GAO-25-107796 Substitution of Hazardous Chemicals
Science, Technology Assessment,
and Analytics
SCIENCE & TECH SPOTLIGHT:
SUBSTITUTION OF
HAZARDOUS CHEMICALS
GAO-25-107796, November 2024
WHY THIS MATTERS
Chemicals improve our lives through use in products and
services, and the number of chemicals in use continues to
grow. Sometimes a chemical is determined to be hazardous
to people or the environment, yet replacing it with another
chemical may introduce new hazards. Understanding the
risks and tradeoffs associated with chemical substitution
could benefit industry, regulators, and consumers.
KEY TAKEAWAYS
» It can take years to fully understand whether a chemical
is hazardous to people or the environment.
» Removing hazardous chemicals quickly from the market
can lead to replacement with substitutes whose safety
risks are largely unknown.
» Developing best practices and using approaches such as
artificial intelligence and manufacturing less- or non-toxic
chemical substitutes using green chemistry could help
reduce future chemical substitution risks.
THE SCIENCE
What is it? When a chemical used in industrial processes or
consumer products raises concerns due to known or suspected
harmful effects on humans or the environment, regulators or the
market may push for replacing it with a substitute chemical. The
U.S. Environmental Protection Agency (EPA) reports there are
over 42,000 chemicals currently manufactured, processed, or
imported in the U.S., as of May 2024.
What are the risks? Because a hazardous chemical may be
quickly removed from the market, a substitute could be used
that is not well understood and potentially may be found to be
equally or more harmful to human health or the environment.
For example, bisphenol A (BPA)—used in plastics and other
products—raised safety concerns when laboratory testing
indicated potential harmful effects related to reproductive
systems, obesity, and cancer. Despite decades of study, there is
still no consensus about whether BPA exposure is safe at the
levels at which people are exposed, and it continues to be used
in some products. While some companies have replaced BPA,
there are increasing concerns about the health risks of
substitutes that are chemically similar to BPA. Thus, consumers
may not fully understand safety risks when buying some
products labeled “BPA-free.”
Figure 1. Timeline of Health Risk Research Conducted on BPA
Another example involves chlorofluorocarbons (CFC), which
were used as refrigerants and in aerosols. When researchers
found that CFCs were damaging the earth’s ozone layer,
regulators acted to ban them. However, some of the substitutes
have since been identified as potent greenhouse gases, which
