Toxicological evaluation of some food
    additives including anticaking agents,
    antimicrobials, antioxidants, emulsifiers
    and thickening agents


    The evaluations contained in this publication
    were prepared by the Joint FAO/WHO Expert
    Committee on Food Additives which met in Geneva,
    25 June - 4 July 19731

    World Health Organization


    1    Seventeenth Report of the Joint FAO/WHO Expert Committee on
    Food Additives, Wld Hlth Org. techn. Rep. Ser., 1974, No. 539;
    FAO Nutrition Meetings Report Series, 1974, No. 53.



         These compounds have been evaluated for acceptable daily intake
    by the Joint FAO/WHO Expert Committee on Food Additives (see Annex 1,
    Refs No. 6, No. 7 and No. 13) in 1961, 1964 and 1965.

         Since the previous evaluation, additional data have become
    available and are summarized and discussed in the following monograph.
    The previously published monographs have been expanded and are
    reproduced in their entirety below.



         Sulfite is oxidized in the body to sulfate. Bisulfite reacts with
    aldehydes and ketones, including aldehydic sugars. This is a
    reversible reaction; the equilibrium concentrations depend on
    temperature. The acute effects of sulfite in foods are related to the
    amount and concentration of free sulfur dioxide and to the speed at
    which the additive compounds liberate the bound sulfur dioxide.
    Sulfite may also react reversibly with disulfide linkages in proteins.
    The disulfide is split into one part containing a thiol group and
    another part with an S-sulfonic acid group (Swan, 1957).

         Four rats given oral doses of sodium metabisulfite as a 0.2%
    solution eliminated 55% of the sulfur as sulfate in the urine within
    the first four hours (Bhagat & Lockett, 1960). A rapid and
    quantitative elimination of sulfites as sulfate was also observed in
    man and dog (Rost, 1933).

         Sulfite is a strong inhibitor of some dehydrogenases, e.g.
    lactate dehydrogenase (heart) and malate dehydrogenase; 50% inhibition
    by about 10-5M sulfite (Pfleiderer et al., 1956).

         Small amounts of sulfite are regularly formed in the intermediary
    metabolism of the body in the catabolism of cystine by the non-
    enzymatic decomposition of 8-sulfinyl pyruvic acid to pyruvic acid and
    SO2. The stationary concentration of sulfite in the cells is too
    small to be measured. However, 0.10-0.12 meq/100 ml was found in bull
    seminal fluid (Larson & Salisbury, 1953).

         Sulfur dioxide is strongly bound by plasma proteins in the form
    of - S - Sulfonates. These are gradually cleared from the blood but by
    what mechanism is at present not clear (Gunnison & Benton, 1971;
    Gunnison & Palmes, 1973).

         Sulfur dioxide can form complex additive compounds with other
    substances present in foods, for example aldehydes, ketones and
    sugars. The reaction is reversible, the equilibrium being influenced
    by temperature and pH. It also reacts reversibly with disulfide groups
    in proteins. In foods SO2 is therefore present in free and bound
    forms, the bound form predominating (Allen & Brook, 1970).

         Following oral administration of 10 or 50 mg SO2/kg (as Na HSO3
    mixed with Na2 35SO3), 70 to 95% of the 35S was absorbed from the
    intestine and voided in the urine of mice, rats and monkeys within 24
    hours. The majority of the remaining 35S was eliminated in the
    faeces, the rate being species-dependent. Only 2% or less of 35S
    remained in the carcass after one week. Free sulfite was not detected
    in rat urine even after a single oral dose of 400 mg SO2/kg. Neither
    could induction of liver sulfite oxidase be demonstrated either after
    single, or 30 daily doses of 200 mg SO2/kg/day (Gibson & Strong,

