Inhalation toxicity studies of aqueous dispersion resin

Area of Science:

• Toxicology
• Environmental Health
• Polymer Science

Background:

• Aqueous dispersion resin (ADR) is a key component in hair-spray formulations, requiring safety assessments.
• Understanding the toxicological profile of ADR is crucial for consumer product safety.

Purpose of the Study:

• To evaluate the toxicological effects of Aqueous Dispersion Resin (ADR) through a series of inhalation studies.
• To determine the acute, sub-chronic (9-day), and chronic (90-day) toxicity of ADR aerosol exposure in animal models.

Main Methods:

• Conducted whole-body aerosol inhalation studies with varying durations (acute, 9-day, 90-day) and exposure concentrations.
• Utilized male and female rats, assessing clinical signs, body weight, lung weights, and histopathological changes.
• Determined LC50 for acute exposure and NOEL for the 90-day study.

Main Results:

• Acute exposure showed no mortality or lesions, with LC50 > 1.07 mg/L.
• 9-day exposure revealed alopecia and increased lung weights at higher concentrations (500-1000 mg/m³), with histopathological findings.
• 90-day exposure demonstrated increased lung weights and histopathological effects (alveolar histiocytosis, pneumonitis) at 100 and 300 mg/m³, but not at 30 mg/m³.

Conclusions:

• ADR is not acutely toxic via inhalation at tested concentrations.
• Repeated inhalation exposure to ADR can cause lung-related toxicity.
• A no-observable-effect level (NOEL) for 90-day inhalation exposure was established at 30 mg/m³.