Toxicity Profile for Hydrogen cyanamide (1993)

Abstract

Hydrogen cyanamide was irritant to human skin and its vapour caused respiratory tract irritation. In rabbits, local application of calcium cyanamide or sodium hydrogen cyanamide caused severe skin effects, and the latter also caused severe eye irritation. Hydrogen cyanamide induced skin sensitization in some individuals and general intolerance reactions (including skin rashes) have developed following exposure to cyanamide and alcohol. In man, absorption of the cyanamide ion has been associated in particular with effects on the nervous system, cardiovascular system, eyes and liver. High acute oral and dermal toxicity has been demonstrated in laboratory animals for hydrogen and calcium cyanamide, whilst sodium hydrogen cyanamide has shown moderate acute oral toxicity. The target sites for cyanamide's action in acute oral studies included the eyes, liver and nervous system.

In studies involving repeated oral administration of hydrogen cyanamide to rodents, cellular degeneration in the testes and tissue changes in the ovaries, urinary bladder, kidneys and liver were reported, whereas calcium cyanamide formulations produced tissue abnormalities in the liver, bile duct, thyroid, pituitary, adrenals, spleen and male reproductive system (resulting in decreased sperm production). Fertility was reduced and embryo survival decreased in rats given repeated oral doses of hydrogen cyanamide. Oral carcinogenicity studies with hydrogen cyanamide or a calcium cyanamide formulation in rats or mice gave equivocal findings. Calcium cyanamide was weakly mutagenic in an Ames bacterial assay and was genotoxic to yeast. Hydrogen cyanamide gave no evidence of activity in a range of genotoxicity screening assays.