Scientific Basis for Swedish Occupational Standards XXII

76) reports inhibited growth, meningoceles/myeloceles and some deaths in embryos of rats given daily intraperitoneal injections of KCN (aqueous solution) during the first 15 days of gestation (3 mg/kg b.w. per injection). In an experiment in which rats were given NaCN by gavage (6 mg/kg b.w. in water) on day 10 of gestation, morphological anomalies were noted in some fetuses 48 hours after the administration. Clinical indications of toxicity (including deaths) were observed in the mothers (71). In studies in which pregnant pigs and rats (80, 81) were fed on cassava containing up to 1250 mg KCN/kg, the only observed toxic effects on reproduction were minor metabolic differences and lower relative organ weights in fetuses at doses affecting the mothers. In an NTP study, mice and rats were given drinking water containing 30, 100 or 300 mg NaCN/liter (rats: about 1.6-13 mg CN/kg b.w./day; mice: about 3-27 mg CN/kg b.w./day) for 13 weeks, and examined for effects on various reproduction parameters (reproductive toxicity at lower doses was not studied). Effects were