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Environmental Protection Agency (EPA)

Environmental Protection Agency (EPA)

The U.S. Environmental Protection Agency (EPA) is tasked with protecting human health and the environment through research, monitoring, standard-setting and enforcement. Its Office of Chemical Safety and Pollution Prevention focuses on the risks posed by pesticides and toxic chemicals and relies primarily on the results of animal tests to establish “acceptable” exposure levels for these chemicals. While millions of animals have been killed in toxicity tests over the course of its history, EPA has banned only a handful of toxic chemicals using its authority under the Toxic Substances Control Act of 1976.

The Chemical Industry and Animal Testing

The chemical industry has long benefited from EPA’s reliance on animal testing because the results of these tests are always subject to interpretation. On one hand, if a chemical is shown to cause harmful effects in animal tests, industry representatives claim that the results are not applicable to humans. A perfect example is the herbicide atrazine, which has been repeatedly shown to cause negative health effects in tests on animals. Yet it remains on the market and in extremely widespread use due to company claims that the effects seen in animals do not extend to humans, although mounting evidence is now suggesting otherwise.

At the same time, however, company officials stand by the results of EPA-required animal studies that show that their products are safe for humans. This is what happened with cigarettes for more than 20 years as industry scientists claimed that tobacco was safe for humans because animals who were forced to inhale cigarette smoke in laboratory experiments did not develop cancer. The inability of animal tests to reliably predict what happens in humans can lead to products being exempt from regulation for years while they are tested and retested on animals.

Even in cases where the government used animal studies to regulate products for human use, there have been problems. In the late 1970s, huge doses of saccharin were shown to cause bladder cancer in rats, and products containing saccharin were required to be labeled with a cancer warning. Subsequent “mechanistic” studies (studies that examine how a substance actually works in the body) showed that the cancer results applied only to rats and, supported by human epidemiology studies that found no consistent link between saccharin and bladder cancer, the substance was removed from the government’s list of possible human carcinogens in 2000.

New Science-based Approach Will Reduce Animal Use and Better Protect Humans

Now, after decades of animal testing, government scientists have been forced to admit that the results aren’t relevant to humans. In fact, EPA has taken steps to adopt the approach outlined in the landmark 2007 National Academy of Sciences report Toxicity Testing in the 21st Century: A Vision and a Strategy, which presents a strategy for moving away from animal testing toward cell-based and molecular approaches and the use of computational sciences. These new non-animal methods allow thousands of chemicals and mixtures to be tested in a short period of time—which is not possible to do using animals.

EPA’s Office of Pesticide Programs (OPP) recently developed a Strategic Vision for Adopting 21st Century Science Methodologies that lays out the path and set of tools it will use to reduce its reliance on animal tests and make better informed decisions regarding the hazards and risks of pesticide exposure. Significant progress has already been made. EPA’s ToxCast™ program applies high-throughput nonanimal screening methods and computational toxicology approaches to rank and prioritize chemicals for further study. It has the potential to reduce the number of animals used, explore a wider range of potential adverse effects, be both faster and cost-effective, and produce results that are more human-relevant. ToxCast has already been used successfully to reduce animal testing under EPA’s Endocrine Disruptor Screening Program. Additionally, EPA is exploring the use of computer modeling to predict the toxicity of chemicals based on known relationships between chemical structure and biological activity and to determine safe human exposures based on chemical use patterns.

OPP is also involved in validating nonanimal methods that can be used as replacements for tests in which pesticides are applied to the eyes and skin of animals in an attempt to assess eye and skin hazards. In another effort aimed at reducing animal use, OPP has analyzed years of pesticide data and determined that one of its required toxicity tests – acute dermal toxicity – can be waived if certain criteria are met. Widespread requests for this waiver by industry could spare hundreds of animals from testing each year. EPA has developed guidance documents for waiving other animal tests based on chemical properties and other factors.

The passage of the Frank R. Lautenberg Chemical Safety for the 21st Century Act in May 2016 will also contribute to the modernization of EPA’s approach to evaluating chemical toxicity, which, despite continuing advancements, still relies largely on cruel, ineffective animal tests. This amendment to the outdated Toxic Substances Act requires that EPA develop, prioritize, and use non-animal testing methods before toxicity tests on animals are considered. EPA must publish a strategy by June 2018 describing how it intends to carry out this mandate to develop and use alternative testing methods.

Follow the links below to learn more about the EPA’s animal testing programs: