A 3-year survey is reported of acute poisoning by Wright's Vaporizing Fluid which covered a change in formulation from 90% cresol to 10% chlorocresol. Of 160 children (average age 2.5 years) and 12 adults, 21.5% had moderate symptoms, 7.5% had severe symptoms and one child died. Where incidents involved the old formulation very few patients escaped without symptoms and over 50% of thm had skin burns or moderate systemic symptoms. With the new formulation over 50% of the patients were asymptomatic and skin burns were uncommon. However there was no significant difference in the incidence of severe systemic symptoms between the formulations. The new formulation appears safer when small amounts of the fluid are ingested, but when larger amounts are involved it is potentially lethal. The case history of the fatal poisoning is presented.