    Effects on DNA

         The possibility that SO2 might cause point mutations was put
    forward by Shapiro et al. (1970) who showed that sulfite can convert
    the nucleic acid base cytosine (which occurs in DNA and RNA) into
    uracil (which is found in RNA only). Hayatsu et al. (1970) confirmed
    the findings and showed that bisulfite binds to certain nuclectides.
    However, exposure of cells in tissue culture to various concentrations
    of SO2 in the medium showed that strain L cells could tolerate 5 ppm
    (0.0005%) SO2 for periods of eight hours provided a recovery period
    followed each exposure. At higher concentrations (500-2000 ppm
    (0.05%-0.5%)) of SO2 there was inhibition of growth; at the 500 ppm
    (0.05%) level the growth was comparable to control cultures. The
    addition of salts of SO2 caused stimulation of growth at lower levels
    and complete inhibition at 2000 ppm (0.5%) NaHSO3 (Thompson & Pace,

    Effects on thiamine

         Treatment of foods with sulfites reduced their thiamine content
    (Morgan et al., 1935; Williams et al., 1935). It has been suggested
    that the ingestion of SO2 in a beverage may effectively reduce the
    level of thiamine in the rest of the diet (Hötzel, 1962).

         Six rats were given a diet providing 40 mg thiamine daily. At
    weekly intervals an additional 160 mg thiamine was given and the
    urinary excretion of thiamine measured on the following two days. When
    the response, in terms of urinary output of thiamine, appeared to be
    constant, 160 mg thiamine was given together with 120 mg potassium
    metabisulfite. It was found that the addition of SO2 greatly reduced
    the urinary output of thiamine, especially on the day when both were
    given together (Causeret et al., 1965).

         In wine containing 400 ppm (0.04%) SO2, 50% of the thiamine was
    destroyed in one week. However, no loss of thiamine was observed in
    48 hours. The small amounts of SO2 resulting from the recommended
    levels of usage in wine are therefore not likely to inactivate the
    thiamine in the diet during the relatively short period of digestion
    (Jaulmes, 1965).

         In a series of studies Hötzel and co-workers (1969) gave
    400 mg/sulfite/person/day to a group of subjects who were fed on a
    thiamine deficient diet. The diet produced signs of vitamin deficiency
    in 50 days and the sulfite, dissolved in wine or grape juice was given
    between days 15-40. No effect on thiamine status was detected by
    measurement of blood thiamine levels, urinary thiamine excretion and
    by determination of thiamine-dependent enzyme activity. Clinical,
    neurophysiological and biochemical investigations produced no
    indication of adverse effects from sulfite. The work of Sharratt
    (1970) also supports the view that SO2 in beverages does not reduce
    the level of thiamine in the rest of the diet.

    Effects on calcium balance

         Interest in this aspect arises from the possibility that sulfate
    formed metabolically from sulfite may serve to increase loss of
    calcium in urine and faeces of man.

         Levels of 0.5 to 0.7% calcium carbonate in the diet caused
    increased faecal excretion and diminished urinary levels of Ca. Levels
    up to 0.2% had no effect on the excretion of Ca (Causeret & Hugot,
    1960). In a further experiment, diets containing 0.5 and 1% calcium
    carbonate and 0.5 and 1% potassium metabisulfite (2885 and 5770 ppm
    (0.2885 and 0.5770%) SO2) were administered to young rats and the
    faecal and urinary excretion of Ca measured for 10 days. At the lower
    level of dietary Ca (0.5%) both levels of the metabisulfite caused a
    significant increase in the urinary excretion of Ca but had no effect
    on the faecal excretion. At the higher dietary Ca level (1%) the
    reverse was found. There was no difference between the effects of the
    two levels of metabisulfite. This was interpreted as being due to
    saturation of the body's capacity to convert sulfite to sulfate (Hugot
    et al., 1965).

         The levels of hepatic vitamin A were determined on both control
    and test rats receiving 1.2 g/l potassium metabisulfite in the
    drinking-water (700 mg/l as SO2). There was an insignificant decrease
    in the vitamin A level in the liver of test animals after 10 days. In
    another experiment, two groups of 40 rats each were kept for four
    months on a diet containing only traces of vitamin A. The drinking-
    water of one group contained 1.2 g/l potassium metabisulfite. Hepatic
    vitamin A levels were determined at the end of each month. A gradual
    reduction in the liver vitamin A levels was observed in both groups.
    The addition of SO2 to the drinking-water did not accentuate this
    reduction (Causeret et al., 1965).


