Methyl methacrylate: inhalation developmental toxicity study in rats

Area of Science:

• Toxicology
• Developmental Biology
• Reproductive Toxicology

Background:

• Methyl methacrylate is a widely used industrial chemical.
• Understanding its potential reproductive and developmental risks is crucial for occupational safety.

Purpose of the Study:

• To evaluate the developmental toxicity of methyl methacrylate following vapor inhalation exposure in pregnant rats.
• To determine if methyl methacrylate causes embryo-fetal toxicity or malformations at exposure levels causing maternal toxicity.

Main Methods:

• Pregnant rats (Crl:CD) were exposed to methyl methacrylate vapor (0, 99, 304, 1,178, 2,028 ppm) for 6 hr/day on gestation days 6-15.
• Maternal parameters (body weight, feed consumption, clinical signs) were monitored. Uterine and fetal parameters (corpora lutea, implantations, resorptions, fetal weight, external, skeletal, and visceral alterations) were assessed on day 20 of gestation.

Main Results:

• Maternal toxicity, including transient body weight and feed consumption decreases, was observed at all exposure levels.
• No treatment-related deaths occurred. No significant changes in reproductive parameters (corpora lutea, implantations, resorptions, litter size, sex ratio) were noted.
• Fetal body weights were similar across groups. No treatment-related increases in external, visceral, or skeletal malformations or developmental variations were observed.

Conclusions:

• Methyl methacrylate vapor inhalation up to 2,028 ppm did not induce embryo-fetal toxicity or malformations in rats.
• Developmental toxicity was not observed even at exposure levels that caused maternal toxicity, suggesting a low risk for developmental effects.