To examine the public health consequences of acute hazardous substance releases resulting from the improper mixing of chemicals.
Data from the Agency for Toxic Substances and Disease Registry’s Hazardous Substances Emergency Events Surveillance system for 1996–2001 events were analyzed.
“Private households” was the most frequent industry classification among improper mixing events, and chlorine was associated with a greater prevalence of improper mixing events. Releases from improper mixing were considerably more likely to involve fire, explosion, and fire–explosion combined; were markedly more likely to result in personal injury (48% for improper mixing events vs. 7% other events); and had a significantly greater percentage of victims with traumatic injury (PR = 3.07, 95% CI = 2.55–3.71).
Improper chemical mixing can cause dangerous, harmful reactions and are preventable. Consumers should be educated to avoid mixing noncompatible products.