    Special studies on reproduction


         Six groups of 20 male and 20 female rats were mated (group
    matings) after 21 weeks on diets containing 0, 0.125, 0.25, 0.5, 1.0
    or 2.0% Na2S2O5, 10 males and 10 females being remated at 34 weeks.

         Ten male and 10 female F1a rats were mated at 12 and 30 weeks
    old to give F2a and F2b offspring. Ten males and 15 females of the
    F2a generation were mated at 14 and 22 weeks to give F3a and F3b
    offspring. F1a parents and F2a parents were kept on diet for 104 and
    30 weeks respectively. Incidence of pregnancy, birthweight, and
    postnatal survival were all normal. In the Fo first mating, body
    weight gain of offspring was decreased at 2%, and in F1 matings at 1
    and 2%. The F2 first mating showed decreased weight gain of offspring
    in all test groups at weaning but little effect was seen in offspring
    of the second F2 mating. Litter size was significantly decreased at
    0.5% and above in the first F2 mating only. Body weight of Fo adults
    was unaffected, whilst F1 females at 2% and F2 males and females at
    2% both showed slight decreased body weight gain (Til et al., 1972b).

    Special studies on mutagenicity

         Using E. coli as an indicator, the frequency of mutation of the
    C gene of phage lambda was shown to be increased by a factor of 10
    when compared with controls, by treatment with 3M NaHSO3 at pH 5.6 at
    37°C for 1-1/2 hours (Hayatsu & Miura, 1970). Further studies
    indicated sodium bisulfite specifically induces mutations in only
    those mutants which have cytosine-guanine at the mutant site (Mukai et
    al., 1970).

    Acute toxicity
                           Solution    LD50 sodium
    Species      Route       conc.      bisulfite    Reference
    Rat          i.p.         25%         498

    Rabbit       i.p.         25%         300

    Dog          i.p.         25%         244        Wilkins et al., 1968

    Mouse        i.p.       1.25%         675

    Rat          i.p.       5.00%         650

    Rat          i.p.       1.25%         740

         In rabbits, the oral LD50 of sulfite, measured as SO2, was
    found to be between 600 and 700 mg/kg bw (Rost & Franz, 1913).


                                LD50 (mg/kg bw)
    Animal    Route                                     Reference
                      Sodium bisulfite  Sodium sulfite

    Mouse     i.v.         130               175        )
    Rat       i.v.         115                -         )
                                                        ) Hoppe & Goble,
                                                        ) 1951
    Hamster   i.v.          95                -         )
                                              -         )

    Rabbit    i.v.          65                -

    Short-term studies


         In thiamine-deficient rats, daily oral administration of fruit 
    syrup containing 350 ppm (0.035%) of sulfur dioxide in a dose of
    0.5 ml/150 g rat for eight weeks failed to influence growth (Locket, 

         Groups of weanling raze numbering five per group were fed 0.6% 
    sodium metabisulfite (not less than 3400 ppm (0.0340%) as SO2) for 
    six weeks. The diets were either freshly sulfited or stored at room 
    temperature before use. A reduction in growth occurred in rats 
    receiving the fresh diet which was attributed to lack of thiamine. 
    Rats fed the diet which had been stored for 75 days developed signs 
    of thiamine deficiency and additional toxic effects including
    diarrhoea and stunting of growth which could not be reversed by the
    administration of thiamine (Bhagat & Locket, 1964).

