>> RELATED: Note on car prompts HAZMAT response, dead woman found inside
Chemical suicides – though a newer phenomenon in the U.S. and relatively rare – are a growing risk to emergency responders, according to the U.S. Department of Health and Human Services’ Office of Emergency Management.
The most common toxic gas used in chemical suicides is hydrogen sulfide, produced using readily available consumer products, according to the Office of Emergency Management.
The Greene County coroner has not confirmed the cause and manner of death for Alexandra Sniezek, who was found deceased in the vehicle.
Also called detergent suicides, the technique appears to have originated in Japan and migrated elsewhere after instructions became available online, according to federal authorities.
In 2014, a man in his 30s took his life in Springfield using the method. The man also left a warning note on his car parked on Mitchell Boulevard. In addition to clearing the area, authorities in that case also told nearby businesses to shut down HVAC systems.
MORE: ‘Chemical suicide’ a first in Clark County
The National Suicide Prevention Lifeline can be reached at 1-800-273-8255.