Odor threshold (when rotten egg smell is first noticeable to some). Odor becomes more offensive at 3-5 ppm. Above 30 ppm, odor described as sweet or sickeningly sweet.

Hydrogen sulfide (also known as H 2 S, sewer gas, swamp gas, stink damp, and sour damp) is a colorless gas known for its pungent "rotten egg" odor at low concentrations. It is extremely flammable and highly toxic.

Hydrogen Sulfide (H 2S) Hydrogen sulfide is a colorless, flammable, extremely hazardous gas with a “rot-ten egg” smell. Some common names for the gas include sewer gas, stink damp, swamp gas and manure gas. It occurs naturally in crude petroleum, natural gas, and hot springs. In addition, hydrogen sulfide is produced by bacterial break-

DO NOT rely on your sense of smell to indicate the continuing presence of hydrogen sulfide or to warn of harmful levels. You can smell the "rotten egg" odor of hydrogen sulfide at low concentrations in air.

0.01-1.5 Odor threshold – rotten egg smell. 10 Permissible Exposure Level – 8 Hours. 20 -30 Possible fatigue, loss of appetite, headache, irritability, poor memory, dizziness.

H2S is a colorless, flammable, and corrosive gas with an odor similar to rotten eggs. People can lose their ability to smell H2S, even at low concentrations, a condition called olfactory fatigue. Because of olfactory fatigue, OSHA warns that the sense of smell should not be used as a detection method. According to the National Institute for

Hydrogen Sulfide (H 2S) Hydrogen sulfide is a colorless, flammable, extremely hazardous gas with a “rotten egg” smell. It occurs natu-rally in crude petroleum and natural gas, and can be pro-duced by the breakdown of organic matter and human/ animal wastes (e.g., sewage). It …

Hydrogen sulfide is included in these lists of toxic and reactive highly hazardous chemicals and is considered to present a potential for a catastrophic event at or above 1500 pounds.

Never rely on sense of smell for the presence of H 2 S. The toxic hazards associated with H 2 S exposure are serious at well sites. Many fatalities have occurred.

In general, working in the following areas and conditions increases a worker’s risk of overexposure to hydrogen sulfide: Confined spaces (for example pits, manholes, tunnels, wells) where hydrogen sulfide can build up to dangerous levels. Windless or low-lying areas that increase the potential for pockets of hydrogen sulfide to form.