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Chemical Suicides in Automobiles --- Six States, 2006--2010

During a 3-month period in 2008 in Japan, 208 persons committed suicide by mixing household chemicals and, while in a confined space, breathing in the resultant poisonous gas (1). The large number of similar suicides is believed to have resulted from the posting of directions for generating poisonous gas on the Internet (1--3). In addition to claiming the suicide victim, lethal gas generated by intentionally mixing household chemicals can leak from confined spaces, triggering evacuations, and exposing bystanders and first responders to injury (2). Chemical suicides similar to those in Japan in 2008 have been reported increasingly in the United States, with the majority occurring inside automobiles (3). To characterize such incidents in the United States, the Agency for Toxic Substances and Disease Registry (ATSDR) analyzed reports of chemical suicides and attempted suicides that occurred in automobiles, using 2006--2009 data from states participating in the Hazardous Substances Emergency Events Surveillance (HSEES) system and 2010 data from states participating in the new National Toxic Substance Incidents Program (NTSIP). This report summarizes the results of that analysis, which found that, during 2006--2010, a total of 10 chemical suicide incidents were reported from six states, resulting in the deaths of nine suicide victims and injuries to four law enforcement officers. When responding to suspected chemical suicide incidents, emergency responders must take precautions to ensure both their safety and the safety of any bystanders in the immediate vicinity.

Fifteen states conducted surveillance for acute hazardous substance releases at some time during 2006--2010. An average of 13 of the states participated in HSEES* during 2006--2009, and nine states (two unfunded) participated in NTSIP during 2010, the first year of the program. ATSDR uses these surveillance systems to track the public health consequences from acute hazardous materials (HazMat) releases. State health departments obtained data from multiple sources, including state environmental agencies, police and fire departments, poison control centers, hospitals, local media, the U.S. Coast Guard's National Response Center, and the U.S. Department of Transportation's Hazardous Material Incident Reporting System. Both HSEES and NTSIP define a hazardous substance as one that might reasonably be expected to cause adverse health effects in humans. For this analysis, to find potential suicide incidents, open text fields were queried in the comments and synopsis sections of HSEES and NTSIP databases for the following terms: "kill," "die," "death," "intentional," "suicide," "car," "vehicle," "truck," and "auto." A case was defined as a suicide or attempted suicide using mixed chemicals in an automobile. Case reports were read to confirm that the suicide took place inside an automobile and chemicals were mixed.

Ten incidents of chemical suicide or attempted suicide in automobiles were reported: one in 2006, one in 2007, four in 2009, and four in 2010. The 10 incidents occurred in six states (Connecticut, Florida, New York, North Carolina, Utah, and Washington) and resulted in nine deaths of suicide victims (one person began a suicide attempt but aborted the effort) and injuries to four law enforcement officers who arrived on the scene. Two of the law enforcement officers experienced respiratory irritation; symptoms were not available for the other two. None of the four law enforcement officers wore personal protective equipment; however, two had received HazMat training.

Of the 10 incidents, nine occurred in residential areas and four resulted in evacuation orders affecting 85 persons. Thirty-two persons were decontaminated. In addition to household cleaners (not otherwise specified), the following chemicals were used in the 10 incidents: ammonium hydroxide, aluminum sulfide, calcium hypochlorite, calcium sulfide, germanium oxide, hydrochloric acid, potassium ferrocyanide, sodium hypochlorite, sulfur, sulfuric acid, and trichloroethylene.

Among the six victims for whom exact age was known, the median age was 31 years (range: 22--69 years); among the other four victims, two were aged <18 years, and two were aged ≥18 years. Seven of the 10 victims were male.

Illustrative Case Reports

North Carolina. In 2010, a "detergent suicide" victim was found deceased in a vehicle. A bucket inside the vehicle contained mixed chemicals that caused acute thiosulfate poisoning. Two law enforcement officers were exposed, one of whom was treated at the hospital. Local emergency responders evacuated the surrounding homes. The regional response team removed and decontaminated the corpse of the suicide victim before transporting it to the medical examiner.

New York. In 2009, a hiker in a park found a car posted with signs warning of toxic gas and called 911. Inside the car, responders found a deceased person and two buckets of mixed chemicals. A HazMat team, sheriff's deputies, and the medical examiner responded as well. The sheriff's deputies evacuated hikers and residents within a half-mile of the scene. Some responders had consulted with a nearby county and used techniques learned during a similar HSEES incident that had occurred a few days earlier. Responders vented the car before decontaminating the body. The body was then double-bagged and, to protect the driver, transported by law enforcement officers in the open bed of a pickup truck. Ten HazMat team members and two nearby vehicles were decontaminated at the scene. A hazardous waste disposal service was contracted to remove the chemicals and decontamination fluids for disposal.

