Health-based recommended occupational exposure limits for hexachlorobenzene.

Recommendation: In the evaluation an acceptable daily intake of 0.3 mg/day was calculated for humans. To come to a MAC value for inhalation in the working environment the following asumptions are made: 1) Absorption of HCB by oral administration or inhalation is the same. 2). The qualitative and quantitative effects of HCB intoxication do not differ whether HCB is inhaled or by oral intake. The amount of air inhaled in a 8 hours working day during heavy labor is 10 m3. On the basis of the assumptions made a MAC-value of 0.3/10 mg/m3 = 30 µg/m3 TWA 8 hr is recommended.From a total diet study in the Netherlands (Greve, 1986) the average daily intake was estimated to be 1 µg/person, which does not contribute considerably to the acceptable inhalatory occupational exposition.