WORLD HEALTH ORGANIZATION FOOD AND AGRICULTURE
ORGANISATION MONDIALE DE LA SANTE ORGANISATION POUR L'ALIMENTATION
DATA SHEETS ON PESTICIDES No. 64
It must be noted that the issue of a Data Sheet for a
particular pesticide does not imply endorsement of the pesticide by
WHO or FAO for any particular use, or exclude its use for other
purposes not stated. While the information provided is believed to
be accurate according to data available at the time when the sheet
was compiled, neither WHO nor FAO are responsible for any errors or
omissions, or any consequences therefrom.
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Food and Agriculture des Nations Unies pour
Organization of the United l'Alimentation et l'Agriculture
Nations or of the World Health ou de l'Organisation Mondiale de
Organization. la Santé.
Primary Use: Molluscicide
Chemical Group: Morpholine derivative
1. GENERAL INFORMATION
1.1 COMMON NAME
Trifenmorph (ISO, BSI, exception - France (triphenomorphe))
IUPAC and CAS: 4-(triphenylmethyl)-morpholine)
CAS Reg. No.: 1420-06-0
Molecular formula: C23H23NO
Molecular weight: 329.4
FresconR; n-tritylmorpholine; WL 8008R; Trifenmorph;
Trifenmorph is a highly selective neurotoxin to aquatic and
semi-aquatic snails. It is virtually harmless to terrestrial
molluscs, insects and terrestrial vertebrates; slightly toxic to
some fish; and, readily metabolized to less toxic compounds. It has
no residual action and is not adsorbed by mud or vegetation. It is
readily metabolized to less toxic compounds in mammals.
1.3 SELECTED PROPERTIES
1.3.1 Physical characteristics
Trifenmorph is a white (colourless) crystalline solid. It melts
at 176-178°C then resolidifies, its second melting point is 185-
187°C. The technical material is 90-95% pure, melting first at 150-
170°C and again at 170-185°C. It is not corrosive.
In water, 0.02 mg/l at 20°C; in carbon tetrachloride, 300 mg/l;
in chloroform, 450 g/l; in tetrachloroethylene, 225 g/l.
Trifenmorph is heat stable and also in alkaline media, in mild
acid media it is hydrolysed to morpholine and triphenylmethanol. It
decomposes slightly in U.V. light.
1.3.4 Vapour pressure
1.87 x 10-8 kPa (1.4 x 10-7 mmHg) at 20°C.
1.4 AGRICULTURE, HORTICULTURE AND FORESTRY
1.4.1 Common formulations
Trifenmorph is available only in emulsifiable concentrate form,
165 g a.i./l.
1.4.2 Pests controlled
Trifenmorph is active against aquatic and semi-aquatic snails
1.4.3 Use pattern
Trifenmorph may be applied to irrigation ditches and other
moving water systems by drip-feed technique at 0.03-0.10 mg/l and,
to static water at approximately 0.1-1.0 mg/l. To wet terrain it may
be applied at a rate of 500 g/ha.
1.4.4 Unintended effects
Trifenmorph is not known to be toxic to plants and insects and
it is only slightly toxic to vertebrates. It is a moderate to high
acute hazard to fish, depending upon the species and prevailing
1.5 PUBLIC HEALTH USE
As in 1.4 for control of disease vector snails (e.g. Lymnaea
truncatula for control of fasicioliasis).
1.6 HOUSEHOLD USE
No recommended use.
2. TOXICOLOGY AND RISKS
2.1 TOXICOLOGY - MAMMALS
2.1.1 Absorption route
Trifenmorph may be absorbed from the gastrointestinal tract and
through the intact skin. See 2.1.3 below.
2.1.2 Mode of action
In the target organism, trifenmorph increases intracellular
chloride levels in neurons, most probably through alteration of the
bicarbonate-chloride shift mechanism. By this means the balance
between excitatory and inhibitory threshold in neurons is altered
and the entire nervous system is disrupted.
2.1.3 Excretion products
In dogs, rats and mice it was rapidly metabolized by
gastrointestinal enzymes to triphenylcarbinol, and morpholine.
Triphenylcarbinol was absorbed slowly and it was oxidised by hepatic
systems to para-hydroxyphenyldiphenylcarbinol and also, ortho- and
meta-hydroxytriphenylcarbinols to a lesser extent. Morpholine was
rapidly absorbed and excreted in the urine unchanged as a glucuronic
acid conjugate. Triphenylcarbinol and its hydroxy derivatives were
found in urine and faeces as free compounds and in three glucuronide
fractions; diglucuronides, carbinol-group glucuronide and phenolic-
groups glucuronides. In 14C-labelled tracer dose studies on 14CO2
was respired and, after 96 hours only 3% of the radioactivity
remained in the carcass.
