(U//FOUO) Hydrogen sulfide is a colorless, toxic, and flammable gas with a strong odor of rotten eggs at low concentrations. Its odor is not a reliable indicator of its presence, however, because high concentrations or continuous exposure deaden the sense of smell. It can be produced by mixing a sulfur source, such as certain paints and pesticides, with an acid, such as those found in toilet bowl cleaners and disinfectants (see Table 1). The extent of the hazard will depend on the concentration of the reactive sulfur and acid in the tem used.

Lysol® Ready to Use Disinfectant (4–8 percent citric

and hydroxyacetic acid)

Artist oil paints (0–15 percent zinc

sulfide)

Lysol® Toilet Bowl Cleaner (9.5 percent HCl)

Dandruff shampoos (1.0 percent selenium sulfide)

Sno Bol® Toilet Cleaner (15 percent HCl)

Pesticides (5–30 percent calcium polysulfides)

The Works® Toilet Bowl Cleaner (15–25 percent HCl)

Spackling paste (1–2 percent zinc sulfide)

Blu-Lite® Germicidal Acid Bowl Cleaner (20.5 percent phosphoric acid)

Some latex paints (6.6 percent zinc sulfide)

Kaboom® Shower, Tub, and Tile Cleaner (5–7 percent urea-monohydrochloric acid)

Garden fungicides (5-90 percent sulfur)

Tile, stone cleaners (1-30 percent HCl)

UNCLASSIFIED//FOR OFFICIAL USE ONLY

(U) Effects of exposure to hydrogen sulfide include the following:

* (U) Hydrogen sulfide is a byproduct of the decay of organic material and accidental exposure has occurred in situations involving sewage, liquid manure, natural gas, and animal or vegetable matter storage or processing. It also is found at some industrial facilities, such as wastewater treatment plants, petroleum refineries, pulp and paper manufacturers, and plants producing sulfur or sulfuric acid.

(U//FOUO) Inhalation of hydrogen sulfide has become a popular means of committing suicide in Japan and could become more popular in the United States as publicity about these incidents spreads.

— (U) In August 2008, law enforcement and fire units responded to a suicide involving hydrogen sulfide in Pasadena, California. The victim, found dead in his car, had mixed a fungicide and a toilet bowl cleaner in a plastic tray. First responders saw the tray with a "bright blue liquid" in the back seat of the vehicle. The man had placed a note on the car to warn first responders. Investigation indicated that he may have visited one or more of the numerous Japanese websites that provide information on how to commit suicide using hydrogen sulfide.

(U) Firefighters respond to a suicide in Pasadena

— (U) In Japan, press reports indicated that during the first six months of 2008, more than 500 people had killed themselves by inhaling hydrogen sulfide produced by mixing commonly available chemicals. Many of these incidents occurred in vehicles, apartments, or houses.

(U//FOUO) Terrorist training manuals have discussed using hydrogen sulfide gas in an attack. DHS/I&A and the JRIC assess that the chemical reactions described in the manuals are viable and would yield hydrogen sulfide, but no information indicates that a terrorist attack is imminent using this chemical.

— (U//FOUO) The "Mujahideen Poisons Handbook" describes producing hydrogen sulfide gas by reacting sodium sulfide and sulfuric acid.

— (U//FOUO) Another terrorist training manual proposes mixing hydrochloric acid and iron sulfide.

— (U) The discovery of the suicide victim in Pasadena led to the evacuation of several businesses in the immediate area and left bystanders stranded for up to five hours while responders assessed the scene.

— (U) In one incident in Japan, 90 people in an apartment building reportedly were sickened when a teenage girl killed herself in the bathroom of her apartment by mixing household items that produced hydrogen sulfide.

(U) Hydrogen sulfide is a dangerous, easily produced toxic industrial chemical that can cause health hazards at even low concentrations. If the presence of hydrogen sulfide is suspected at an incident site, responders should follow their agencies’ HAZMAT protocols.

[End DHS Bulletin]