FAO Nutrition Meetings
Report Series No. 40A,B,C
TOXICOLOGICAL EVALUATION OF SOME
ANTIMICROBIALS, ANTIOXIDANTS, EMULSIFIERS,
STABILIZERS, FLOUR-TREATMENT AGENTS, ACIDS AND BASES
The content of this document is the result of the deliberations of the
Joint FAO/WHO Expert Committee on Food Additives which met at Rome,
13-20 December, 19651 Geneva, 11-18 October, 19662
1 Ninth Report of the Joint FAO/WHO Expert Committee on Food
Additives, FAO Nutrition Meetings Report Series, 1966 No. 40;
Wld Hlth Org. techn. Rep. Ser., 1966, 339
2 Tenth Report of the Joint FAO/WHO Expert Committee on Food
Additives, FAO Nutrition Meetings Report Series, 1967, in press;
Food and Agriculture Organization of the United Nations
World Health Organization
ACETIC ACID, GLACIAL
Chemical name Acetic acid
Empirical formula C2H4O2
Structural formula CH3COOH
Molecular weight 60.05
Definition Glacial acetic acid contains not less
than 99.0 per cent. C2H4O2.
Description A colourless liquid or crystalline
solid, having a pungent characteristic
odour and, when well diluted with water,
an acid taste.
Uses As acidifier, flavouring agent, for the
prevention of rope in baking and as a
Acetate enters naturally into the metabolism of the body. It is
absorbed from the gastrointestinal tract and through the lungs and
almost completely oxidized by tissues. The metabolic pathways are
reasonably well-known and involve the formation of ketone bodies.
Isotope experiments have shown the various C atoms to be utilized in
the formation of glycogen, intermediates of carbohydrates and fatty
acid synthesis as well as cholesterol synthesis. In addition it
participates in the acetylation of amines and formation of proteins of
plasma, liver, kidney, gut mucosa, muscle and brain (von Oettingen,
Animal Route LD50) References
Mouse oral 4 960 Woodard et al.,
(free acid) 1941
Rat oral 3 310 Woodard et al.,
(free acid) 1941
oral 3 530 Smyth, 1951
Rabbit rectal 1 200 Dreyfus, 1920
(free acid) (LD, 1 hour)
s.c. 1 200 Dreyfus, 1920
(free acid) (LD, 48 hours)
oral 1 200 Dreyfus, 1920
(free acid) (LD, 6 days)
Toxic effects of acetic acid are due to its irritant properties
as well as its effect on the central nervous system and kidneys. Large
oral doses causes narcotic C.N.S. depression and death in rats and
mice (Woodard et al., 1941).
Rat. Groups of 3-6 rats were given 0.01, 0.1, 0.25 and 0.5 per
cent. acetic acid in drinking water for periods of from 9-15 weeks.
fluid intake was the same in all groups; at the 0.5 per cent. level
there was immediate progressive reduction in body-weight gain, loss of
appetite and fall in food consumption to 27 per cent. Mortality rate
was unaffected (Sollmann, 1921). In another experiment groups of 3-4
rats survived 14 days when given 1800 mg/kg body-weight/day free acid
intragastrically or 4200-4800 mg/kg body-weight sodium acetate, but
only 3-5 days on daily intragastric 2400. mg/kg body-weight free acid.
Animals lost weight before death and showed blistered paws and
reddened noses. No autopsies were done (Hemmingway & Sparrow, 1942).
Intragastric intubation of 3 ml of 10 per cent. solution acetic acid
to rats for 90 days produced a drop in haemoglobin concentration and
erythrocyte count (Wysokinska, 1952).
Swine. Four groups of 2 young pigs were fed daily diets
containing 0, 240, 720, 960 and 1200 mg/kg body-weight/day for
successive 30-day periods to a total of 150 days. There were no
significant differences in growth rate, weight gain, early morning
urinary ammonia and terminal blood pH between controls and test
groups. No autopsies were done (Lamb & Evvard, 1919).
No animal studies are available.
About 1 g/day of acetic acid present in vinegar and other items
of food and drink has been consumed by man for centuries apparently
without causing any adverse effects. However, continued ingestion of
large doses has been regarded as a contributory factor in the
development of Laennec type of liver cirrhosis (Singer, 1936).
Acetic acid has a sufficiently acid taste to limit the amount
used in foods. Human studies determining the maximum metabolic load of
acetate are not available. In evaluating the acceptance of acetic
acid, emphasis is placed on its established metabolic pathways and its
normal consumption by man.
For purposes of evaluation all sources of acetate used as food
additives should be considered together. Since acetic acid has a
sufficiently acid taste to limit the amount used in foods, it is not
necessary to indicate acceptable daily intakes for man.
Dreyfus, L. (1920) Compt. rend. soc. biol., 83, 136
Hemmingway, A. & Sparrow, A. (1942) Proc. Soc. exper. Biol. Med.,
Lamb, A. R. & Evvard, M. J. (1919) J. Biol. Chem., 37, 317
von Oettingen, W. F. (1960) Arch. Ind. Health, 21, 28
Singer, L. (1936) Munch. med. Wschr., 83, 1288
Sollmann, T. (1921) J. Pharm. Exp Therap., 16, 463
Woodard, G., Lange, S. W., Nelson, K. W. & Calvery, H. O. (1941)
J. Ind. Hyg. Toxic., 23, 78
Wysokinska, Z. (1952) Roczniki Panstwowego Zakladu Hig., 3, 273