EPA legal limit
5 ppb
Maximum Contaminant Level
EWG health guideline
0.1 ppb
Science-based, stricter target
IARC classification
Group 2A
Cancer research classification
Health effects
Classified as a probable human carcinogen (IARC Group 2A). Associated with kidney cancer and non-Hodgkin's lymphoma in occupational studies. Neurological effects at high exposures. The EPA MCL of 5 ppb is 50× higher than the EWG health guideline of 0.1 ppb.
Where it comes from
Dry cleaning facilities, metal degreasing operations, and industrial manufacturing. PCE is dense and sinks in groundwater, making contaminated aquifers difficult to remediate. Found at elevated levels near dry cleaners and industrial sites.
How it's regulated
EPA MCL of 5 ppb. EWG health guideline of 0.1 ppb based on cancer risk. Listed as a priority contaminant under the Safe Drinking Water Act.
The EPA vs EWG gap
The legal limit (5 ppb) is 50× higher than the EWG health guideline (0.1 ppb). Water can be legally compliant while still exceeding the science-based threshold.
How to filter tetrachloroethylene
Not all filters address tetrachloroethylene. Look for independently certified filters—NSF International certification means the removal claim has been independently verified.
Frequently asked questions
What is tetrachloroethylene?
An industrial solvent also known as perchloroethylene (PERC). Widely used in dry cleaning and metal degreasing operations. One of the most common groundwater contaminants at industrial and dry-cleaning sites.
What are the health effects of tetrachloroethylene?
Classified as a probable human carcinogen (IARC Group 2A). Associated with kidney cancer and non-Hodgkin's lymphoma in occupational studies. Neurological effects at high exposures. The EPA MCL of 5 ppb is 50× higher than the EWG health guideline of 0.1 ppb.
Is tetrachloroethylene regulated in drinking water?
EPA MCL of 5 ppb. EWG health guideline of 0.1 ppb based on cancer risk. Listed as a priority contaminant under the Safe Drinking Water Act.
Where does tetrachloroethylene come from?
Dry cleaning facilities, metal degreasing operations, and industrial manufacturing. PCE is dense and sinks in groundwater, making contaminated aquifers difficult to remediate. Found at elevated levels near dry cleaners and industrial sites.
How do I remove tetrachloroethylene from tap water?
The most effective methods for removing tetrachloroethylene are: Activated carbon block filter, NSF 53 certified filter, Reverse osmosis (RO), NSF 58 certified RO system. Look for NSF-certified systems—independent certification confirms removal claims have been verified.
Is tetrachloroethylene in your water?
Enter your ZIP code to see the measured level in your specific utility.