EPA legal limit
No federal limit
Maximum Contaminant Level
EWG health guideline
No guideline
Science-based, stricter target
Health effects
Not a health hazard at concentrations found in drinking water. An aesthetic contaminant causing taste and odour issues. Like geosmin, its presence can indicate algal activity in source water.
Where it comes from
Produced by cyanobacteria blooms in reservoirs and lakes. More common in summer months when warm water temperatures promote algal growth. Found in surface water utilities drawing from reservoirs.
How it's regulated
No EPA MCL — unregulated aesthetic contaminant. Managed by utilities through activated carbon treatment and ozonation.
How to filter 2-methylisoborneol
Not all filters address 2-methylisoborneol. Look for independently certified filters—NSF International certification means the removal claim has been independently verified.
Frequently asked questions
What is 2-methylisoborneol?
A musty, camphor-like compound produced by cyanobacteria and actinomycetes bacteria. Along with geosmin, it is one of the two most common causes of musty odour complaints in drinking water. Detectable at extremely low concentrations.
What are the health effects of 2-methylisoborneol?
Not a health hazard at concentrations found in drinking water. An aesthetic contaminant causing taste and odour issues. Like geosmin, its presence can indicate algal activity in source water.
Is 2-methylisoborneol regulated in drinking water?
No EPA MCL — unregulated aesthetic contaminant. Managed by utilities through activated carbon treatment and ozonation.
Where does 2-methylisoborneol come from?
Produced by cyanobacteria blooms in reservoirs and lakes. More common in summer months when warm water temperatures promote algal growth. Found in surface water utilities drawing from reservoirs.
How do I remove 2-methylisoborneol from tap water?
The most effective methods for removing 2-methylisoborneol are: Activated carbon block filter, Granular activated carbon (GAC). Look for NSF-certified systems—independent certification confirms removal claims have been verified.
Is 2-methylisoborneol in your water?
Enter your ZIP code to see the measured level in your specific utility.