What are the dangers of breathing sewer gas?

Written by angus koolbreeze | 13/05/2017
What are the dangers of breathing sewer gas?
Sewer gas may be colourless and odourless, but it is dangerous. (Sewer Lid Symmetry image by Tinu from Fotolia.com)

If you notice a smell in your house that resembles rotten eggs, something is amiss with your sewage system. Take it seriously and call a plumber. In addition you should call a doctor, as you may have incurred exposure to a chemical that is life-threatening. Indeed, hydrogen sulphide, or sewer gas, can have deleterious effects on your health. According to the Wetanddamp website, even if the stench does subside after 15 or 20 minutes, it is no less dangerous.


Hydrogen sulphide, or sewer gas, is flammable. According to the Occupational Health and Safety website, when the gas mixes with air, it can explode, causing a flashback. Also, it could cause the release of sulphur dioxide, a highly toxic chemical, into the atmosphere. The website further states that high concentrations can cause complications such as shock, convulsions and even death within just a few short inhalations.

Causes Olfactory Fatigue

You can be exposed to sewer gas and not even know it. If your exposure rate is high enough, the gas can dull your olfactory nerves, and you can inhale the toxic gas without even knowing it.

Affects Blood Oxygen Levels

According to the Andrewweil website, if exposure to sewer gas is high enough, it could affect the blood's ability to carry oxygen throughout the body. With high enough concentrations, it could cause death from suffocation due to oxygen deprivation in your bloodstream.


According to the OSHA website, even low concentrations of the gas can act as an irritant to the eyes, nose, throat and respiratory system as a whole. It can, for example, cause a serious cough, headache, and/or dizziness. These symptoms can come as delayed reactions, emerging hours after exposure. Prolonged and repeated exposures can only serve to intensify these reactions.

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