         Three groups of 20 to 30 rats containing equal numbers of males 
    and females received daily doses of sulfite dissolved in water or 
    added to wine, and a control group received the same volume of water. 
    The levels of sulfite in the two groups receiving wine were equivalent 
    to 105 mg and 450 mg SO2 per litre respectively and the aqueous 
    solution contained potassium metabisulfite equivalent to 450 mg SO2
    per litre. The effect of this treatment was studied in four successive
    generations, the duration being four months in females and six months

    in males. Groups of animals from the second generation were treated
    for one year. No effect was observed on weight gain, efficiency of
    utilization of protein, biological value of the same protein or
    reproduction. There was also no effect on the macroscopic or
    microscopic appearance of organs or organ weights. The only effect
    observed was a slight diminution in the rate of tissue respiration by
    liver slices in vitro (Jaulmes, 1964).

         Rats were fed sulfite, as Na2S2O5 in stock or purified diet at
    levels from 0.125 to 6% for up to eight weeks. In the preliminary
    study increasing levels of sulfite (0.125 to 2.0% in diet) resulted in
    decreased urinary thiamine excretion. Supplementation of diet with
    50 mg thiamine/kg diet prevented the thiamine deficiency as evidenced
    by reduction of offspring mortality, and weight loss to weaning at the
    2% level of sulfite feeding. Toxic manifestations were noted at 1% and
    above (but not at 0.5%) comprising occult blood in the faeces (1% and
    over), reduced growth rate (2% purified diet, and 6% purified and
    stock diet), blood in the stomach and anaemia (2% and above), spleen
    enlargement, increased haematopoiesis and diarrhoea (4% and above),
    and increased white blood cells (6%). Histopathological changes in the
    stomach occurred at 1% and over (Til, 1970).

         Groups of 10 male and 10 female rats were fed on diets containing
    0 to 8% sodium metabisulfite for 10-56 days. Vitamin deficiency was
    prevented by adding thiamine to the diet. Diets containing 6% and
    above depressed food intake and growth and glandular hyperplasia,
    haemorrhage, ulceration, necrosis and inflammation of the stomach
    occurred. Anaemia occurred in all animals receiving 2% and above and a
    leucocytosis in those receiving 6%. At 4% and above splenic
    haematopoiesis was found. The effects were reversible when sulfite was
    removed from the diet (Til et al., 1970).

         About 120 rats containing equal numbers of each sex were divided
    into two groups, one receiving potassium metabisulfite equivalent to
    0.6% SO2 in the drinking-water, the other group serving as control.
    No effect was observed after treatment for three months on
    reproduction, mortality or blood count. The second and third
    generations were treated in the same way for three months, the only
    effect observed being a significant reduction in the size of the
    litters of treated mothers. No effect of sulfite on digestive enzymes
    in vitro was observed at a level equivalent to 360 mg SO2 per gram
    of protein. No effect on the incidence of dental caries in the rat was
    produced by 0.5% potassium metabisulfite in the dietary regime. Work
    is in progress on the effects of sulfite on the metabolism of
    thiamine, vitamin A and calcium (Causeret, 1964).

         Groups of 20 Wistar rats (10 of each sex) were fed diets
    containing 0.125, 0.25, 0.5, 1.0 and 2.0% of sodium hydrogen sulfite
    (770-12 300 ppm (0.077-0.43%) as SO2) for 17 weeks. A group of 20
    rats on untreated diet served as controls. Immediately after

    preparation, all diets were stored at -18°C in closed glazed
    earthenware containers, for not longer than two weeks. Measurements of
    loss of SO2 on keeping each diet in air for 24 hours at room
    temperature revealed losses amounting to 12.5. 10.0, 14.3, 8.2 and
    2.5% of the sulfite present in the diets as listed above, i.e. with
    increasing SO2 content a decreasing proportion was lost.

