Top five chemicals resulting in injuries from acute chemical incidents—Hazardous Substances Emergency Events Surveillance, nine states, 1999-2008.

Problem/condition: The Toxic Substances Control Act Chemical Substance Inventory lists >84,000 chemicals used in commerce (http://www.epa.gov/oppt/existingchemicals/pubs/tscainventory/basic.html). With chemicals having a multitude of uses, persons are potentially at risk daily for exposure to chemicals as a result of an acute chemical incident (lasting <72 hours). Depending on the level of exposure and the type of chemical, exposure can result in morbidity and, in some cases, mortality.

Reporting period: 1999-2008.

Description of system: The Hazardous Substances Emergency Events Surveillance (HSEES) system was operated by the Agency for Toxic Substances and Disease Registry during January 1991-September 2009 to collect data that would enable researchers to describe the public health consequences of chemical incidents and to develop activities aimed at reducing the harm from such incidents. This report identifies the top five chemicals that caused injuries in the nine states (Colorado, Iowa, Minnesota, New York, North Carolina, Oregon, Texas, Washington, and Wisconsin) that participated in HSEES during its last 10 full years of data collection (1999-2008).

Results: Of the 57,975 incidents that were reported, 54,989 (95%) involved the release of only one chemical. The top five chemicals associated with injury were carbon monoxide (2,364), ammonia (1,153), chlorine (763), hydrochloric acid (326), and sulfuric acid (318). Carbon monoxide and ammonia by far caused the most injuries, deaths, and evacuations. Chlorine, while not in the top 10 chemicals released, was in the top five chemicals associated with injury because of its hazardous properties.

Interpretation: Multiple measures can be taken to prevent injuries associated with the top five chemicals. Because many carbon monoxide releases occur in residential settings, use of carbon monoxide detectors can prevent injuries. Substituting chemicals with less lethal alternatives can result in mitigating injuries associated with ammonia. Routine maintenance of equipment and engineering controls can reduce injuries associated with chlorine and sulfuric acid, and proper chemical handling training can reduce injuries associated with hydrochloric acid. PUBLIC HEALTH IMPLICATIONS: Understanding the most frequently reported locations where carbon monoxide, ammonia, chlorine, hydrochloric acid, and sulfuric acid are released along with the most frequently reported contributing factors can help mitigate injuries associated with these releases. Prevention initiatives should focus on educating the public and workers about the dangers of these chemicals and about proper handling of these chemicals along with routine maintenance of equipment.