Mice had trouble walking and rats developed tremors. High levels of heptachlor in the feed for several weeks damaged the livers of rats and the livers and adrenal glands of mice. We do not know if heptachlor or the epoxide affect the ability of men or women to have children. Some of the offspring had cataracts and some didn't live long after birth. The International Agency for Research on Cancer has determined that heptachlor and heptachlor epoxide are not classifiable as to their carcinogenicity to humans because insufficient data are available to establish a clear assessment.
Laboratory tests can measure heptachlor and heptachlor epoxide following exposure to high levels.
The blood tests for these chemicals must be done within a short period after exposure. Levels in fat can be measured for a much longer period after exposure. If heptachlor or heptachlor epoxide are found in your fat, it isn't possible to tell exactly when you were exposed to these chemicals or if harmful health effects will occur. For up to 10 days, a child should not drink water with greater than 10,000 ppt heptachlor. For longer exposures, a child should not drink water with greater than 5,000 ppt heptachlor or 150 ppt heptachlor epoxide.