2.1.4 Toxicity, single dose
Rat 100-200 mg/kg; in chlorinated solvents
Rat 1200-1600 mg/kg; in organic solvents
Mouse 700-4800 mg/kg
The oral toxic dose is dependent upon the vehicle. Chlorinated
solvents reduce the toxic dose, suggesting a synergistic effect.
Rat 1000 mg/kg bw
2.1.5 Toxicity, repeated doses:
Oral: See section 2.1.6 - Dietary studies.
Cumulation of compound - Trifenmorph is unlikely to be
accumulative since it is readily metabolized and excreted.
2.1.6 Dietary studies
Short term - In a 90 day feeding study the no-effect level
for rats was estimated be 100 mg/kg bw.
Long term - No information available.
2.1.7 Supplementary studies of toxicity
Mutagenicity: Trifenmorph was not mutagenically active in
amicrobial Ames test.
Teratology: No information available.
Reproduction: No information available.
Neurotoxicity: No information available.
2.1.8 Modification of toxicity
Chlorinated solvents appeared to behave as synergists in rat
acute oral toxicity tests.
2.2 TOXICOLOGY - MAN
2.2.1 Absorption route
Trifenmorph may be absorbed from the gastrointestinal tract.
However, in mammalian studies it has been found to be extensively
metabolized in gut leaving the primary metabolites to be absorbed.
It may also be absorbed to a limited extent through the intact skin.
2.2.2 Dangerous doses
The toxicity of Trifenmorph to man has not been sufficiently
studied to predict dangerous doses.
2.2.3 Observations of occupationally exposed workers
No information available.
2.2.4 Observation on exposure of the general population
No information available.
2.2.5 Observation of volunteers
No information available.
2.2.6 Reported mishaps
No information available.
2.3 TOXICITY TO NON-MAMMALIAN SPECIES
( Barbus and Tilapia spp.) survived a 10-day exposure to
Rainbow trout 0.20 (mg/l) 24 hr; 16.5% E.C.
Rainbow trout 0.17 (mg/l) 48 hr; 16.5% E.C.
Rainbow trout 0.094 (mg/l) 24 hr; 50% paste
Rainbow trout 0.078 (mg/l) 48 hr; 50% paste
Rainbow trout 0.33 (mg/l) 24 hr; 16.5% E.C.
Rainbow trout 0.28 (mg/l) 48 hr; 16.5% E.C.
Rainbow trout 0.10 (mg/l) 96 hr; 16.5% E.C.
Rainbow trout 0.74 (mg/l) 24 hr; 16.5% E.C. in hard water
Rainbow trout 0.62 (mg/l) 48 hr; 16.5% E.C. in hard water
Rainbow trout 0.52 (mg/l) 96 hr; 16.5% E.C. in hard water
Rainbow trout 0.135 (mg/l) 24 hr; 50% paste
Rainbow trout 0.115 (mg/l) 48 hr; 50% paste
Rainbow trout 0.080 (mg/l) 96 hr; 50% paste
Rainbow trout 8.2 (mg/l) 24 hr; 50% paste in hard water
Rainbow trout 2.5 (mg/l) 48 hr; 50% paste in hard water
Rainbow trout 1.5 (mg/l) 96 hr; 50% paste in hard water
No information available.
2.3.3 Other species
Aquatic micro-flora and fauna are reported to be unaffected at
0.2 mg/l. Terrestrial organisms, including snails are not affected
3. FOR REGULATORY AUTHORITIES - RECOMMENDATIONS ON REGDLATION OF
3.1 RECOMMENDED RESTRICTIONS ON AVAILABILITY
(for definition of categories see introduction)
All available formulations, category 5
3.2 TRANSPORT AND STORAGE
Formulations in category 5 - Should be transported and stored
in early labelled, leakproof containers out of reach of children,
away from food and drink. Avoid contact with metals other than
aluminium and tin.
Formulations in category 5 - No facilities other than those
needed for the handling of any chemical are required.
3.4 DISPOSAL AND/OR DECONTAMINATION OF CONTAINERS
Formulations in category 5 - Containers may be decontaminated
(for method see paragraph 4.3 of part 4). Decontaminated containers
should not be used for any other purpose. Containers should be
burned or should be crushed and buried below topsoil. Care must be
taken to avoid subsequent contamination of water sources.
3.5 SELECTION, TRAINING AND MEDICAL SUPERVISION OF WORKERS
Formulations in category 5 - No pre-employment or periodic
medical examinations are required. Special account should be taken
of the workers' ability to comprehend and follow instructions.
Training of workers in techniques to avoid contact is essential.
3.6 ADDITIONAL REGULATIONS RECOMMENDED IF DISTRIBUTED BY AIRCRAFT
All formulations - Pilots and loaders should have special
training in application methods and recognition of early warning
symptoms of poisoning and, they must wear a suitable respirator.
Flagmen should wear overalls and a broad brimmed hat and be well
away from the dropping zone.
