• Acute reactions: direct cytotoxic damage to keratinocytes through oxidation, reduction, desiccant, vesicant, or ion disruption; decrescendo phenomenon
• Repeated exposures: damage to cell membrane

Irritants and mechanisms of toxicity

• Detergents: Barrier disruption, protein denaturation, membrane toxicity
• Acids: Protein denaturation, cytotoxicity
• Alcohols: Protein denaturation
• Alkalis: Barrier lipid denaturation, cytotoxicity through cellular swelling
• Oils: Disorganization of barrier lipids
• Organic solvents: Solubilization of membrane lipids, membrane toxicity
• Oxidants: Cytotoxicity
• Reducing agents: Keratolysis
• Water: If barrier is disrupted, cytotoxicity through swelling of viable epidermal cells