         After 124 days there was no effect on the growth of male rats. In
    females, the 2.0% group grew as well as the controls; both these
    female groups were used for fertility studies, had given birth to
    litters during the course of the test, and had raised their young. The
    other female groups on lower levels of dietary sulfite were not mated
    and showed significant depression of growth (as compared with controls
    that had been mated). Haematological measurements at 7-8 weeks (all
    groups) and at 13 weeks (2% and controls) revealed no effect of

         In the diet containing 2% sulfite, thiamine could not be measured
    after 14 days at -18°C; at 1.0% and 0.25% sulfite there was some loss
    of thiamine but this cannot be assessed precisely since the initial
    values are not quoted. Measurements of urinary thiamine excretion
    revealed substantial reduction at one week and particularly at 13
    weeks in all groups receiving more than 0.125% sulfite in the diet.
    Urine concentration tests were not carried out on a sufficient number
    of animals to permit any firm conclusion to be drawn.

         Males and females of the control and 2% groups were mated with
    rats drawn from the main colony. The only untoward findings, with
    females of the 2% group, were lower weight of the offspring at seven
    and 21 days of life and 44.3% mortality as compared with mortalities
    of 0, 2.8 and 3.8% in the other groups of young rats. It is claimed
    that no changes were found in relative organ weight (liver, heart,
    spleen, kidneys, adrenalin, testes) nor in microscopical appearance
    (above organs, stomach, intestine, uterus, teeth and eyes). Since no
    measure of dispersion is quoted, it is impossible to say whether the
    apparent severe reduction in relative liver weight at the 0.125, 0.25,
    0.5 and 1.0% levels is significant (Centraal Instituut voor
    Voedingsonderzoek (T.N.O., 1965)).


         One rabbit given 3 g of sodium sulfite by stomach tube each day
    for 185 days lost weight, but all organs were normal post mortem. Two
    rabbits given 1.08 g daily for 127 days gained weight. Autopsy showed
    haemorrhages in the stomach. Three rabbits given 1.8 g daily for
    between 46 and 171 days lost weight and autopsy showed stomach
    haemorrhages (Rost & Franz, 1913).


         A dose of 3 g of sodium sulfite daily was given by stomach tube
    to a dog weighing 17 kg for 23 days. Another weighing 34 kg was given
    6-16 g of sodium sulfite daily for 20 days (total dose 235 g). No
    abnormalities were observed on autopsy in the first dog, but the
    second dog had haemorrhages in several organs.

         Sodium sulfite was given by stomach tube to 16 growing dogs in
    daily doses of 0.2-4.8 g for 43-419 days; no damage was observed in
    any of the dogs. Sodium bisulfite was given to two dogs by the same
    method and for the same length of time as in the preceding experiment
    in daily doses of 1.08-2.51 g. Examination of heart, lungs, liver,
    kidney and intestine showed no damage. A total of 91-265 g of sodium
    sulfite fed to five pregnant dogs over a period of 60 days had no
    effect on the weight of the mothers or on the weight gain of the
    litters (Rost & Franz, 1913).


         Groups of 20 castrated male, and 20 female weanling Dutch
    Landrace pigs were placed on diets supplemented with 50 mg/kg
    thiamine, and containing 0, 0.06, 0.16, 0.35, 0.83 or 1.72%
    Na2S2O5. Fourteen males and 14 females/group were sacrificed
    at 15-19 weeks and the remainder at 48-51 weeks. In addition a paired
    feeding study on 15 male and 15 female weanling pigs/group was
    performed for 18 weeks at 0 and 1.72% Na2S2O5. Food intake and
    weight gain was reduced at the 1.72% level, but the pair feeding study
    indicated growth and food conversion were not affected when intake was
    controlled. Mortality was not related to sulfite ingestion. Urinary
    and liver thiamine levels decreased with increasing dose, but only at
    1.72% were they reduced below the levels found in pigs on basal diet
    alone. Haematology and faecal occult blood determinations were
    comparable in all groups. Organ/body weight ratios were elevated at
    0.83 and 1.72% for heart, kidney and spleen, and at 1.72% for liver.
    The pair feeding study showed liver and kidney weight ratios to be
    increased at 1.72%. Gross pathology comprised mucosal folds in the
    stomach and black colouration of the caecal mucosa in the top two dose
    levels. At 0.83 and 1.72%, histopathological examination showed
    hyperplasia of mucosal glands and surface epithelium in the pyloric
    and cardiac regions. In the pars oesophagea, intra-epithelial
    microabscesses, epithelial hyperplasia and accumulations of
    neutrophilic leucocytes in papillae tips were observed. In the caecal
    mucosa, macrophages laden with pigment granules (PAS positive
    containing Ci and Fe) were observed at all dose levels, including
    controls. Incidence was markedly increased at 0.83% and above. At
    1.72%, fat-containing Kupffer cells were present in usually high
    numbers in the liver (Til et al., 1972a).

