original culture degraded about 50% of the 1,3-
dichloropropene in 7 days, while the third subculture was able to
degrade approximately 85% at both substrate concentrations, in the
same period of time (Tabak et al., 1981).

Battersby (1990a) determined the "ready biodegradability" of
trans-1,3-dichloropropene (95.4% trans- and 0.3% cis-isomer)
using the closed bottle procedure. The substance was not degraded in
this system with a negligible proportion of the theoretical oxygen
demand being consumed during the 28-day incubation period.

The EEC-activated sludge respiration inhibition test was used
to determine the effect of a cis- (51.2-52.2%) + trans- (43.9-
44.1%) mixture of 1,3-dichloropropene containing 0.33% of 1,2-
dichloropropane on the respiration rate of activated sludge. The
EC₅₀ for this mixture was 188 mg/litre (Battersby, 1990b).

The EEC-activated sludge respiration inhibition test was also
used to determine the effect of cis-1,3-dichloropropene (94.5-
97.5% cis-, 1.5% trans-isomer and 0.25% 1,2-dichloropropane) on
the respiration rate of activated sludge. The EC₅₀ for the cis-
1,3-dichloropropene was 279 mg/litre (Battersby, 1990c).

Biodehalogenation by soil organisms has been demonstrated for
1,3-dichloropropene. The fumigant appeared to be chemically
hydrolysed to 3-chloroallyl alcohol and then converted to 3-
chloroacrylic acid. The chlorine is removed and the intermediate
products are converted to carbon dioxide and water. The rate of
disappearance of 1,3-dichloropropene at 15-20 °C was 2-3.5% per day
in sandy soil and up to 25% per day in clay soils. The chloroallyl
alcohol disappeared at rates of 20-60% per day at 15 °C (Van Dijk,
1974). Leistra et al. (1991) incubated 1,3-dichloropropene and its
transformation product 3-chloroallyl alcohol in water-saturated
subsoil material at 10 °C. The times for 50% and 95% transformation
ranged from 15 to 47 days and from 27 to 79 days, respectively, for
1,3-dichloropropene. The corresponding 50% and 95% transformation
times for 3 chloroallyl alcohol were 0.8-4.2 and 4.0-6.5 days,
respectively.

Chemical hydrolysis is the first step in the transformation of
1,3-dichloropropene. Further transformation is thought to result
from microbial action; 3-chloroacrolein and 3-chloroacrylic acid
have been isolated from the metabolism of 3-chloroallyl alcohol by
Pseudomonas species (see Fig. 4) (Belser & Castro, 1971; Roberts &
Stoydin, 1976).

Soil culture studies using media enriched with 1,3-
dichloropropenes, 1,2-dichloropropane, and "Mix D/D" at
concentrations of up to 100 mg/kg, produced abundant growth of all
microorganisms tested, indicating the use of the fumigants as carbon
sources. Several of these organisms (Rhizobium leguminosarum,
Bacillus subtilis, Arthrobacter globiformis, and Pseudomonas
fluorescens) produced greater amounts of amino acids (Altman &
Lawlor, 1966; Altman, 1969). The cis- and trans-isomers of 1,3-
dichloropropene have undergone biodehalogenation by a Pseudomonas
sp. isolated from the soil. Cis- and trans-1,3-dichloropropene
can be chemically hydrolysed in moist soils to the corresponding 3-
chloroallyl alcohols, which can be metabolized to carbon dioxide and
water by Pseudomonas sp. (Fig. 4).

The degradation of Telone II (92% 1,3-dichloropropene cis-
and trans-isomers; 2% 1,2-dichloropropane and 5% mixture of
propenes and hexenes, and 1% epichlorohydrin) in soil was studied
using ¹⁴C-1,3-dichloropropene in Fuquay loamy sand samples
collected from a field in Florida. The samples were collected
before, and one, and two weeks, and 2 years following application at
a rate of 15 kg/ha, at depths of 0-36 cm or 36-65 cm. After 28 days
incubation of ¹⁴C-1,3-dichloropropene in the soil, it was degraded
into ¹⁴CO₂ (44%), water-soluble metabolites (probably 3-
chloroallyl alcohol), bound residues, and possibly some microbial
mass. Little or no difference was observed in the degradation of
¹⁴C-1,3-dichloropropene in soil samples collected one week prior
to the field application of Telone II, or two weeks and two years
after application. A mixed bacteria culture isolated from the soil
in the presence of a carbon source, completely degraded ¹⁴C-1,3-
dichloropropene into ¹⁴CO₂, water-soluble products and microbial
mass (Ou, 1989).

