Review of the toxicology of three alkyl diamines

Three alkyl diamines, which are by-products formed and separated during the production of hexamethylene diamine, have been tested, mostly for their acute toxicity. This paper reviews methodologies used and the results obtained from these three chemicals. All three tested [2-methyl-1,5-pentanediamine (2-MP), 1,3-diaminopentane (DAMP), and 1,2-cyclohexanediamine (DCH)] were 95% pure and were supplied by the DuPont Company. The acute toxicity of all three chemicals is relatively low with acute oral lethal levels in the rat ranging from 1000 to 2300 mg/kg. Single 4-h inhalation exposures show similarly low toxicity with lethality produced in the rat at concentrations ranging from 2.9 to 4.3 mg/L. These diamines are severe skin irritants in both the rabbit and the guinea pig and are also severe eye irritants (studied only in 2-MP). Dermal sensitization was seen in the guinea pig with DAMP and DCH but not with 2-MP. The irritant dose of these materials was shown in repeated exposure inhalation studies when 2-MP and DCH produced irritation in the upper respiratory tract (point of contact) with some lower lung involvement but no significant systemic effects. 2-MP when fed to rats produced a slight body weight effect at dose equivalents of 800 mg/kg with no other parameters affected. All three materials were inactive in Salmonella, and 2-MP did not produce chromosomal aberrations in cultured human lymphocytes. The main effects of this series of diamines appear related to their irritant properties, and attention needs to be paid to their delayed hypersensitivity potential.