PFCs - EPA health advisory

What is a health advisory?
The EPA develops health advisories to provide information about substances that can cause human health effects and are known (or anticipated) to occur in drinking water.
What is the EPA health advisory for PFCs?
To provide Americans, including the most sensitive populations, with a margin of protection from exposure to specific PFCs (PFOA and PFOS) in drinking water, EPA established health advisory levels for both PFOA and PFOS at 70 parts per trillion. When these two substances are found in drinking water, the combined concentrations should be compared with the health advisory level.

There is very limited scientific information on the health effects of other PFCs, such as PFHxS, PFNA and PFBS. In consultation with EPA Region 8, CDPHE is also including PFHpA along with PFOA and PFOS to compare with the health advisory level due to the potential for PFHpA to have similar effects. It is possible that the other PFCs may have health effects similar to PFOA and PFOS, but there is not enough scientific information to be sure at this time. 

Health advisory level =
70 parts per trillion
or 0.07 parts per billion
How much is a part per billion or trillion?
One part per billion = 1 ug/L (microgram per liter)
This amount is equal to:
  • One drop of ink in a backyard swimming pool.
  • One grain of sand in a child's sandbox.
  • One second in 32 years.
One part per trillion = 1 ng/L (nanogram per liter)
This amount is equal to:
  • One drop of detergent in enough dishwater to fill a string of railroad tank cars ten miles long. 
  • One square inch in 250 square miles. 
  • One second in 32,000 years.