4.4.1 Miscellaneous

Laboratory experiments were conducted to determine the effects
of 1,3-dichloropropene on the activity of invertase in a sandy soil.
The rates of application were 30 and 60 mg/kg. No inhibition was
found. The same dose levels were used to test the influence of the
compound on amylase in sandy soil. After 3 days, stimulation of the
formation of glucose from the added starch was seen, especially at
the lowest dose level. Microbial respiration was also tested in
sandy loam. The treatment did not significantly decrease oxygen
consumption (Tu, 1988).

5. ENVIRONMENTAL LEVELS AND HUMAN EXPOSURE

5.1 Air

Telone II, at a rate of 293 litre/ha, was applied, at a depth
of 0.45 m, simultaneously with pineapple crown planting. Each row of
pineapple was covered with black polyethylene film at the time of
planting. Air samples were taken inside the cover and at ground
level, 10, 20, 22, 27, and 30 days after fumigation. The
concentration inside the cover remained steady, at least until day
9; thereafter, a decrease was noticed and, after 22 days, the
substance was no longer detectable. At ground level, the
concentration fell gradually and was non-detectable after 30 days
(Albrecht & Chenchin, 1985).

A small-scale, field study was undertaken in 1986, when air
concentrations of 1,3-dichloropropene were measured in the vicinity
of ground treated with D-D 92 (93.8%), by hand injector at a dose
rate of 330 kg/ha. The air was monitored for 2 weeks. The
concentration of 1,3-dichloropropene varied between 0.004 and 0.88
mg/m³ during the first week. Levels of 1,3-dichloropropene in the
second week were below the limit of determination (0.002 mg/m³)
(Sherren & Woodbridge, 1987a).

5.2 Water

An investigation of 1,3-dichloropropene in well-water in
California was carried out by Maddy et al. (1982). Fifty-four wells
were selected in locations of high nematocide use. No samples showed
levels above the limit of determination of 0.1 µg/litre. In a
survey, 72 water samples from wells in California were analysed for
1,3-dichloropropene, but no samples contained levels above 1
µg/litre (limit of determination) (Peoples et al., 1980).

Connors et al. (1990) analysed potable water samples collected
in 8 homes in 3 communities in Connecticut and did not find 1,3-
dichloropropene (< 0.1 µg/litre).

Dowty et al. (1975) conducted a survey on drinking-water in New
Orleans, they found 1,3-dichloropropene, but did not give actual
levels or frequency of occurrence.

No 1,3-dichloropropene (limit of determination 1 µg/litre) was
found in 30 Canadian potable water facilities (Otson et al., 1982).

Apparently, chlorination of organic materials in water may lead
to traces of 1,3-dichloropropene (< 1 µg/litre). Therefore, this
process may be responsible for the observed presence of the
substance in tap water (Otson et al., 1982; Krijgsheld & Van der
Gen, 1986).

1,3-Dichloropropene has been identified in the waste water from
a textile plant. A level of 2 µg cis-isomer/litre was measured in
the influent of the waste water treatment plant, while higher
concentrations of cis-1,3-dichloropropene (e.g., 6 µg/litre) were
found in the effluent, together with the trans-isomer (0.9-4
µg/litre). Similarly, no 1,3-dichloropropene was detected in the
influent of a municipal waste treatment plant, but, after "super-
chlorination", a mean concentration of approximately 10 µg/litre
could be detected in the liquid sludge (Krijgsheld & Van der Gen,
1986).