    Long-term studies


         Groups of rats numbering from 18 to 24 per group were fed sodium
    bisulfite in dosages of 0.0125, 0.025, 0.05, 0.1, 0.25, 0.5, 1 or 2%
    of the diet for periods ranging from one to two years. The rats fed
    0.05% sodium bisulfite (307 ppm (0.0307%) as SO2) for two years
    showed no toxic symptoms. Sulfite in concentrations of 0.1% (615 ppm
    (0.0615%) as SO2), or more, in the diet inhibited the growth of the
    rats, probably through destruction of thiamine in the diet (Fitzhugh
    et al., 1946).

         Three groups of weanling rats containing 18, 13 and 19 animals
    received drinking-water containing sodium metabisulfite at levels of
    0 ppm (0%) SO2, 350 ppm (0.035%) SO2 and 750 ppm (0.075%) SO2.
    Prior interaction of the sulfite with dietary constituents was thus
    prevented. The experiment lasted 2-1/2 years and extended over three
    generations of rats. No effects were observed on food consumption,
    fluid intake, faecal output, reproduction, lactation or the incidence
    of tumours (Locket & Natoff, 1960).

         A solution containing 1.2 g of potassium metabisulfite per litre
    of water (700 ppm (0.07%) SO2) was administered to 80 weanling rats
    (40 of each sex) over a period of 20 months. A group of 80 rats given
    distilled water served as controls. It was shown that the intake of
    fluid by the test group was the same as that of the controls (but no
    study appears to have been made of SO2 loss from the metabisulfite
    solution). The intake of SO2 calculated from the consumption of water
    was 30-60 mg/kg bw per day for males and 40-80 mg/kg bw per day for
    females. The following criteria provided no evidence of toxic effect:
    growth rate, food intake, clinical condition, haematological indices
    of blood and bone marrow (except peripheral leucocyte count, which was
    increased in males), organ weights (except spleen weight, which was
    heavier in females), micropathological examination of a large number
    of tissues and mortality rate. Fatty change in the liver was mostly
    slight or absent, with a similar incidence and severity in test and
    control groups. Reproduction studies over two generations revealed no
    effect except for a slightly smaller number of young in each litter
    from test animals and smaller proportion of males in each of these
    litters. Growth of the offspring up to three months was almost
    identical in test and control groups (Cluzan et al., 1965).

         Four groups of 20 rats (10 of each sex on standard diet) were
    given daily doses (30 ml/kg bw) of red wine containing 100 and
    450 ppm (0.01% and 0.045%) SO2, an aqueous solution of potassium
    metabisulfite (450 ppm (0.045%) SO2) and pure water by oral
    intubation on six days each week for four successive generations. The
    females were treated for four and the males for six months; the second
    generation was treated for one year. The only effect seen was a slight

    reduction in hepatic cellular respiration. All other parameters
    examined: weight gain, weight and macroscopic or histological
    appearance of various organs, appearance and behaviour, proportion of
    parturient females, litter size and weight, biological value of a
    protein sample, showed no changes attributable to SO2 (Lanteaume et
    al., 1965).

