EPA legal limit
No federal limit
Maximum Contaminant Level
EWG health guideline
0.4 ppb
Science-based, stricter target
IARC classification
Group 2B — possibly carcinogenic to humans
Cancer research classification
Health effects
MBAA is acutely toxic at high concentrations. It has shown genotoxic activity (DNA damage) in multiple test systems, which is the basis for the EWG health guideline. Longer-term reproductive and developmental effects have been observed in animal studies. IARC has classified it as a possible human carcinogen (Group 2B).
Where it comes from
Formed during chlorination of water containing bromide. Found at lower concentrations than DBAA in high-bromide water and is less prevalent than DCA or TCA in typical US water supplies. Often detected alongside other brominated HAA compounds.
How it's regulated
No individual EPA MCL — regulated within the HAA5 group limit of 60 ppb. EWG health guideline: 0.4 ppb, based on genotoxicity data. Typically a smaller fraction of total HAA5 than DCA or TCA.
How to filter monobromoacetic acid
Not all filters address monobromoacetic acid. Look for independently certified filters—NSF International certification means the removal claim has been independently verified.
Frequently asked questions
What is monobromoacetic acid?
Monobromoacetic acid (MBAA) is one of the five HAA5 compounds, containing a single bromine atom. It is typically found at low to moderate levels in chlorinated water supplies with bromide present in source water. MBAA is also an intermediate in the formation of more halogenated HAA compounds.
What are the health effects of monobromoacetic acid?
MBAA is acutely toxic at high concentrations. It has shown genotoxic activity (DNA damage) in multiple test systems, which is the basis for the EWG health guideline. Longer-term reproductive and developmental effects have been observed in animal studies. IARC has classified it as a possible human carcinogen (Group 2B).
Is monobromoacetic acid regulated in drinking water?
No individual EPA MCL — regulated within the HAA5 group limit of 60 ppb. EWG health guideline: 0.4 ppb, based on genotoxicity data. Typically a smaller fraction of total HAA5 than DCA or TCA.
Where does monobromoacetic acid come from?
Formed during chlorination of water containing bromide. Found at lower concentrations than DBAA in high-bromide water and is less prevalent than DCA or TCA in typical US water supplies. Often detected alongside other brominated HAA compounds.
How do I remove monobromoacetic acid from tap water?
The most effective methods for removing monobromoacetic acid are: Activated carbon block filter, NSF 53 certified filter, Reverse osmosis (RO). Look for NSF-certified systems—independent certification confirms removal claims have been verified.
Is monobromoacetic acid in your water?
Enter your ZIP code to see the measured level in your specific utility.