Hallberg (1989) reported studies on the presence of pesticides
in groundwater in different States of the USA. 1,3-Dichloropropene
was found only in Oregon, but no concentration(s) were reported.

Van Beek et al. (1988) examined 33 groundwater wells up to a
depth of 50 m in the northern Netherlands for the presence of 1,3-
dichloropropene. In this area, "MIX D/D" had been used on a large
scale as a nematocide in potato growing since 1967. 1,2-
Dichloropropane was present in the groundwater, but no 1,3-
dichloropropene (> 0.1 µg/litre) was found in 45 samples from these
wells.

Samples of upper groundwater (from 1-2 m below the water level)
below 4 sandy soils were analysed in the Netherlands, for 2.5 years
in 8 sampling rounds. 1,3-Dichloropropene was detected in the
groundwater in 6/34 samples at concentrations in the range of
< 0.1-80 µg/litre. These observations were made below fields with
potato, maize, and bulb flower crops, all on low-humic to moderately
humic sandy soils (Loch & Verdam, 1989).

Lagas et al. (1989) analysed groundwater (up to 6 m depth) in 5
areas (4 of which are described by Loch & Verdam, 1989), and found
1,3-dichloropropene levels above the limit of detection (0.1
µg/litre) in 2 out of 22 samples (range: < 0.1-0.2 µg/litre) taken
from underneath potato crops and in 1 out of 8 samples (< 0.1-2.5
µg/litre) from below maize and bulb crops.

On 5 sites in a polder in the Netherlands, samples of surface
water were taken monthly in 1987-88 and analysed. The area is
situated next to the dunes (where groundwater is being pumped up for
the preparation of drinking-water), and is extensively used for
bulb-culture. The maximum concentration found for 1,3-
dichloropropenes ( cis- and trans-) was 2.5 µg/litre (Greve et
al., 1989).

In the Netherlands and the Federal Republic of Germany, 1,3-
dichloropropene was found in areas with extensive agriculture and
horticulture. 1,3-Dichloropropene was found in the upper groundwater
(depth 1-5 m) and the average levels ranged from 0.6 to 2530

µg/litre (maximum level 8620 µg/litre). In bores for irrigation (11-
24 m depth), an average of 0.23 (< 0.02-0.89) µg/litre was found
(Leistra & Boesten, 1989).

Ahlsdorf et al. (1989) determined the presence of 1,3-
dichloropropene in the upper groundwater of an area used for potato
growing, which was treated with this nematocide (about 140 kg/ha) in
1984. Very low levels of 1,3-dichloropropene (1-4 µg/litre) were
found in soil with a high organic matter content, but concentrations
of up to 8620 µg/litre were found in the groundwater of a clay
podsol soil containing a high sand content, after one month.

1,3-Dichloropropene was detected in irrigation wells that were
close to a piece of land that was treated with the chemical (10-25 m
distance) in Schleswig Holstein (Germany). In the well water,
concentrations of 1,3-dichloropropene varied between 0.06 and 0.89
µg/litre (Rexilius & Schmidt, 1982).

5.3 Crops

Residues in edible crop commodities, arising from the use of
1,3-dichloropropene or "MIX D/D", are reported to be generally below
the limit of detection. The obvious reason for this, is the fact
that crops are not normally planted until most of the product
applied has dissipated. Another reason is that any 1,3-
dichloropropene or "MIX D/D" taken up by the plant, would have to
survive the whole crop cycle to be detected in the harvest
commodity.

Supervised trials with "MIX D/D", with 23 crops in 8 countries
showed that residues in edible crop commodities were below the
limits of determination (< 0.01 mg/kg), for 1,3-dichloropropene,
1,2-dichloropropane, and 3-chloroallyl alcohol.

5.4 Occupational exposure

Albrecht (1987) carried out a survey to assess the exposure of
72 workers on a Hawaiian pineapple farm (attendants, crown
unloaders, (truck) drivers, irrigation workers, supervisors, mulch
coverers, and planters). Exposures were predominantly below 4.54
mg/m³ (1 ppm). The concentrations in these workers ranged between
0.032 and 4.626 mg/m³ (0.007-1.019 ppm).

