Inhalation toxicity of methylglutaronitrile in rats

Area of Science:

• Toxicology
• Industrial Hygiene
• Occupational Health

Background:

• Methylglutaronitrile (MGN) is an industrial solvent and intermediate utilized in the fiber industry.
• Understanding the toxicological profile of MGN is crucial for occupational safety and risk assessment.

Purpose of the Study:

• To evaluate the subchronic toxicity of Methylglutaronitrile (MGN) in male rats following inhalation exposure.
• To determine the no-observed-adverse-effect level (NOAEL) for MGN.

Main Methods:

• Male rats (20/group) were exposed nose-only to MGN aerosol/vapor at concentrations of 5, 25, or 200 mg/m3 for 6 hours/day, 5 days/week over 4 weeks.
• Clinical observations, body weight, hematology, clinical pathology, and neurobehavioral tests were assessed post-exposure and after a 4-week recovery period.

Main Results:

• Body weight depression was observed in the 200 mg/m3 group during exposure.
• Minimal hematologic changes (decreased RBC, hemoglobin, hematocrit; increased reticulocytes) occurred at 200 mg/m3, which normalized during recovery.
• No significant effects were noted in clinical observations, pathology, or neurobehavioral assessments across all groups.

Conclusions:

• The no-observed-adverse-effect level (NOAEL) for Methylglutaronitrile (MGN) in this study was determined to be 25 mg/m3, based on the absence of adverse effects at this concentration.
• MGN exhibits a low order of toxicity with transient effects observed only at the highest exposure concentration.