Toxicological evaluation of some food
additives including anticaking agents,
antimicrobials, antioxidants, emulsifiers
and thickening agents
WHO FOOD ADDITIVES SERIES NO. 5
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.
This substance has been evaluated for acceptable daily intake by
the Joint FAO/WHO Expert Committee on Food Additives (see Annex 1,
Ref. No. 7) in 1963.
The previously published monograph has been revised and is
reproduced in its entirety below.
No information available.
LD50 values have not been found in the literature.
Subcutaneous implantation or injection into rats produced a
foreign-body giant-cell reaction (Tedeschi & Mangiantini, 1956;
Zbinden & Studer, 1957).
Four groups of six rats received diets containing 5%, 10%, 20%
and 30% of agar respectively for 10 weeks. The group receiving the 10%
diet gained weight about 20% faster than the controls; the other
groups gained weight at the same rate as the controls. The rats fed
diets containing 20% and 30% of agar required significantly more feed
and water per gram of weight gain than the control group (Nilson &
Six weanling male rats fed a diet containing 25% of agar for four
weeks showed growth retardation during the third week. The dry weight
of the cleaned stomach and caecum was found moderately increased.
Colon and rectum were more than twice as heavy as in the controls
OBSERVATIONS IN MAN
For the last 50 years agar has been used as a mild laxative for
human subjects in daily doses of 4-15 g (Sollmann, 1957).
Agar is consumed traditionally as food though not as a nutrient.
The effect on weight gain observed in rats was probably due to the
lack of utilization of agar, or to its laxative effects, or both. The
evaluation is based on human data where doses above 5 g only cause a
laxative effect. Further work is desirable to investigate potential
storage of macro molecules in the body.
Estimate of acceptable daily intake for man
Fischer, J. E. (1957) Amer. J. Physiol., 188, 550
Nilson, H. W. & Schaller, J. W. (1941) Food Res., 6, 461
Sollmann, T. (1957) A Manual of Pharmacology, Philadelphia & London,
Saunders, p. 207
Tedeschi, G. G. & Mangiantini, M. T. (1956) Arch. Sci. biol., 40, 504
Zbinden, G. & Studer, A. (1957) Schweiz. Z. allg. Path., 20, 469
* See relevant paragraph in the seventeenth report, pp. 10-11.