Chemical Safety Cover figure

by Cory Gerlach
figures by Tito Adhikary

There are currently more than 85,000 chemicals in the US that make up the products in our daily lives and few, besides medications and pesticides, have been assessed thoroughly for safety. In fact, the federal government has had relatively little oversight over most chemicals in commerce (Figure 1). As a result, nearly all of the chemicals in our cosmetics, clothing, furniture, electronics, cleaning products, gasoline, and construction materials have not been tested. This has led to certain chemicals like asbestos and lead remaining in the marketplace for decades before their detrimental effects on human health were recognized. Until recently, the United States has been like the Wild West with regards to chemical regulation.

Figure 1: Everything we see, hear, taste, smell or touch is made up of chemicals. Chemicals are found in cosmetics, clothing, furniture, electronics, cleaning products, gasoline and construction materials. Unfortunately, few of them have been tested for safety before entering commerce.
Figure 1: Everything we see, hear, taste, smell or touch is made up of chemicals. Chemicals are found in cosmetics, clothing, furniture, electronics, cleaning products, gasoline and construction materials. Unfortunately, few of them have been tested for safety before entering commerce.

The Frank R. Lautenberg Chemical Safety for the 21st Century Act intends to address many of these problems. The Environmental Protection Agency (EPA) will finally have the authority to require testing of every new chemical that enters the marketplace and can also ban chemicals if they are shown to pose risks to human health or the environment. This new law was passed overwhelmingly by Congress and was signed by President Obama in June 2016, after receiving enormous support from public health and environmental groups as well as the chemical industry. But now the question becomes: will the new law keep us safe?

What is chemical safety anyway?

In toxicology, the guiding principle is “the dose makes the poison.” This means that any chemical, including water, could be toxic if given in high enough amounts over a short enough time. Before prescription drugs can be safely given to people, for instance, pharmaceutical companies must first conduct thorough toxicity studies in the lab (Figure 2). In most cases, small animals (like mice and rats) are given the drug at increasing doses and assessed for short- and long-term side effects. These side effects may include changes in behavior, appetite, or serious responses such as cancer, organ failure, reproductive problems, or death. If a safe dose is determined in at least two animal species, drugs may then be given to a small group of human volunteers who are monitored for any negative reactions. Pesticides go through a similar level of scrutiny to determine concentrations that are safe to humans and the environment. However, what has separated drugs and pesticides from the chemicals in most other consumer products is that there has been little toxicity testing and few limitations on exposure from the latter. Other than some short-term tests like ensuring that a chemical does not cause a serious skin reaction, most chemicals are not assessed for long-term effects such as their ability to cause cancer or affect brain development.

Figure 2: Pharmaceuticals must undergo multiple levels of toxicity testing before they are approved for human use. This includes extensive preclinical testing in animals such as mice and rats before going through successive stages of human testing with increasing numbers of diverse patients. However, before the Frank R. Lautenberg Chemical Safety for the 21st Century Act passed early in 2016, chemicals in consumer products underwent little or no toxicity testing before being approved.
Figure 2: Pharmaceuticals must undergo multiple levels of toxicity testing before they are approved for human use. This includes extensive preclinical testing in animals such as mice and rats before going through successive stages of human testing with increasing numbers of diverse patients. However, before the Frank R. Lautenberg Chemical Safety for the 21st Century Act passed early in 2016, chemicals in consumer products underwent little or no toxicity testing before being approved.

Did any regulations exist before the new law passed?

Forty years ago, the Toxic Substances Control Act (TSCA) granted the EPA the responsibility to ensure the safety of chemicals in manufactured products. At first glance, it appeared that the law would work, but over time TSCA was largely viewed as a failure. First, TSCA exempted the 60,000-plus chemicals that were already in use before 1976 from any new testing. Second, though TSCA required all new chemicals to be approved by the EPA before reaching market, companies were only mandated to submit toxicity data that they had already generated. That meant that the EPA would have to judge chemicals based only on the limited information it was given. After passing this stage, or if the EPA did not make a ruling after 90 days, chemicals could then enter the marketplace without further oversight.