Formulations in category 5 - Minimum cautionary statement -
CAUTION - POISON
This product contains trifenmorph, a molluscicide of only
slight toxicity to mammals. It is a neurotoxic agent in Molluscs but
of unknown health hazard to humans. It may be absorbed by ingestion
and to a limited extent through the intact skin - avoid skin
contact. Wash with soap and water after handling. Keep out of reach
of children and well away from food, animal feed and food utensils.
If a large quantity is ingested call a physician. There is no
specific antidote, artificial resuscitation may be required.
3.8 RESIDUES IN FOOD
Maximum residue limits for trifenmorph have not yet been
recommended by the Joint FAO/WHO meeting on Pesticide Residues.
4. PREVENTION OF POISONING IN MAN AND EMERGENCY AID
4.1 PRECAUTIONS IN USE
Trifenmorph is molluscicide of only slight toxicity to mammals.
It is readily absorbed from the gastrointestinal tract and, to a
limited extent, through the intact skin. It is a neurotoxic agent to
the target organisms but of unknown health hazard to man.
4.1.2 Manufacture and formulation - T.L.V.
No information. Closed systems and forced ventilation may be
required to reduce, as much as possible, the exposure of workers to
4.1.3 Mixers and applicators
When opening a container and when mixing, protective
impermeable boots, clean overalls, impermeable gloves and a
respirator should be worn. Mixing, if not mechanical, should always
be carried out with a paddle of appropriate length. Avoid contact
with mouth and eyes. Before eating, drinking or smoking, hands and
other exposed skin should be thoroughly washed with alkaline soap.
4.1.4 Other associated workers (including flagmen in aerial
Persons exposed to trifenmorph and associated with its
application should observe the precautions described above in 4.1.3.
4.1.5 Other populations likely to be affected
With good agricultural practice, subject to 4.2 below, other
populations are unlikely to be exposed to hazardous amounts of
4.2 ENTRY OF PERSONS INTO TREATED AREAS
Unprotected persons may enter treated areas immediately after
spraying without being exposed to hazardous amounts of trifenmorph.
4.3 SAFE DISPOSAL OF CONTAINERS AND SPILLAGE
Residues in containers should be emptied in a diluted form into
a deep pit taking care to avoid ground waters. The empty container
may be decontaminated by rinsing two or three times with water and
detergent and scrubbing the sides. The hands should be protected
during this work. Decontaminated containers should not be used for
any other purpose.
4.4 EMERGENCY AID
4.4.1 Early symptoms of poisoning
Trifenmorph has apparently not caused human poisoning and has
not been studied in man for any other reason therefore the signs and
symptoms of poisoning are not known.
4.4.2 Treatment before person is seen by a physician, if symptoms
appear following exposure
The person should stop work immediately, remove contaminated
clothing and clean the affected skin area. First, soak-up any liquid
remaining on the skin with readily disposable material (e.g., talcum
powder or absorbent cloth or paper), wash the affected area with
warm water and alkaline soap. For eye contamination, wash with
copious amounts of water. Keep the person warm. If the material was
swallowed and signs of toxicity are severe, induce vomiting if
person is conscious and aspiration of vomit can be avoided. In the
event of collapse, apply artificial respiration, preferably by
5. FOR MEDICAL AND LABORATORY PERSONNEL
5.1 MEDICAL DIAGNOSIS AND TREATMENT OF POISONING
5.1.1 General information
Trifenmorph is a molluscicide: a neurotoxic agent in the target
organism but with unknown toxic effect in man. It may be absorbed by
ingestion, and through the intact skin to a limited extent.
Trifenmorph is a morpholine derivative which is readily metabolized
in the digestive tract to compounds of no known toxicity, morpholine
5.1.2 Signs and symptoms
No information is available on the acute toxic effects of
There are no established, practical methods for determining
primary metabolite levels in body fluids. Urinary levels of
morpholine and triphenylcarbinols may be a useful indication of
Follow treatment for general poisoning. Establish respirations
and create artificial airway if necessary. Check adequacy of tidal
volume. Treat hypotension with fluids or plasma - avoid vasopressors
if possible. Induce vomiting with syrup of Ipecac if a large,
potentially health threatening dose has been ingested. Save the
initial emesis for analysis. If emesis is contraindicated,
activated, charcoal absorption may be useful also cathartics such as
sodium or magnesium sulfate may be considered. If exposure is by
contact, thorough decontamination of exposed skin with soap and
water is essential. In case of eye exposure decontaminate with
copious amounts of water forced diuresis and dialysis may be
considered in those patients not responding to standard therapeutic
5.1.6 References to previously reported cases
There have been no previously reported cases.
5.2 SURVEILLANCE TESTS
5.3 LABORATORY METHODS
References only are given.
5.3.1 Detection and assay of compound and residues
K. I. Beynon & G. R. Thomas (1967), Bull. WHO, 37, p. 47.
K. I. Beynon & A. N. Wright (1975), Pestic. Sci., 6, p. 515.
5.3.2 Other tests in case of poisoning