Reported by

Jennifer L. McNew, Sherry G. Rigouard, MPH, North Carolina Div of Public Health, Wanda L. Welles, PhD, Rebecca Wilburn, MPH, New York State Dept of Health. Ayana R. Anderson, MPH, Maureen F. Orr, MS, D. Kevin Horton, DrPH, Div of Health Studies, Agency for Toxic Substances and Disease Registry. Corresponding contributor: Ayana R. Anderson,, 770-488-3906.

Editorial Note

Suicide is the 11th leading cause of death in the United States and the third leading cause among persons aged 15--34 years, accounting for 9,418 deaths in this age group in 2007.§ During National Suicide Prevention Week, September 4--10, CDC is encouraging health-care providers, public health practitioners, and others to learn more about strategies for preventing suicide and the availability of the 24-hour National Suicide Prevention Lifeline.**

This analysis of chemical suicides in automobiles was limited to an average of 13 states that participated in HSEES and nine states (two unfunded) that participated in NTSIP during 2006--2010 and identified 10 cases during that 5-year period. The only other published report of chemical suicides in the United States reported 75 chemical suicides during 1999--2010. That report, which identified incidents by using the National Vital Statistics System, the National Association of Medical Examiners listserv, and Google searches, found that, of 30 incidents reported during 2008--2010, two occurred in 2008, 10 in 2009, and 18 in 2010. Of the 30 incidents, 24 (80%) occurred in cars (3).

In this report, two law enforcement officers were injured because they entered the suicide vehicles without adequate personal protective equipment or ventilation. Officers and other responders need to be informed about precautions they must take when responding to a potential chemical suicide. When initially arriving on the scene of a suspected chemical suicide, responders should assess the surroundings for potential indicators (e.g., posted suicide or warning signs, open containers indicating the presence of household chemicals, and taped doors and windows) (4). Once a proper assessment of the scene has been made, responders should call for assistance from the local HazMat team or other responders who are trained to handle hazardous materials. In addition to assessing the surroundings, first responders can secure the area by ensuring nearby persons are safe and keeping ignition sources away (5,6). First responders always should protect themselves and follow appropriate HazMat guidelines (5,6) to address the situation.

The toxic gases most commonly formed by combining the chemicals in household cleaners are hydrogen sulfide and hydrogen cyanide (4). Hydrogen sulfide is a colorless, toxic gas. Its odor is often described as that of rotten eggs, but even a short exposure can cause olfactory fatigue (i.e., a temporary inability to smell the gas) (1,4). At low doses, exposure to hydrogen sulfide can cause eye and respiratory irritation, headache, dizziness, loss of appetite, and upset stomach (1,2,4). Brief exposures to high concentrations (>500 ppm) of hydrogen sulfide can cause loss of consciousness and death (7). Hydrogen cyanide is a bluish-white liquid or a colorless gas with a faint odor of bitter almonds and a bitter, burning taste (8,9). Hydrogen cyanide can cause changes in respiration depth, confusion, and asphyxia (4).

The findings in this report are subject to at least three limitations. First, because only a total of 15 states conducted surveillance at some time during 2006--2010 (in HSEES, NTSIP, or in both programs), the data might not be generalizable to the entire United States. Second, the number of chemical-assisted suicides described likely is an underestimate because some suicides might not have been reported or might have been missed by the query method of key word searches. Finally, the small number of incidents identified by ATSDR complicates evaluation of chemical suicide trends in the United States.

When handling chemically contaminated victims, safety precautions must be taken to prevent secondary contamination via transfer of hazardous materials (e.g., off-gassing) from victims to bystanders or emergency responders (10). Both victims and responders should be decontaminated at the scene to prevent further chemical-related injuries (4). Additionally, the transport vehicle needs to be well ventilated to protect from accumulation of poison off-gassing from the victim (6,7). Additional measures include warning hospital personnel of the potential for exposure and calling in the local HazMat team. Wearing the appropriate protective gear, the local HazMat team can assist with decontamination and preventing the chemical release from spreading (Box).