Since TSCA became law, the EPA has placed legal limits on the production of only a handful of chemicals, deemed The Toxic Five (Figure 3). This is largely because the burden of proof has been on the EPA to show that a chemical posed an “unreasonable risk” to public health or the environment. Moreover, the EPA was also required to choose the “least burdensome” regulation while considering both public health and the impact on the manufacturer. For example, the EPA previously attempted to use TSCA to institute a total ban on asbestos, which was ubiquitous in building materials and is still responsible for thousands of deaths in the US each year. However, the courts overturned the EPA’s complete ban in 1991 because they determined the agency did not choose the least burdensome regulation. Because of the difficulty regulating chemicals using TSCA, the EPA has mostly suggested a “voluntary phase-out” for other potentially harmful chemicals like flame retardants, which they admit are linked to learning disorders in children.

Figure 3: The so-called Toxic Five include cancer-causing compounds like asbestos, dioxin, polychlorinated biphenyl ethers and hexavalent chromium, as well as fully halogenated chlorofluorocarbons, which were responsible for the holes in the ozone layer. These are the handful of chemicals that have been regulated by the EPA using TSCA. However, TSCA was not strong enough to sustain a total asbestos ban.
Figure 3: The so-called Toxic Five include cancer-causing compounds like asbestos, dioxin, polychlorinated biphenyl ethers and hexavalent chromium, as well as fully halogenated chlorofluorocarbons, which were responsible for the holes in the ozone layer. These are the handful of chemicals that have been regulated by the EPA using TSCA. However, TSCA was not strong enough to sustain a total asbestos ban.

What does the new law actually do?

The Frank R. Lautenberg Chemical Safety for the 21st Century Act finally gives the EPA the authority to ban new and existing chemicals that pose a risk to human health and the health of the environment. To do this, the EPA must now make an affirmative determination on all new chemicals and all new uses of existing chemicals. Importantly, the EPA can now require more toxicity testing before chemicals are approved and, without considering economic impacts to the company, stop chemicals or limit their use based on the scientific evidence regarding human and environmental health. In addition, the EPA must develop a screening process for all existing chemicals that ranks them according to their level of risk. They will then develop a risk management strategy for chemicals that raise concerns.

The new overhaul also includes many provisions that will protect the greatest number of people while also ensuring innovations in science. For instance, all chemicals will be evaluated with considerations for vulnerable sub-populations (such as pregnant women and small children), in addition to possible chemical accumulation up the food chain. Furthermore, animal welfare will be increased due to new requirements to reduce, improve and ultimately replace vertebrate animal testing. New methods of assessing toxicity will be further developed such as computer programs that model how a chemical interacts within the body, biological markers that predict toxicity using human tissue, and building models using human cells from different organs that create the human body on a chip. To fund the law, companies will be required to pay fees to the EPA for evaluating data and regulating chemicals as well as for testing new chemicals should companies choose to outsource this responsibility. Lastly, nearly every aspect of the new law requires strict and enforceable deadlines for its implementation.

How did these new regulations pass Congress?

Back in 2011, Senator Frank Lautenberg (D-NJ) made it his mission to finally put some teeth into TSCA. He earned early bipartisan support from Senator David Vitter (R-LA), an ally of the chemical industry, and by 2013 had the backing of senators from both parties. However, there was one big snag: whether any future federal rulings would supersede state regulations. Over the last few decades, states like California and Massachusetts had tightened their chemical safety laws in the absence of strong federal oversight. The chemical industry, however, argued that disparate state laws made it too difficult to conduct business and that any new reforms should include uniform federal standards. Because of concern that the overhaul could threaten the autonomy of states to impose tighter regulations than the federal government, the chairwoman of the committee with jurisdiction over TSCA, Barbara Boxer (D-CA), temporarily halted the reform efforts. Shortly after, Senator Lautenberg passed away and TSCA reform was increasingly uncertain.