Brouwer et al. (1991a) studied the inhalation of cis- and
trans-1,3-dichloropropene in 12 commercial applicators in the
Netherlands. The time-weighted average (TWA) concentrations of 1,3-
dichloropropene ranged from 1.9 to 18.9 mg/m³. Short-term exposure
levels during tank-loading and repair ranged up to 30 mg/m³. No
correlation was observed between exposure and total area injected
with 1,3-dichloropropene. Emission of 1,3-dichloropropene vapour

from the soil or from spilled liquid dripping from the nozzles on to
the soil may contribute to exposure.

An employee air-monitoring study to determine the amount of
Telone II to which personnel would be exposed, removing soil core
samples in the immediate area of the drilling, was carried out. The
concentration in the air was between 0.0982 and 1.79 mg/m³ on the
first day, and between 0.202 and 3.056 mg/m³ on second day. The
time-weighted averages from personal monitoring on days one and two
were 0.65 and 0.90 mg/m³, respectively. The time-weighted averages
from air monitoring on days one and two were 0.39 and 0.59 mg/m³
(Fong & Maykoski, 1985).

A study on a single operator during a one-day application was
carried out in the Federal Republic of Germany in 1986. Short-term
inhalation exposures to 1,3-dichloropropene were observed during the
filling operation (5.6-16.3 mg/m³) and during nozzle changing
(18.3 mg/m³). The overall exposure during 11 h exceeded the
recommended TWA value (Eadsforth et al., 1987).

An air monitoring study on exposure to 1,3-dichloropropene
during the application of "Mix D/D" (not less than 50%) and D-D 92
(not less than 92%) was carried out at different locations near
Nimes in France in 1988. The 8-h time-weighted average (TWA) air
concentrations of total 1,3-dichloropropene for the applicator on
the 2 days of application were 11.3 and 13.2 mg/m³, respectively,
and for the tractor driver on the second day, 14.4 mg/m³.
Relatively high, short-term inhalation exposures of the applicator
were measured during filling operations; the concentrations varied
between 6.4 and 83.5 mg/m³. These short-term exposures were found
to contribute significantly to the overall time-weighted average
exposures over the working period (Rocchi & van Sittert, 1989).

Albrecht & Chenchin (1985) found measurable concentrations of
1,3-dichloropropene in the range of 2.4-18.5 mg/m³ during a 8-h
shift in 8 out of 15 workers, planting pineapple crowns by hand,
simultaneously with 1,3-dichloropropene (Telone II) treatment of the
soil at 293 litre/ha.

6. KINETICS AND METABOLISM

6.1 Absorption, distribution, and elimination

6.1.1 Oral

6.1.1.1 Rat

Groups of 6 adult male and 6 female Carworth Farm E rats
received, by stomach tube, 2.5-2.7 mg cis-1,3-dichloro-[2-
¹⁴C]propene or trans-1,3-dichloro-[2-¹⁴C]propene in 0.5 ml
arachis oil per rat, and excretion was followed. After 4 days, the
animals were killed and the radioactivity measured in skin and
carcasses. The excretion of radioactivity was very rapid, 80-90% was
eliminated in the faeces, urine, and expired air in the first 24 h.
The urine was the major route of elimination, i.e., 80.7 and 56.5%
(average of males and females) of the dose for cis- and trans-
1,3-dichloropropene, respectively. Only 2.6 and 2.2% of the 2
isomers, respectively, were eliminated in the faeces in 4 days,
while 3.9 and 23.5%, respectively, were eliminated as ¹⁴CO₂ in 4
days in the expired air. Levels of the other volatile compounds in
air were only 1-3% of the dose. Up to 1% of the dose in the skin and
carcass was found. The difference in the amount of labelled CO₂ in
expired air and urine indicated a difference in the kinetics of the
2 isomers (Hutson et al., 1971).

