Document jw05ZXx1K4RbOm5rBVO4oQE9

Exposure of tetrathal employees DRAFT a. Mean total chlorodibenzodioxin content of product (Samples //1-11) is 68 ppb (68 pg mg"1 of tetrathal). b. Mean content of tetra- through heptachlorodibenzodioxin in product is 47 ppb (47 pg/mg tetrathal). c. Because tetrathal is irritating, assume that dermal exposure can be neglected; thus inhalation affords the only significant route of' exposure. Respiratory protection is worn; assume 90% protection and an inhalation volume of 10 m3/shift, a mean dust level of <2.9 mg tetrathal/m3 air (see J. Wolfsburger memo attached) and complete absorption of all inhaled dust. Thus tetrathal intake is 0.1 x<2.9 x 10 = <2.9 mg/d. d. Intake of all chlorodibenzodioxins is: <2.9 mg tetrathal/d x 68 pg CDD/mg tetrathal = <197 pg/d. e. Intake of tetra- through heptachlorodibenzodioxins is: <2.9 mg/d x 47 pg/mg = <136 pg/d. f. Assuming 70 kg body mass, intake becomes: 1. For all chlorodibenzodioxins, <197/70 = <2.8 pg/kg/d. 2. For CI4-CI7 dibenzodioxins, <136/70 = <1.9 pg/kg/d. 1/23/85 2