Hydrogen Sulfide Gas (H2S)

09-21-20 03:00 PM Comment(s)

"The Rotten Egg"

Ball & Stick Model

Common Name(s):

Sewer Gas, Stink Damp, Swamp Gas, Manure Gas


Carl Wilhelm Scheele (Sweden); 1777


None - the gas is colorless


Rotten eggs


Yes (range 4.3% - 46% atmosphere)

OSHA Permissible Exposure Limit (PEL):

10 Part Per Million (8 hr. time weighted average)


20 Part Per Million; 50 Part Per Million (10 min. max peak)

Route of Exposure:

Inhalation is the main route of exposure. Absorption through the skin is minimal.

Toxicity Levels PPM:

0.00047 ppm or 0.47 ppb is the odor threshold, the point at which 50% of a human panel can detect the presence of an odor without being able to identify it.
10 ppm is the OSHA permissible exposure limit (PEL) (8 hour time-weighted average).
10–20 ppm is the borderline concentration for eye irritation.
20 ppm is the acceptable ceiling concentration established by OSHA.
50 ppm is the acceptable maximum peak above the ceiling concentration for an 8-hour shift, with a maximum duration of 10 minutes.
50–100 ppm leads to eye damage.
At 100–150 ppm the olfactory nerve is paralyzed after a few inhalations, and the sense of smell disappears, often together with awareness of danger.
320–530 ppm leads to pulmonary edema with the possibility of death.
530–1000 ppm causes strong stimulation of the central nervous system and rapid breathing, leading to loss of breathing.
800 ppm is the lethal concentration for 50% of humans for 5 minutes' exposure.
Concentrations over 1000 ppm cause immediate collapse with loss of breathing, even after inhalation of a single breath.

How to detect H2S gas:

H2S Detector, 4 Gas Meter

Where can H2S be found?:

Crude Oil Production, Natural Gas, Various Refineries, Volcanoes/Vents, Hot Springs, Sewer Systems, Wetland Areas, Animal Waste, Waste Water Treatment, Landfills, Human Intestines (small amounts), Human Mouth (Halitosis; small amounts) - in all these places the gas will hover just over the ground because it is heavier than air.

Downloadable H2S Safety Data Sheet