Groups of 8 adult Fischer 344 rats/sex were given non
radiolabelled 1,3-dichloropropene at 5 mg/kg body weight, in corn
oil, by gavage, for 14 consecutive days, prior to a single dose of 5
mg ¹⁴C-1,3-dichloropropene/kg body weight (actual 4.5 mg)
(uniformly labelled) (96.3%; 53.3% cis- and 43.0% trans-),
administered to 5 out of the 8 rats on day 15. The remaining 3
rats/sex were sacrificed. The distribution of radioactivity found in
the tissues (4-6%) of repeatedly dosed rats, 48 h after dosing, was
similar to that of single dosed animals. There was no sex difference
in the distribution of the radioactivity. In addition to the
repeatedly dosed rats, 2 rats of each sex, which had not been
previously dosed, received a single gavage dose of 5 mg ¹⁴C-1,3-
dichloropropene/kg body weight. The urine was the major route of
elimination of the radioactivity derived from ¹⁴C-1,3-
dichloropropene, which ranged from 60 to 65% of the administered
dose in 48 h in the rats with repeated doses and a single dose.
Elimination of 1,3-dichloropropene as ¹⁴CO₂ was approximately
(average) 26% of the administrated radioactivity with about 4-5% of
the dose eliminated in the faeces, for all groups (Waechter & Kastl,
1988).

In another study, the fate of ¹⁴C- cis- and ¹⁴C- trans-
1,3-dichloropropene (97%; 62% cis and 38% trans) was determined
after a single oral dose of 1 or 50 mg/kg body weight to male

Fischer 344 rats (3 animals per dose level). Urine, faeces, expired
air, tissues, and remaining carcasses were analysed after 48 h.
Urine was the major route of excretion, 51-61% of the administered
dose being excreted over 48 h. In the carcass, 6% of the dose was
found at the end of 48 h. On the basis of interval excretion data,
half-lives for urinary excretion ranged from 5 to 6 h. Faeces and
expired CO₂ accounted for roughly 18% and 6%, respectively. The
tissue concentrations of ¹⁴C activity were highest in the stomach
wall, followed in decreasing order by kidneys, liver, bladder, skin,
and fat (Dietz et al., 1984a,b, 1985).

6.1.1.2 Mouse

The fate of ¹⁴C- cis- and ¹⁴C- trans-1,3-dichloropropene
(97%; 62% cis and 38% trans) was studied after oral dosing of
male B₆C₃F₁ mice with 1 or 100 mg/kg body weight (3
animals/dose level). Urine, faeces, expired air, tissues, and
remaining carcasses were analysed after 48 h. Urine was the major
route of excretion, with 63 and 79%, respectively, of the
administered doses (1 and 100 mg/kg body weight) being excreted over
48 h. Half-lives for urinary excretion ranged from 5 to 6 h. Faeces
and expired CO₂ accounted for 15 and 14% of the ¹⁴C-
radioactivity, respectively. In the carcass, 2% was found. The
tissue concentrations of ¹⁴C-activity were highest in the stomach
wall, followed in decreasing order by kidneys, liver, bladder, fat,
and skin (Dietz et al., 1984a,b, 1985).

6.1.2 Inhalation

6.1.2.1 Rat

Stott & Kastl (1985, 1986) studied the pharmacokinetics of the
uptake of vapours of technical grade 1,3-dichloropropene (49.3%
cis- and 42.8% trans-isomer) and the disappearance of cis- and
trans-1,3-dichloropropene from the blood in groups of 3-6 male
Fischer 344 rats exposed to actual concentrations of 136, 409, 1362,
and 4086 mg/m³ for 3 h.

The uptake of 1,3-dichloropropene did not increase
proportionately with increasing exposure concentration due to an
exposure level-related decrease in the respiration rate and
respiration min/volume of rats exposed to > 409 mg 1,3-
dichloropropene/m³ and the saturation of metabolism of 1,3-
dichloropropene in rats exposed to > 1362 mg/m³. Absorption of
inhaled 1,3-dichloropropene occurred via the lungs, primarily in the
lower respiratory tract (approximately 50% of total inhaled), with a
small amount via the nasal mucosa (11-16%).

