Chloroform
Chloroform is the most common trihalomethane and the surrogate the NSF/ANSI 53 VOC test uses for the family. It is regulated as part of total trihalomethanes (TTHM limit 80 ppb). Its EPA health goal (MCLG) is 0.07 mg/L.
EPA MCLG
0.07 mg/L
The level in drinking water below which there is no known or expected risk to health. This is a goal, not an enforceable limit.
Health Effects
Long-term exposure is associated with an increased risk of bladder cancer at the population level; the EPA and IARC classify it as a possible or probable human carcinogen. Liver, kidney, and central-nervous-system effects have been observed at high doses. The risk is chronic and lifetime, not acute.
Common Sources
- Byproduct of disinfecting drinking water with chlorine
- Formed when chlorine reacts with natural organic matter such as decaying leaves, runoff, and algae
- Levels are highest in warm-season surface water
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Where is Chloroform Found?
Chloroform has been detected above EPA health guidelines in 1,113 cities serving 28.9M people across the US.
and 1,108 more cities
About the EPA MCLG
The EPA MCLG is the level of a contaminant in drinking water below which there is no known or expected risk to health. It is a non-enforceable public health goal, and is often stricter than the legal limit (MCL) water systems must meet.
Contaminant Type
Chloroform is classified as a Disinfection Byproducts contaminant.
Related Disinfection Byproducts Contaminants
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