Hydrogen sulfide gas, also known as sewer gas, poses an immediate health risk with even trace exposure. Low concentrations of hydrogen sulfide can cause nose, ear, and throat irritation. High concentrations can be deadly.

To keep yourself and your family safe, learn how to spot early signs of sewer gas poisoning, where you’re most likely to encounter the gas, and the long-term effects of sewer gas poisoning.

What Is Hydrogen Sulfide Poisoning?

Hydrogen sulfide is a naturally occurring gas that’s toxic in high concentrations. The gas is readily identifiable by its characteristic “rotten egg” smell.

While hydrogen sulfide is the most abundant compound of the mix, sewer gas tends to include other dangerous compounds, including:

  • Methane
  • Ammonia
  • Carbon dioxide

Hydrogen sulfide poisoning is the result of sewer gas exposure, whether in high concentrations for a short period or, as is more common in residential settings, prolonged exposure in low concentrations. A whiff of foul air isn’t a concern, but if you have any reason to suspect the presence of sewer gas, contact a plumber right away.

What Are the Symptoms of Sewer Gas Poisoning?

Low-concentration symptoms include respiratory issues, watery eyes, and shortness of breath. In some cases, these symptoms may be delayed, which can sometimes make isolating the place of exposure difficult.

 More advanced symptoms from prolonged exposure or higher concentrations include:

  • Headache
  • Dizziness
  • Nausea
  • Vomiting

In higher concentrations, sewer gas can cause shock, convulsions, coma, and death. These concentration levels are primarily limited to industrial settings, such as oil and gas refineries, mining operations, or municipal sewer systems. Hydrogen sulfide is the leading cause of workplace gas inhalation deaths.

Read more: Household Items That Should Never Go Down Your Drain

How Sewer Gas Enters Homes and Businesses

Sewer gas is heavier than air, which means you’re most likely to encounter high levels of gas in low-lying parts of a building, such as floor drains in a basement or crawl space. Plumbers, sanitary workers, and farm workers also encounter sewer gases during the maintenance or cleaning of septic tanks, municipal sewers, or manure storage tanks.

In most cases, residential hydrogen sulfide exposure is caused by:

  • Leaky or cracked pipes – Poorly installed or faulty pipes may leak sewer gas.
  • Blocked air vents – Your home’s ventilation system relies on the steady flow of air from room to room and out of the home, too. Blocked air vents can allow sewer gas to build up within the structure.
  • Clogged plumbing – Clogged pipes contribute to gas build-up and potentially back into your home. In most cases, clogs are caused by debris from toilets and sinks, as well as structural issues within the pipes themselves, such as corrosion.
  • Dry plumbing – Pipes use small amounts of water in the pipe to prevent gas from backing up the pipe. When this “water barrier” dries out, it increases the chances of hazardous gas being released from the sewer system into your home. Water barrier dry out due to lack of use or leaks, in most cases.

Homeowners can mitigate the risk of sewer gas exposure by cleaning floor and sink drains to prevent sewer pipe traps from drying out.

More Reasons to Be Wary Around Sewer Gas

 While hydrogen sulfide is the most abundant compound in the mix, sewer gas tends to include other dangerous compounds. Even in small amounts, these gases cause ear, nose, and throat irritation and impact respiratory health. In higher concentrations, methane is also extremely flammable, adding a fire hazard to the mix.

How to Treat Sewer Gas Poisoning

In most residential cases of sewer gas poisoning, symptoms will subside as soon as the source of exposure is addressed. If you believe you’ve been exposed to hydrogen sulfide, seek medical attention. Then, contact your local Benjamin Franklin Plumbing; we’ll inspect and test your home for leaks and make recommendations for how to resolve the problem.

Call Us for a Safer, Healthier Home from the Pipes Up

The best way to prevent sewer gas in your home is through regular maintenance from a trusted professional.

The licensed plumbers at your local Benjamin Franklin Plumbing offer punctual, preventative drain cleaning and leak inspection services to keep your family safe and your home running smoothly. Find a Benjamin Franklin Plumbing location near you or call 1-877-BEN-1776 today!