Sources of H2S

H2S, also referred to as hydro sulfuric acid, stink damp and sewer gas, has several different sources and can be found in the natural environment, within the human body, in the home or in anthropogenic environments such as the petroleum or pulp and paper industries. The main focus of the H2S Alive program provided through Enform and offered at Calgary First Aid is how the H2S gas is found in the petroleum and natural gas workplace. The course will also cover the proper safety procedures, detection methods and management of situations where the gas is present in low and high concentrations. Before learning to manage scenarios of concentrations of H2S it is important to understand the sources of this gas. The main focus of this page is to outline all of the major and minor sources of Hydrogen Sulfide throughout the world.

Natural Occurrences

Organic Decomposition

Hydrogen Sulfide is naturally found as anaerobic (without oxygen) bacteria decomposes organic material. This is why it is present in swamp and sewer environments where decomposition of bacteria is occurring anaerobically. This is why these areas emit the odours that we often smell.

Geomorphology and Chemical Reactions

Other natural environments where the gas is present include volcanoes and other and other areas of active natural geomorphology. They can be found emanating from hot springs and in harsh environments such as underwater sub-sea vents. Furthermore, hydrogen sulfide arises virtually anywhere where elemental sulfur comes in contact with organic material, especially at high temperatures

Within the Human Body

H2S is also present in the human body in extremely small quantities. The bacterial activity inside of our body creates this gas as well as the neurotransmission components. Because it naturally occurs within our bodies we are able to manage low level’s of H2S and naturally and infinitely process it. However, above a certain threshold H2S can wreak havoc throughout the body.

Anthropogenic Caused Occurences

In the anthropogenic (man-made) environment H2S can be found in a number of different industries. It is present in the farming, coal mining, pulp and paper, tanning and smelting industries. Smelting activities arguably make up 10% of the total worldwide emissions.

In the Modern Home

H2S gas can also be found in homes with poor plumbing. Anaerobic decomposition can occur within homes with sewer drains with dry traps.

Petroleum and Gas Industry

The largest industrial cause of H2S is through petroleum refineries as the hydroesulfiruization process liberates Sulfur from petroleum. Other sources include the decomposition of organic materials such as lignosulfonates in drilling fluids. Small amount of hydrogen sulfide occur in crude petroleum. Natural gas can con contain up to 90% H2S.

The main focus of H2S training is for individuals working in the petroleum industry where safety concerns with this toxic gas are high. Because of the toxicity of this gas and the probability of being exposed to toxic levels many individuals that work in the petroleum and or refinery industries are required to take H2S Alive courses.


It is important for individuals who plan on attending H2S safety courses to know the common sources of H2S gases. This information is vital to learning proper safety procedures and management skills in the event high concentrations of H2S are found in an area. For more information about H2S safety check out our other pages found underneath the H2S Alive heading or take a H2S course with us in one of our training facilities in Calgary.