Inhalation Toxicity Studies of Aqueous Dispersion Resin

The study investigated the inhalation toxicity of aqueous dispersion resin (ADR) used in hair-spray formulations through acute, 9-day, and 90-day exposure tests. In the acute study, no deaths or lesions were observed, indicating an LC50 value greater than 1.07 mg/L. In the 9-day study, exposure to 1000 mg/m3 resulted in unkempt fur and alopecia, with increased lung weights and histopathological effects like alveolar histiocytosis and interstitial pneumonitis in the 500- and 1000-mg/m3 groups. The 90-day study showed increased lung weights and histopathological changes in the 100- and 300-mg/m3 groups, but no effects at 30 mg/m3, establishing a no-observable-effect level (NOEL) at 30 mg/m3.