Following exposure to < 1362 mg/m³, both isomers were
rapidly eliminated from the blood, with a half-life of 3-6 min.

There was no interaction in the kinetics of both isomers. In
addition, data obtained on rats exposed to 1362 mg/m³ revealed
that this rapid elimination phase was followed by a slower
elimination phase having a half-life of 33-43 min. These data
demonstrated that a combination of saturable metabolism and
chemically-induced changes in respiration control 1,3-
dichloropropene uptake and body-burden in rats. However, only
decreases in respiration appear to influence vapour uptake.

Fisher & Kilgore (1988a) studied the excretion of the
mercapturic acid of cis-dichloropropene in Sprague-Dawley rats. In
a nose-only exposure system, groups of 3 rats were exposed for 1 h
to Telone II (94%) at average concentrations of 0, 181.6, 485.8,
1289.4, 1806.9, or 3582.1 mg/m³. Urine samples (24 h) were
collected and analysed for the mercapturic derivative of cis-
dichloropropene. At the lower exposure levels (< 1289.4 mg/m³),
urinary excretion of the mercapturic acid derivative increased with
exposure level. With exposure to 1806.9 or 3582.1 mg/m³, no
further increase was found, suggesting saturation of the metabolic
process.

6.2 Influence on tissue levels of glutathione

6.2.1 Oral

Oral administration of 1,3-dichloropropene to rats or mice
resulted in significant, dose-related reductions in the levels of
non-protein sulfhydryls (NPS) (indicator of tissue glutathione
concentration) in the forestomach and to a lesser extent in the
glandular stomach and liver (Dietz et al., 1984b, 1985, see also
section 6.4).

6.2.2 Inhalation

Shortly after inhalation exposure of rats to cis-1,3-
dichloropropene, kidney and liver NPS contents were reduced in a
dose-related manner, but returned to control values 18 h after
exposure. Lung NPS levels were not affected (Stott & Kastl, 1986,
see section 6.1.2.1; Nitschke & Lomax, 1990, see section 8.2.2.2).

Male Sprague-Dawley rats (200-250 g) were exposed through
inhalation to 1,3-dichloropropene (Telone II, 94%) concentrations of
0, 9.1, 22.7, 150, 1384.7, 3504.9, 4335.7, or 7790.6 mg/m³ to
assess the relationship between 1,3-dichloropropene exposure
concentration and tissue levels of reduced glutathione (GSH).
Animals were exposed for 1 h in a dynamic, nose-only system. GSH
contents were measured in the heart, kidneys, liver, lung, nasal
mucosa, and testes, 2 h after 1,3-dichloropropene exposure. A
decrease in nasal GSH, first seen at 22.7 mg/m³, followed an
exposure concentration-dependent curve. Exposure to concentrations

above 150 mg/m³ reduced the level of liver GSH. Lung GSH remained
relatively constant at 75% of control concentrations up to 4335.7
mg/m³. Significantly decreased GSH levels were observed in the
heart, liver, lung, and testes at 7790.6 mg/m³. Kidney GSH content
was not significantly decreased. Unchanged 1,3-dichloropropene was
not present in the blood of animals 2 h after exposure to 4335.7
mg/m³ or less. Serum lactic dehydrogenase activity was affected
only at 7790.6 mg/m³. Lung weight, measured 2 and 6 h after
exposure, did not differ from controls for any exposure level
(Fisher & Kilgore, 1988b).

Four male Sprague-Dawley rats (200-250 g) were exposed to
Telone II (94%) for 1 h, in a dynamic, nose-only exposure system.
The actual 1,3-dichloropropene concentration was 354.1 ± 49.9, 703.7
± 408.6, and 1834.2 ± 113.5 mg/m³ (relative concentrations of
cis- and trans-isomers were approximately 62 and 38%,
respectively). The GSH conjugation of 1,3-dichloropropene (GSCP) in
the blood of rats following exposure showed that there was no
significant difference between the regression line expressed as
either monophasic or biphasic decay at any exposure concentration.
Moreover, no differences were found in the regression lines between
the exposure concentrations. The elimination half-time of GSCP was
approximately 17 h following exposure to 354.1, 703.7, or 1834.2
mg/m³, and, thus, was not dose-dependent. This fits a one-
compartment model (Fischer & Kilgore, 1989).

