We have shown that the germ cell death induced by the glycol ether metabolite methoxyacetic acid can be blocked by calcium channel blockers and that this appears to be due to inter-cellular calcium movement. This happens at similar concentrations in both humans and rats, and can be blocked in both species. While the nature of the cell death in humans appears morphologically to be slightly different from that in rats, biochemically the effects are similar. These data indicate that innate susceptibility of human and rodent testes to this toxicant is the same, which means that the apparent differences in sensitivity found in previous epidemiology studies must be due to other factors.