Michigan is expanding the breadth of its PFAS scrutiny by considering whether a so-called “safe” replacement chemical carries enough health threat to warrant state officials setting a risk level for exposure.
The Department of Environmental Quality on Dec. 19, 2018, moved FTS 6:2 onto its list of chemicals under review. The process, which focuses on air emissions, means that businesses using the chemical could eventually face new permitting guidelines.
The move signals two changes for the state’s approach to considering per- and poly-fluorinated chemicals.
The first comes from turning potential oversight attention from the legacy contaminants to a form of PFAS that has been marketed by chemical manufacturers as a safer alternative to banned versions.
The second is that, after a year of widespread water testing across the state and tracking PFAS traveling in both ground and surface waters, officials increasingly are considering the role of air transport for the chemicals.
“There are a lot of unknowns related to PFAS and air,” said Mary Ann Dolehanty, director of DEQ’s Air Quality Division.
FTS 6:2 is a fluorotelomer sulfonate used in both AFFF fire-fighting foam and to control surface emissions in the industrial plating industry, in addition to its presence in consumer products like fast-food wrappers. It’s a short-chain fluorinated carbon chemical, which manufacturers like DuPont described as “safe for workers, consumers and the environment” as the longer-chain carbon PFOS and PFOA gained attention for adverse health effects and environmental contamination.
An MLive investigation in fall 2018 shows that high concentrations of PFOS is moving from industry into 15 wastewater treatment plants, and with some eventually getting into Michigan drinking water supplies. While that’s enough to put those plants under DEQ scrutiny due to surface water standards for PFOS, laboratory reports show that FTS 6:2, too, is flowing into surface water from many of the plants. Also present is the chemical that FTS 6:2 breaks down into: PFHxA, another short-chain form of the “forever chemicals.”
Yet while research focuses on the persistence and health effects of PFOS and PFOA – such as cancer, immune disorders and developmental delays in children – less investigation has been done on the replacement chemicals, said Jamie DeWitt, a toxicologist at East Carolina University.
When it comes to FTS 6:2, some research shows it has rapid bioelimination and low toxicity, but it’s also persistent in the environment.
Yet all of that is based on a “very limited number of studies,” DeWitt said.
“It’s in your water, but we know nothing about it,” DeWitt said. “That can be really frustrating because … we don’t have the information to make decisions on our own health.”
That’s accentuated when considering what’s known about how they travel through air.
“We know very little of the atmospheric cycling of PFAS in general,” DeWitt said. “Air circulation may be a very important pathway from the site of emission to remote sites.”
Michigan initiated its Air Quality Division review of the chemical after two Grand Rapids-area plating companies listing the substance on applications for new air permits under the state’s Air Pollution Control Rules. Lacks Enterprises and Allied Finishing listed products containing FTS 6:2 as mist suppressants in their chrome plating baths, said DEQ spokesperson Scott Dean.
The amounts emitted in both cases fall below the exemption limit, Dean said. However, he said, the potential for other businesses to exceed the exemption exists – and there is no screening level set for FTS 6:2 to provide guidance for how much will be allowed in a facility’s emissions.
“Because (FTS 6:2) may have emission rates from some facilities of sufficient quantity to be subject to air requirements,” Dean said, “the AQD decided to review the toxicity data available.”
It’s a start toward considering broader implication, Dean added. And it followed the Air Quality Division inspecting all of the chrome platers in Michigan during 2018, finding 28 that use chemicals containing PFAS.
“Air Quality Division’s focus during permit review is on substances emitted,” he said. “However, we are trying to remain cognizant of how PFAS may persist or transform in the environment.”
One investigation in southeast Michigan prompted more consideration of that: The discovery of high levels of PFOS traveling from a Tribar plant into the Wixom wastewater treatment plant. As DEQ employees tested the site, they learned that PFAS also was moving into the city’s stormwater drainage – with the route likely through the factory’s air system to the rooftop venting.
Laboratory tests from the roof of the Tribar Plant 4 showed 8,000 parts per trillion (ppt) of PFOS, a level that’s more than 600 times the amount that would prompt a surface-water cleanup. The same test showed 2,900-ppt of FTS 6:2 alongside the PFOS, with both – along with less amounts of 14 other types of PFAS – washed off the roof in rainwater.
David Andrews, senior scientist for the Environmental Working Group, said the FTS 6:2 detection is not surprising.
“It’s one of the more common replacement chemicals,” Andrews said.
But he joins DeWitt in noting that the research on it trails the amount done on PFOA and PFOS, leaving a number of questions as awareness increases.
“As we understand more about the national contamination in regards to PFOA and PFOS and the entire class of chemicals, we’ll see much more come out (on FTS 6:2),” Andrews said.
The questions arise as industry still uses it. It’s commonly used as a PFOS replacement in Europe, for example, and among the frequently used chemicals by electroplaters in the U.S. Processes in plating call for mist suppressants to protect workers from fumes, and PFOS once filled that function. Today, as the industry searches for PFAS-free alternatives, it also is taking a closer look at FTS 6:2.
“Based on available data, the health and safety profile for the 6:2 FTS is significantly improved over PFOS. Importantly, 6:2 FTS is not persistent and is not bioaccumulative,” said Christian Richter, spokesperson for the National Association for Surface Finishers.
However, the trade group – which also includes chemical suppliers – also is actively analyzing the available data on the replacement chemical, which the EPA approves as a mist suppressant.
“The association’s initiative to evaluate the FTS alternative aims to determine, among other things, whether there may be even tiny traces of PFOS in the PFOS-free mist suppressants.”
So far, Richter said, one challenge is the lack of a commercially available and effective nonfluorinated product.
The new look by Michigan at FTS 6:2 is more targeted than that of either industry or the public health community.
The scrutiny it will get as a chemical under review may put it among an estimated 1,200 other chemicals with an existing screening level for air quality permits. Among them are three types of PFAS: PFBE, set in 1993, and PFOS and PFOA, set in 2018.
Even if FTS 6:2 joins them, there still isn’t a way to identify the amount emitted, Dolehanty said. Instead, the screening level would be set by a formula based on toxicology data and quantity of the chemical.
“A lot of the science is still in the works,” she said.
Meanwhile, PFAS activists and the public health community are asking for regulators to consider PFAS a class of chemicals. In Michigan, a panel of state scientists urged that in December, and it’s a call to action at the federal level to prompt faster cleanups at military installations and to set health standards for the group of related chemicals instead of just one by one.
The state’s look at FTS 6:2 is a small step, but it also “highlights the scope of this problem and something that hasn’t been very well-defined: The complexity of this chemistry and how many PFAS chemicals are out there,” Andrews said.