“Environmentally friendly” flame retardants break down into potentially toxic chemicals
A
purported "eco-friendly" flame retardant breaks down into smaller,
possibly harmful chemicals when exposed to heat and ultraviolet light,
according to a study from German researchers.
The
study, published in Environmental Science and Technology, is the first to
show that a popular insulation flame retardant degrades into dozens of smaller
chemicals and casts doubt that the "green" flame retardant is as
harmless as touted.
It's
also the latest example of manufacturers discontinuing harmful chemicals only
to produce replacement chemicals with similar structures and exposure concerns.
"This class of flame retardant is rapidly becoming the most-used type of flame retardant in the world," Joe Charbonnet, science and policy associate at the Green Science Policy Institute, told EHN.
"And they break down into things that look just like old flame retardants," said Charbonnet, who was not involved in the new study.
The
flame retardant chemical—mostly used in insulation products and marketed as
Polymeric FR (or PolyFR)—was touted as "breakthrough sustainable
chemistry" when released by manufacturer Dow Chemical Company in 2011.
In
a press release the company called it the "next generation industry
standard" for flame retardants. About 26,000 pounds of the chemical are
made each year.
Dow
made these claims because, unlike previous flame retardants, Polymeric FR has
larger molecules, which makes it less likely to get into wildlife and people
and build up in their bodies, as former flame retardants were doing.
However,
researchers from Germany report today that when the flame retardant is exposed
to ultraviolet light it breaks down into 75 different compounds, and many of
these breakdown products contain bromine. When they exposed the compound to
high heat—about 140 degrees Fahrenheit—there were seven breakdown compounds
formed, one of which contained bromine.
Breakdown
compounds with bromine are quite similar in structure to the brominated flame
retardants being phased out, such as PBDEs, that build up in the environment,
wildlife and people and are linked to disturbing health impacts: altered brain
development, hormone disruption, diabetes, negative effects on the liver,
thyroid and nervous, immune and reproductive systems.
While
the researchers didn't test whether or not the breakdown products were toxic to
people, the similar structures are a red flag.
The
smaller brominated compounds "might be harmful to humans, especially when
exposed to a mixture of these degradation products over a long period of
time," said Christoph Koch, lead author of the study and a researcher at
the University of Duisburg-Essen, in a statement.
"We
have to make smart inferences," Charbonnet said. "The [breakdown
compounds] look like other things that we know are toxic."
Regrettable
substitutions
The
authors point out Polymeric FR is mostly installed behind roofs and walls so
probably wouldn't face much UV radiation, however, "the whole life cycle
of a product should be considered," they write.
There
could be UV, or heat-induced, breakdown of the insulation both prior to or
during installation (think a hot attic) or after it is sent to a landfill.
And,
given the high use of the compound, even small amounts of degradation could
have big impacts.
"Even a loss of 1 percent of PolyFR's mass can lead to significant amounts of degradation products over several years," Koch said. "Given that [more than] 26,000 tons of PolyFR are produced each year, our research suggests that the environmental impact of this flame retardant is larger than anyone suspected."
Charbonnet
said it's time to take "concrete steps to avoid whole classes of
compounds."
"When
one flame retardant chemical is revealed to be toxic, manufacturers replace it
with a chemical cousin that turns out to be toxic, it's a phenomenon called
regrettable substitutions," he said. "We need to stop calling these
"greener"— at the very least, the jury is still out, more and, more
likely, they don't have better health and environment outcomes."
We've
reached out to Dow Chemical and will update the story when they respond.