6.3 Biotransformation

6.3.1 Rat

In urine from rats and mice treated orally with ¹⁴C-
dichloropropene, no unchanged parent compound, but 2 major and 2
minor metabolites were found. The predominant metabolite was N-
acetyl- S-(3-chloroprop-2-enyl) cysteine with its sulfoxide or
sulfone. These data indicate that conjugation with glutathione is a
major route of 1,3-dichloropropene metabolism in the rat (Dietz et
al., 1984a,b, 1985) (see Fig. 4 and section 6.1.1).

Although the spontaneous reaction of cis-1,3-dichloropropene
with glutathione is slow in the rat, the rapid urinary excretion is
due to hepatic glutathione transferase, which catalyses its
conjugation with glutathione. The transferase is present in the rat
liver cytosol fraction and little microsomally mediated metabolism
occurs. The cis-isomer is a better substrate than the trans-
isomer for glutathione transferase. The conjugation then follows a
classic mercapturic acid pathway (Boyland & Chasseaud, 1969). The
conjugated product N-acetyl- S-(3-chloroprop-2-enyl) cysteine and
its sulfoxide are excreted in the urine of rats and mice (Climie et
al., 1979; Dietz et al., 1984b; van Sittert, 1984, 1989).

It has been shown that a minor metabolic pathway of the cis-
1,3-dichloropropene is mono-oxygenase catalysed oxygenation, leading
to the possible formation of the metabolite cis-1,3-
dichloropropene-oxide (II in Fig. 5) (Van Sittert, 1989).

Rats administered 25-450 µg cis- and trans-1,3-
dichloropropene/kg body weight, intraperitoneally, showed excretion
of N-acetyl- S-( cis- and trans-3-chloroprop-2-enyl)-L-
cysteine for 55% (cis-) and 45% (trans-) of the dose within 24 h
(Onkenhout et al., 1986).

In the study of Waechter & Kastl (1988) (see section 6.1.1.1),
in which rats were administered daily doses of 5 mg of non-labelled
1,3-dichloropropene/kg body weight followed by a single dose of 5 mg
¹⁴-C (uniformly) labelled 1,3-dichloropropene, or a single dose of
5 mg/kg body weight, the major urinary metabolites were the
mercapturic acid of 1,3-dichloropropene (1,3-D-MA) and its
sulfoxide. The repeatedly dosed rats excreted slightly higher
percentages of the dose as mercapturic acids than the single dosed
rats (28.5% vs 22.7% for males and 25.5% vs 14.3% for females). The
isomeric ratio of the 2,3-D-MA was approximately 80% cis- and 20%
trans- for all groups.

6.3.2 Humans

Van Welie et al. (1989, 1991) determined the relationship
between respiratory occupational exposure to cis- and trans-1,3-
dichloropropene and urinary excretion of 2 mercapturic acid
metabolites, N-acetyl- S-( cis- and trans-)-3-chloroprop-2-
enyl)-L-cysteine ( cis- and trans-DCP-MA) by 12, 1,3-
dichloropropene applicators in the Netherlands. Urinary excretion of
these mercapturic acids followed first-order elimination kinetics.
Urinary half-lives of elimination were 5.0 ± 1.2 h for the cis-
mercapturic acid and 4.7 ± 1.3 h for the transform. These values
were not statistically significantly different. A clear correlation
was observed between the 8-h time-weighted average (TWA) exposure to
cis- and trans-1,3-dichloropropene and complete cumulative
urinary excretion of cis- and trans-DCP-MA. The cis-DCP-MA
yielded 3 times more mercapturic acid (45%) than the trans- form
(14%), probably because of differences in kinetics. It was concluded
that the uptake of cis- and trans-1,3-dichloropropene, their
metabolism to the corresponding mercapturic acids, and urinary
excretion was a rapid process.

