kitchen sink

The EPA released yesterday lifetime drinking water health advisories for perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA).

It set each benchmark at 0.07 microgram per liter or 70 parts per trillion.

You may be familiar with the acronyms PFOS and PFOA. These chemicals have received a lot of attention in recent months with various incidents of localities identifying problems with PFOA or PFOS drinking water contamination. Think Hoosick, N.Y., for one.

But let’s get specific for a minute.

These chemicals were previously widely used in products like carpets to make them more water- or stain-resistant, and certain exposure could result in negative health effects including cancer.

Neither chemical is widely manufactured in the U.S. anymore. PFOS was largely phased out in the early 2000s by primary manufacturer 3M. DuPont (the primary manufacturer of PFOA) has stopped its manufacturing of PFOA. PFOA and PFOA-related chemicals are still used for limited purposes.

However, both chemicals are highly persistent. That means that once those chemicals are released into the environment and the human body, they are very difficult to break down. So even though new releases of these chemicals and overall exposure has decreased, exposure is still an issue.

For drinking water, exposure is mostly limited as an issue for communities where supplies have been contaminated around a specific PFOS or PFOA-manufacturing or using facility, such as an airfield where the chemicals were used in firefighting efforts.

Back to the EPA’s announcement yesterday, though.

The lifetime health advisories released by the EPA yesterday are intended to offer a guideline for determining whether the concentrations of chemicals in tap water are safe for public consumption.

For states, congressmen and others, the advisories bring welcomed guidance on how to protect the public. They have been dealing with the issue for years but the agency hadn’t updated its provisional short-term health advisories on the issue since January 2009.

And the EPA did make changes to those guidelines: The EPA had previously said concentration levels in drinking water of 0.4 microgram per liter (400 parts per trillion) of PFOA and of 0.2 microgram per liter (200 parts per trillion) of PFOS were safe. The new advisory significantly reduced those levels.

Reactions to the new levels are mixed. Depending who is asked, the numbers reached by the EPA for the lifetime health advisories are very protective—or up to 70 times too high.

These advisories aren’t the end of the issue, though.

The EPA left the option open to develop enforceable rules on the chemicals at a later time.