Haloacetic Acids (HAA5)
Category: disinfection byproduct
EPA MCL
0.06 mg/L
Status
EPA Regulated
NSF Standard
NSF/ANSI 53
Health Effects
Increased cancer risk with long-term exposure. Some haloacetic acids are classified as probable or possible human carcinogens. Also associated with reproductive and developmental effects in animal studies.
Where It Comes From
Formed when chlorine or other disinfectants react with natural organic matter in source water. The five regulated HAAs are monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid.
Where It's Commonly Found
All chlorinated water systems. Higher levels in surface water systems with high organic content. Levels vary seasonally and with distance from the treatment plant.
Found in virtually all chlorinated water systems. EWG health guideline of 0.1 ppb is far stricter than the EPA MCL of 60 ppb. Thousands of systems exceed EWG's recommended levels.
How to Remove It
Effective Technologies
- activated carbon
- carbon block
- reverse osmosis
Does NOT Remove It
- UV
- ion exchange
- water softener
- mechanical filtration
- ceramic
Official Sources
Related Contaminants
Learn More
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Enter Your ZIP Code →Informational guidance based on EPA data and NSF standards - not medical advice.