Toxicities of combinations of pentachloronitrobenzene with mercuric chloride or cadmium chloride,and hexachlorobenzene with mercuric chloride administered to rats

1. Pentachloronitrobenzene (PCNB) and HgCl₂, PCNB and CdC1₂, and hexachlorobenzene (HCB) and HgCl₂ were investigated for their acute oral toxicity in rats, individually and as combinations in various ratios of the organochlorine pesticides to the heavy metal chlorides.

2. The toxicity of mixtures of low dosages of the pairs tested was higher than the sum of the toxicities produced by the individual doses.

3. At increased dosages of the components in the combinations PCNB-HgCl₂ and PCNB-CdCl₂, the combined lethality tended towards the sums of the effects of the individual doses.