The Great Chemical Unknown: A Graphical View of Limited Lab Testing

Only a tiny fraction of the compounds around us have been tested for safety

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Experts guesstimate that about 50,000 chemicals are used in U.S. consumer products and industrial processes. Why the uncertainty? The 1976 Toxic Substances Control Act does not require chemicals to be registered or proven safe before use. Because the Environmental Protection Agency must show, after the fact, that a substance is dangerous, it has managed to require testing of only about 300 substances that have been in circulation for decades. It has restricted applications of five.

The House Toxic Chemicals Safety Act of 2010 and the Senate Safe Chemicals Act of 2010 would require manufacturers to prove that existing and new chemicals meet specific safety criteria. Stricter scrutiny in Europe and Canada suggests that “10 to 30 percent of U.S. chemicals would need some additional level of control,” says Richard Denison, a molecular biochemist at the Environmental Defense Fund. That would be 5,000 to 15,000 chemicals, not five.

Mark Fischetti was a senior editor at Scientific American for nearly 20 years and covered sustainability issues, including climate, environment, energy, and more. He assigned and edited feature articles and news by journalists and scientists and also wrote in those formats. He was founding managing editor of two spin-off magazines: Scientific American Mind and Scientific American Earth 3.0. His 2001 article “Drowning New Orleans” predicted the widespread disaster that a storm like Hurricane Katrina would impose on the city. Fischetti has written as a freelancer for the New York Times, Sports Illustrated, Smithsonian and many other outlets. He co-authored the book Weaving the Web with Tim Berners-Lee, inventor of the World Wide Web, which tells the real story of how the Web was created. He also co-authored The New Killer Diseases with microbiologist Elinor Levy. Fischetti has a physics degree and has twice served as Attaway Fellow in Civic Culture at Centenary College of Louisiana, which awarded him an honorary doctorate. In 2021 he received the American Geophysical Union’s Robert C. Cowen Award for Sustained Achievement in Science Journalism. He has appeared on NBC’s Meet the Press, CNN, the History Channel, NPR News and many radio stations.

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Scientific American Magazine Vol 303 Issue 5This article was published with the title “The Great Chemical Unknown: A Graphical View of Limited Lab Testing” in Scientific American Magazine Vol. 303 No. 5 ()
doi:10.1038/scientificamerican112010-5fsMxUP9f9YoM7ofbpLpYm

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