In California, applicators of 1,3-dichloropropene were also
studied for personal air exposure and urinary excretion of
mercapturic acid metabolites. The amount excreted was correlated
with the product of the duration of exposure x TWA. The highest
urinary metabolite concentration occurred during the application
period, indicating rapid excretion. Skin absorption of vapour was
not a significant route of exposure (Osterloh et al., 1984, 1989,
see also section 9.2.1).

Air and biological monitoring of 6 operators exposed to "Mix
DD" soil fumigant during filling operations in the Netherlands was
carried out in 1985-86. There was rapid metabolism and elimination:
the half-lives of mercapturic acid excretion were 4-5 h, with a
return to background levels after 24 h. It was calculated that,
under linear, non-saturation conditions, approximately 23% of the
inhalation dose of the cis-isomer and 10% of the trans-isomer
are excreted in the urine as mercapturic acids (Eadsforth, 1987).

6.4 Reaction with macromolecules

6.4.1 Mouse

The non-protein sulfhydryl (NPS) content, e.g., GSH, and
covalent binding to macromolecules were determined in the tissues of
male B₆C₃F₁ mice. Single oral doses of 0, 1, 5, 25, 50, or 100
mg 1,3-dichloropropene 97% ( cis- 62% : trans-isomer 38%)/kg body
weight were given for NPS studies and 0, 1, 50, or 100 mg ¹⁴C-1,3-
dichloropropene/kg body weight for binding studies. Non-glandular
forestomach, glandular stomach, liver, kidneys, and bladder were
analysed, 2 h after dosing. Although NPS depletion and dose-related
increases in macromolecular binding were noted in several tissues of
rats, these effects were more pronounced in the non-glandular
stomach than in any other tissue (including glandular stomach,
liver, kidneys, and bladder). The no-observed-effect level (NOEL)
for NPS depletion in rat non-glandular stomach was 1 mg/kg body
weight. NPS levels in non-glandular forestomach were significantly
decreased at doses of 25 mg or higher and, in the liver, at 100
mg/kg body weight. Binding in the non-glandular forestomach was
greatest at dose levels that caused the most depletion of tissue
NPS. Limited binding occurred in the liver, kidneys, and bladder
(Dietz et al., 1984b, 1985).

6.4.2 Rat

Groups of 3-9 male Fischer 344 rats (200-260 g) were
administered 50 mg cis-1,3-dichloropropene (94.1% cis- and 2.5%
trans-) or 50 mg trans-1,3-dichloropropene (97.3% trans- and
0.8 cis-)/kg body weight, by gavage. The rats were sacrificed at
various intervals after dosing, to determine the tissue non-protein
sulfhydryls (NPS) in the liver, kidneys, forestomach, glandular

stomach, and bladder. Blood samples were also taken to determine the
presence of unchanged 1,3-dichloropropene. Cis-1,3-dichloropropene
was only detected in the blood (6.58 µg/litre) 15 min after dosing,
the blood levels of trans-1,3-dichloropropene were 11.72 and 8.38
µg/litre, respectively, 15 and 45 min after dosing. A statistically
significant decrease in the non-protein sulfhydryl contents of the
liver, kidneys, forestomach, and glandular stomach was found. This
depletion reached a maximum, approximately 2-h after dosing. No
depletion was noted in the bladder. It is not possible to
distinguish the effects of cis- and trans-1,3-dichloropropene on
NPS, as the results for the individual isomers were not reported.
The results indicated that orally administered 1,3-dichloropropene
produces a rapid and significant depletion of tissue non-protein
sulfhydryls in the rat (Dietz et al., 1982).

The non-protein sulfhydryl (NPS) contents and covalent binding
to macromolecules were determined in the tissues of male Fischer 344
rats. Single, oral doses of 0, 1, 5, 25, 50, or 100 mg 1,3-
dichloropropene 97% ( cis-62% and trans-isomer 38%) were given
for NPS studies and 0, 1, 50, or 100 mg ¹⁴C-1,3-di