Senator Vitter then joined forces with Senator Tom Udall (D-NM) to keep the momentum moving forward. Eventually, Senator Boxer struck an agreement that ensured that the EPA could not supersede chemical laws enacted in states before 2016. Everyone agreed though that when the EPA makes a ruling on a specific chemical or its use, it would preclude states from issuing any new regulations on that matter. Chemical safety advocates such as the Environmental Defense Fund applauded the new authority that would be given to the EPA, and industry groups like the American Chemistry Council supported the establishment of uniform federal standards. In the end, the Frank R. Lautenberg Chemical Safety for the 21st Century Act passed with overwhelming support. Congress prioritized bipartisanship throughout this process and many are hopeful that both parties will continue to support its implementation well into the future.

How will this new law be implemented?

Currently, the EPA is seeking public comment for some aspects of how the new reforms will be implemented, which was required by the law. Time will tell whether the new law has the regulatory bravado Senator Lautenberg once envisioned. Because of the legacy of TSCA and its previous vulnerabilities in court, there is some concern that aspects of the new law could be challenged in the future. Still, public health advocates and industry groups involved in drafting this law argue that it will strengthen chemical safety while also ensuring chemical innovation. An American Chemistry Council spokesperson told Science in the News, “the new law will give Americans greater confidence that chemicals in commerce are being used safely, decrease the number of inconsistent state-based chemical initiatives… while also promoting innovation and growth by American manufacturers.” At this moment, with all sides of the issue cheering the new reforms, it appears that a new renaissance for chemical safety is real and here to stay.

Cory Gerlach is a PhD Candidate studying toxicology and drug development at Harvard University. Cory is a teaching fellow for the course “Principles of Toxicology: Molecular and Translational Toxicology” at Harvard T.H. Chan School of Public Health. He earned his BS in toxicology from Oregon State University.

This article is part of our Special Edition: Dear Madam/Mister President.

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2 thoughts on “New Toxic Substances Control Act: An End to the Wild West for Chemical Safety?

  1. While many people advocate for more safety testing, it is surprisingly hard to develop in vitro or in vivo models that can reliably predict the effect of a chemical on human health. Giving a substance to a lab rat at massive doses may cause measurable symptoms or damage, but it’s extremely hard to extrapolate to the trace levels of exposure that most of us experience.

    Even for a widely-used substance such as BPA, for which there are literally thousands of papers addressing its potential biological activity, it is still hard to for biologists to agree on what a “safe” level of exposure should be.

    In addition, literally thousands of substances in plants act as natural pesticides, and it’s doubtful if most of our foods would pass the stringent safety tests that are increasingly demanded of synthetic chemicals.

    Over-regulation of new substances may paradoxically increase our risk by encouraging manufacturers to rely on older, accepted compounds, rather than confronting the expense and delay of new safety testing.

    There is abundant evidence that pharmaceutical chemicals can interact in the body, resulting in enhanced activity (toxicity) or reduced efficacy. It’s not clear if this phenomenon applies to the traces of chemicals we are exposed to in the environment, but if it does, it would be very hard to predict our response to the huge range of possible combinations.

    A major source of possible toxicity is the wide range of nutritional “supplements” that many people consume — most of which are exempt from safety testing, thanks to previous lobbying. Personally, I am much more concerned about excessive vitamins, minerals and herbs than traces of pesticides, for example.

    1. These are extremely important points. However, the old paradigm of safety testing gave all chemicals the benefit of the doubt. We seem to have a consensus that unregulated chemicals can pose a great risk to people. That is why we demand extensive toxicity testing for pharmaceuticals and pesticides. It seems very hypocritical to let other chemicals slide.

      The new law has definite limitations and chief among them is that we are a ways away from being able to test chemicals cheaply and effectively. However, this new law will force us to start developing these techniques sooner rather than later (or never). We have already started a bit with high-throughput screening using zebrafish and improving ways of recapitulating human responses using organs on a chip. We also have a lot of toxicity assays developed for pharmaceuticals and pesticides.

      Though it may be years before we have the right assays and biomarkers of toxicity to be able to confidently and cheaply determine whether a chemical is safe in its intended use, this new law will force us to start moving toward this goal. The Europeans have done something similar with REACH and we can work with them to innovate and share best practices.

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