         Groups of 20 male and 20 female rats were fed 0, 0.125, 0.25,
    0.5, 1.0 or 2.0% Na2S2O5 in a diet enriched with 50 ppm (0.005%)
    thiamine for two years. Animals were stressed by breeding at 21 weeks,
    and again for half of each group at 34 weeks. Percentage loss of
    sulfite from the diet decreased with increasing dietary concentration,
    but increased with increasing time. Thiamine loss increased with
    increasing sulfite concentration. Body weight, food consumption,
    kidney function, and organ weights were all unaffected. Thiamine
    content of urine and liver showed a dose-related decrease commencing
    at 0.125 and 0.25% respectively. However, thiamine levels at 2% were
    comparable to levels in control rats. Marginally reduced haemoglobin
    levels were noted on three occasions in females at 2%, and occult
    blood was noted in faeces at 1% and above. In 10% of the females at
    0.25%, and in 10% of the males at 0.5% sulfite slight indications of
    intestinal blood loss were noted at week 32 only. Pathological changes
    were limited to the stomach (either hyperplasia or inflammation) and
    occurred at 1% and above. Incidence of neoplasms was not increased
    above normal levels at any site at any dose (Til et al., 1972b).


         In man, a single oral dose of 4 g of sodium sulfite caused toxic
    symptoms in six of seven persons. In another subject, 5.8 g caused
    severe irritation of the stomach and intestine (Rost & Franz, 1913).

         The vomiting reflex in man appeared regularly with doses of
    sulfite equivalent to less than 250 mg SO2, i.e. 3.5 mg SO2 per kg
    bw (Lafontaine & Goblet, 1955). (See also under: effects on thiamine).


         Long-term and 3-generation studies on rats using metabisulfite
    in a diet with added thiamine showed a no-effect level of 0.215%
    metabisulfite (equivalent to 72 mg/kg bw per day SO2). This level
    is higher than that indicated by the earlier studies involving
    metabisulfite administration to rats in drinking-water (equivalent to
    35 mg/kg bw per day SO2).

         The effect of sulfite on food components needs further study
    since the earlier observations of toxicity from the feeding of stored
    sulfited foods point to the formation of some toxic addition compound.
    Human studies over short periods showed that 400 mg/day produced no
    effect on thiamine excretion.

         While it has been shown that sodium bisulfite reacts with DNA and
    produces mutation in bacteria, the, relevance of these observations to
    man is highly questionable. The mutagenicity of bisulfite in bacteria
    is manifest only at low pH. It has been shown that maximal mutagenic
    activity of bisulfite occurs at pH 5.0 while at pH. 7 and 8 no
    induction of mutants was observed. Further, studies in Drosophila
    reveal no elevation of mutation frequency at two levels of exposure
    including one which killed a sizeable proportion of flies. Based on
    these observations, it can be assumed that bisulfite poses no threat
    to genetic material at physiological pH. However, confirmation of this
    claim utilizing mammalian cell in culture is recommended. Any one of
    several mammalian cell mutational assay systems might be applied for
    this purpose.


    Level causing no toxicological effect

         Rat: 0.215% metabisulfite in the diet equivalent to 70 mg/kg bw
    per day calculated as SO2.

    Estimate of acceptable daily intake for man

         0-0.7* mg/kg bw


         Desirable: Additional mutagenic studies in a mammalian system.
    Studies over longer periods in man.


    Allen, R. J. L. & Brook, M. (1970) Third International Congress of
         Food Science & Technology, Washington

    Bhagat, B. & Locket, M. F. (1960) J. Pharm. Pharmacol., 12, 690

    Bhagat, B. & Locket, M. F. (1964) Food Cosmet. Toxicol., 2, 1

    Causeret, J. (1964) Unpublished report of work in progress submitted
         to WHO

    Causeret, J. et al. (1965) Fruits, 20, 109

    Causeret, J. & Hugot, D. (1960) C.R. hebd. Séanc. Acad. Sci., Paris,
         250, 401


    *    As SO2.