  1. Morii D, Miyagatani Y, Nakamae N, Murao M, Taniyama K. Japanese experience of hydrogen sulfide: the suicide craze in 2008. J Occup Med Toxicol 2010;5:28.
  2. Truscott A. Suicide fad threatens neighbours, rescuers. CMAJ 2008;179:312--3.
  3. Reedy SJ, Schwartz MD, Morgan BW. Suicide fads: frequency and characteristics of hydrogen sulfide suicides in the United States. West J Emerg Med 2011;12:300--4.
  4. National Hazardous Materials Fusion Center. Chemical assisted suicide: responder information. Available at Accessed September 1, 2011.
  5. US Fire Administration. Hazardous guidelines for first responders. Emmitsburg, MD: Federal Emergency Management Agency, US Fire Administration; 1998.
  6. US Department of Transportation. 2008 emergency response guidebook. Washington, DC: US Department of Transportation; 2008.
  7. Agency for Toxic Substances and Disease Registry. Toxic substance portal: medical management guidelines for hydrogen sulfide. Atlanta, GA: Agency for Toxic Substances and Disease Registry; 2011. Available at Accessed September 1, 2011.
  8. National Institute for Occupational and Safety Health. NIOSH pocket guide to chemical hazards. Atlanta, GA: US Department of Health and Human Services, CDC, National Institute for Occupational and Safety Health; 2009. Available at Accessed September 2, 2011.
  9. Agency for Toxic Substances and Disease Registry. Toxic substance portal: hydrogen cyanide. Atlanta, GA: Agency for Toxic Substances and Disease Registry; 2011. Available at Accessed September 2, 2011.
  10. Horton DK, Berkowitz Z, Kaye WE. Secondary contamination of ED personnel from hazardous materials events, 1995--2001. Am J Emerg Med 2003;21:199--204.

* Additional information available at

Additional information available at

§ Available at

Available at

** Additional information available at

What is already known on this topic?

Mixing household chemicals to create lethal levels of toxic gas in a confined space became a popular method of suicide in Japan, and similar suicides have been reported by the news media in the United States; however, little data have been collected systematically.

What is added by this report?

Surveillance data from 15 states during 2006--2010 identified 10 incidents of chemical suicides in automobiles, resulting in nine deaths to suicide victims and four injuries to law enforcement officers.

What are the implications for public health practice?

First responders, health-care providers, and others who might encounter chemical suicides or attempted suicides should be able to recognize them. Protective measures should be used in these situations to prevent injury or death among responders and bystanders.

BOX. Precautions for emergency responders at the scene of suspected chemical suicide incidents

Survey surroundings of scene and vehicle

  • Search the area or the vehicle's exterior for posted or visible warning signs.

  • Look for open containers or a mixing container.

  • Look for attempts to seal the vehicle, such as taping of doors, windows, and air vents.

  • Do NOT rely on the presence of a chemical or unusual odor as a warning signal.

Secure the area

  • If gas is emitting from the vehicle, first responders should stay upwind.

  • Keep bystanders away from the scene.

  • Hazardous materials (HAZMAT) team or other responders trained to handle hazardous chemicals can help prevent the spreading of the gas while wearing appropriate protective gear.


  • Call the local HAZMAT team or other responders trained to handle hazardous materials.

  • Ensure dispatch information is shared among all responders to enhance safety.


  • Decontaminate the victim at the scene.

  • Decontaminate all responders and victims involved in the incident.

  • Evaporated gas from the wet clothes of patients can cause secondary poisoning or contamination.

  • Warn hospital personnel to take appropriate measures to avoid contamination of incoming patients.

Transportation and treatment of victim

  • Because hydrogen sulfide and cyanide gases are in patient's exhalations, mouth-to-mouth resuscitation is unsafe.

  • No antidote exists for hydrogen sulfide poisoning; treatment is supportive.

  • Exposure to hydrogen cyanide requires supportive care and rapid administration of specific antidotes.

  • Chemicals off-gassing from the victim might poison emergency medical services, morgue, or other response personnel; therefore, the transport vehicle should be well ventilated.

Sources: National Hazardous Materials Fusion Center. Chemical assisted suicide: responder information. Available at

US Department of Transportation. 2008 emergency response guidebook. Washington, DC: US Department of Transportation; 2008.

Agency for Toxic Substances and Disease Registry. Toxic substance portal: medical management guidelines for hydrogen sulfide. Atlanta, GA: Agency for Toxic Substances and Disease Registry; 2011. Available at

Agency for Toxic Substances and Disease Registry. Toxic substance portal: medical management guidelines for hydrogen cyanide. Atlanta, GA: Agency for Toxic Substances and Disease Registry; 2011. Available at

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