Hydrogen Sulfide Gas- what you need to know

What is Hydrogen Sulfide gas?

Hydrogen Sulfide gas (also spelled Hydrogen Sulphide gas in UK English) is a poisonous gas that is found naturally in many places such as marshes, forested areas having decaying organic matter, sewage pipelines, garbage dumps, oilfields, gas fields and such places. It has the molecular formula H2S.

H2S gas is also a byproduct of some processes and therefore is present in many chemical plants, petroleum refineries, gas processing units, pharmaceutical manufacturing plants, coke ovens, waste water plants and paper mills, to name a few. It is more common in industry than what you may believe.

In the oil and gas industry, any gas that has significant amount of H2S in it is called as sour gas.

Why is Hydrogen Sulfide gas dangerous?

Hydrogen Sulfide gas is highly dangerous to not only humans, but also any living animal. It can quickly result in death of the victim. The danger is that  smaller H2S concentrations can be smelled by humans very well (it has an odor similar to rotten eggs) and is highly noxious. However, as the concentration increases, olfactory cells in a human nose get desensitized and the victim stops noticing the smell!

This results in victims thinking that the danger has passed, when in fact what has happened in reality is that their ability to sense it got highly diminished. This has resulted in individuals suddenly crashing to ground, unconscious.

What could be a dangerous concentration of H2s?

The Threshold Limit Value (TLV) of H2S is considered to be 1 ppm (one part per million). The STEL (Short Term Exposure Limit) is considered to be 5 ppm. Anything above this could be fatal.

What are other dangers of Hydrogen Sulfide?

Hydrogen Sulfide gas is not only just toxic, it is also explosive. So any area that has the possibility of H2S, should also be classified as a Hazardous Area and only suitable explosion protected equipment should be used in such areas. The Lower Explosive Limit (LEL) of H2S is just 4.6% in air and the Upper Explosive Limit (UEL) of H2S is 45.6% in air. Therefore any concentration between these limits is considered to be an explosive mixture.

How can one protect oneself in a place which could have the presence of H2S gas?

First of all, you should always be aware of the dangers of Hydrogen Sulfide gas, while working in any area that could have the possibility of H2S gas being present.This includes areas that have sour gas present, such as in many oilfields and natural gas fields or natural gas processing plants.

Secondly you should always carry pocket H2S gas monitors that will alert you in case any H2S is detected. You should immediately stop whatever work you are carrying out and exit the area or call for help. Be aware that in the presence of H2S, only a person wearing proper Personal Protective Equipment (PPE), Respiratory protection and a Self Contained Breathing apparatus can work or be engaged in any rescue operation.

Where can I learn more about H2S?

Take the Abhisam free H2S training course online now and be aware of H2S and its dangers. There is an optional H2S certificate that you can get after having taken the course and passed the associated exam.

What about getting an H2S awareness certificate?

Many employers who have work areas that could have H2S presence require all employees to take H2S training. You can take the free Abhisam H2S Course online from the Abhisam Learning Portal. If you wish you can order the H2S certificate, which is optional.

We are a company and wish to have H2S awareness training. How do we do this?

Contact us to enable all your employees to take the Abhisam Hydrogen Sulfide gas awareness training course on the Abhisam Learning Portal. You can get detailed training records in the form of a dashboard if you have more than 50 employees. This course can de deployed so that hundreds of employees can take it.