    Centraal Instituut voor Voedingsonderzoek T.N.O. (1964) Unpublished

    Cluzan, R., Causeret, J. & Hugot, D. (1965) Annls. Biol. anim.
         Biochim. Biophys., 5(2), 267

    Fitzhugh, O. G., Knudsen, L. F. & Nelson, A. A. (1946) J. Pharmacol.
         exp. Ther., 86, 37

    Gibson, W. B. & Strong, F. M. (1973) Metabolism and elimination of
         sulfite by rats, mice and monkeys, Food Cosmet. Toxicol., 11,

    Gunnison, A. F. & Benton, A. W. (1971) Arch. Environ. Health, 22,

    Gunnison, A. F. & Palmes, E. D. (1973) Tox. & Appl. Pharm., 24,

    Hayatsu, H. & Miura, A. (1970) The mutagenic action of sodium
         bisulfite, Biochem. Biophys. Res. Comm., 39, 156

    Hoppe, J. O. & Goble, F. C. (1951) J. Pharmacol. exp. Ther., 101, 101

    Hötzel, D. (1962) Verh. dt. Ges. inn. Med., 67, 868

    Hötzel, D. et al. (1969) Int. Z. Vitamin Forsch., 39, 372

    Hugot, D., Causeret, J. & Leclerc, J. (1965) Annls. Biol. anim.
         Biochim. Biophys., 5, 53

    Jaulmes, P. (1964) Unpublished report of work in progress submitted to

    Jaulmes, P. (1965) Eœtrait"Sommaire de l'Activité des Services
         Centraux de l'Intendance No. 163, 1e Tri."

    Lafontaine, A. & Goblet, J. (1955) Arch. belges Méd. soc., 13, 281

    Lanteaume, M. T. et al. (1965) Annls. Falsif. Expert. chim., 58, 16

    Larson, B. L. & Salisbury, G. W. (1953) J. biol. Chem., 201, 601

    Locket, M. F. (1957) J. Pharm. (Lond.), 9, 605

    Locket, M. F. & Natoff, I. L. (1960) J. Pharm. Pharmacol., 12, 488

    Morgan, A. F. et al. (1935) J. Nutr., 9, 383

    Mukai, F., Hawryluk, I. & Shapiro, R. (1970) The mutagenic specificity
         of sodium bisulfite, Biochem. Biophys. Res. Comm., 39, 983

    Pfleiderer, G., Wieland, T. & Jeckel, D. (1956) Biochem. Z., 328, 187

    Rost, E. (1933) Handbuch der Lebensmittel-Chemie, Band I, p. 993,
         Springer Verlag

    Rost, E. & Franz, F. (1913) Arb. Gesundh.-Amte (Berl.), 43, 187

    Shapiro, R. et al. (1970) J. Amer. Chem. Soc., 92, 422-424

    Sharratt, M. (1970) In: Allen, R. J. L. & Brook, M. (1970) Third
         International Congress of Food Science & Technology, Washington

    Swan, J. M. (1957) Nature (Lond.), 180, 643

    Thompson, J. R. & Pace, D. M. (1962) Canad. J. Biochem. Physiol., 40,

    Til, H. P. (1970) Toxicologisch Onderzoek Naar de Werking van Sulfiet
         bij Ratten, Varkens en Kwartels. Thesis - Rijksuniversiteit te
         Utrecht, March

    Til, H. P., Feron, V. J. & de Groot, A. P. (1972a) The toxicity of
         sulfite. II. Short and long-term feeding studies in pigs. Fd.
         Cosmet. Toxicol., 10, 463

    Til, H. P., Feron, V. J. & de Groot, A. P. (1972b) The toxicity of
         sulfite. I. Long-term feeding and multigeneration studies in
         rats. Fd. Cosmet. Toxicol., 10, 291-310

    Wilkins, J. W. jr, Greene, J. A. jr & Weller, J. M. (1968) Toxicity of
         intraperitoneal bisulfite, Clin. Pharmac. Ther., 9, 328

    Williams, R. R. et al. (1935) J. Amer. chem. Soc., 57, 536

    See Also:
       Toxicological Abbreviations
       Sulfur dioxide and sulfites (WHO Food Additives Series 18)
       Sulfur dioxide and sulfites (WHO Food Additives Series 21)