Adverse Outcome Pathway for Antimicrobial Quaternary Ammonium Compounds

Area of Science:

• Toxicology
• Environmental Health
• Cell Biology

Background:

• Quaternary ammonium compounds (QACs) are widely used antimicrobials in household and industrial settings.
• Applications include sanitizers, disinfectants, food processing, water treatment, and cosmetics.
• Two common QACs, ADBAC and DDAC, are investigated for potential adverse health effects.

Purpose of the Study:

• To determine the Adverse Outcome Pathway (AOP) for respiratory and gastrointestinal effects of ADBAC and DDAC.
• To elucidate the cellular mechanisms underlying QAC toxicity.
• To inform risk assessment strategies for QACs.

Main Methods:

• The study proposes a mechanism of action for QACs based on existing knowledge.
• It focuses on cellular and tissue-level effects following inhalation or ingestion.
• No new experimental data was generated; it's a pathway elucidation study.

Main Results:

• QACs integrate into epithelial cell membranes, disrupting membrane fluidity and integrity.
• Mitochondrial dysfunction and reduced ATP production are potential effects.
• Cell death (lysis, necrosis, apoptosis), inflammation, edema, and mucus production occur.
• Primary adverse outcome is epithelial degeneration and dysplasia.
• QACs show no significant metabolism or distribution.

Conclusions:

• A clear Adverse Outcome Pathway for QACs leading to tissue damage is proposed.
• The mechanism involves direct cellular toxicity and inflammation.
• The findings support replacing default Uncertainty Factors with Data Derived Extrapolation Factors in risk assessments for QACs.