Trihalomethanes (THMs)

What are Trihalomethanes and Why Are They In My Water?

THM MoleculeTrihalomethanes or THMs are a chemical compound formed when chlorine and other disinfectants react in water with organic and inorganic material in the water. THMs are considered carcinogenic and an environmental pollutant.

THMs are a group of four disinfection by-products; chloroform, bromoform, bromodichloromethane, and dibromochloromethane.

What are the Health Effects of THM Exposure?

While ingestion of THMs is the main way for these pollutants to enter your body, showering and bathing (inhaling and adsorbing through the skin) are the other ways of exposure. Trihalomethanes are carcinogens, a substance directly involved in causing cancer.

Trihalomethane Removal From Drinking Water

Systems and cartridges that contain active carbon are the most effective treatment for the home.

Reverse Osmosis Water Filters Under Sink Water Filters Everpure Systems and Cartridges Granular Activated Carbon Cartridges Ceramic Filter Cartridges & Candles

Look for this seal:

NSF 53 Certified


NSF/ANSI Standard 53: Drinking Water Treatment Units – Health Effects
Overview: Standard 53 addresses point-of-use (POU) and point-of-entry (POE) systems designed to reduce specific health-related contaminants, such as Cryptosporidium, Giardia, lead, volatile organic chemicals (VOCs), MTBE (methyl tertiary-butyl ether), that may be present in public or private drinking water.

Sources of Information on Trihalomethanes


The foregoing information was compiled from the the links listed above.