FD & C Red No. 3 (erythrosine), a commonly used food additive, was adm
inistered to pregnant Osborne-Mendel rats to study its teratogenic pot
ential. Dosing solutions of 0.05, 0.1, 0.2 or 0.4% in distilled water
were available at all times and corresponded to daily doses of 64, 121
, 248 and 472 mg FD & C Red No. 3/kg body weight. Distilled water serv
ed as the control. On gestation day 20, the animals were killed and ca
esarean sections were performed. The treated animals consumed less flu
id than did the control animals, but only random decreases were statis
tically significant and no dose relationship was seen. Only the 0.2% g
roup consumed significantly more feed than the controls during gestati
on. Maternal weight gain during days 0-20 was not significantly affect
ed in any group. No dose-related changes were seen in maternal clinica
l findings, implantations, foetal viability, foetal size (weight and l
ength) or visceral development. No dose-related teratogenesis was seen
. Skeletal development was not affected; the few statistically signifi
cant increases in skeletal variations were not dose related and were c
onsidered to be random. FD & C Red No. 3 was neither foetotoxic nor te
ratogenic at the dose levels tested in drinking water.