Toxicity of Chlorobenzenes and Nitrobenzene

In man, o-dichlorobenzene causes severe poisoning at concentrations of 300 ppm [239]. 25 ppm to 100 ppm have a pungent odour and produce disorders [239]. In the case of p-dichlorobenzene, concentrations of 160 ppm produce disorders, and 50-80 ppm are irritating to the eyes [239]. At concentrations of about 15 ppm, neither compound produces any discomfort [239]. 

Nitrobenzene concentrations of 200 ppm cause severe poisoning while 1-40 ppm produce disorders [239]. 

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