DEVELOPMENTAL TOXICITY EVALUATION OF A SCRUBBING SOLUTION USED IN PETROLEUM REFINERIES

The developmental toxicity potential of a scrubbing solution used exte nsively in petroleum refineries to remove CO2 from hydrogen gas stream s was evaluated via inhalation. Pregnant female CD (Sprague-Dawley) ra ts were exposed to aerosols of a ''used'' scrubbing solution at 0.05, 0.1, 0.2, or 0.3 mg/l for 6 h/d on d 6-19 of pregnancy. Control animal s were exposed to filtered air under the same exposure conditions. Dam s were sacrificed on d 20 of pregnancy and a laparohysterectomy was pe rformed. The mass median aerodynamic diameter of the aerosol revealed that all particles ranged from 1.6 to 2.8 mu m, with geometric standar d deviations between 2.0 and 2.3 mu m. The overall pregnancy rate was high (>95%) and equivalent across all groups. All pregnant dams had li ve litters, and 22-24 litters were examined in each group. Treatment-r elated clinical signs consisted of rales, observed at all exposure lev els, and gasping noted only at the 0.3 mg/l exposure level. The occurr ence of rales was presumably a localized effect on the respiratory tra ct and likely due to the irritating properties of the scrubbing soluti on. Maternal toxicity was exhibited in the 0.3 mg/l group, including r educed body weight, weight gain, and food consumption and one possible treatment-related death on gestation d 17. At scheduled necropsy, the re were no treatment-related gross pathological observations and no st atistically significant reproductive and developmental effects. The in cidences of fetuses with skeletal variations involving the sternum wer e clustered in two litters at the highest exposure level with atypical ly low term fetal body weights. Under the conditions of this investiga tion, potassium carbonate scrubbing solution is not a selective develo pmental toxicant.