The decomposition of N-hydroxyacetaminophen (N-acetyl-N-hydroxy-p-aminophenol, 2), a postulated toxic metabolite of acetaminophen (N-acetyl-p-aminophenol, 1) in aqueous solution is quantitatively accounted for by the appearance of equimolar amounts of p- nitrosophenol and acetaminophen. The rate of decomposition depends on initial concentration and varies with pH. Antioxidants decrease the rate of decomposition and ...