Total THMs
Group of contaminants that form in drinking water systems when a disinfectant, typically chlorine, reacts with organic matter
Health Guideline Level (HGL)
0.32 ppb
Maximum level that poses minimal health risk based on the latest science
Health Effects
Drinking water standards for total THMs are based on evidence of carcinogenicity in human and animal studies, as well as liver and kidney toxicity observed in animal studies. Individual THMs have been further associated with developmental, immune, spleen, and genotoxicity.
Affected Organs & Systems:
Common Sources
- Chlorine disinfection interacting with naturally occurring organic matter in distribution systems
- Total THMs are usually higher in surface water than groundwater
- The release of agricultural and industrial chemicals may also contribute to total THMs in drinking water
How to Remove It
Water filters certified under the following NSF standards are effective at removing Total THMs:
Health Guideline Level
The HGL represents the maximum level that poses minimal health risk based on the latest scientific research. It's often more protective than federal legal limits.
Contaminant Type
Total THMs is classified as a Disinfection Byproducts contaminant.
This contaminant primarily affects the spleen, developmental, and other systems.
Check Your Water
Find out if Total THMs is in your tap water.
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