Register for an account


Enter your name and email address below.

Your email address is used to log in and will not be shared or sold. Read our privacy policy.


Website access code

Enter your access code into the form field below.

If you are a Zinio, Nook, Kindle, Apple, or Google Play subscriber, you can enter your website access code to gain subscriber access. Your website access code is located in the upper right corner of the Table of Contents page of your digital edition.


The Toxinator: EPA Robot Tests Chemicals to See if They're Poison

The EPA and independent researchers can't possibly test the huge range of chemicals found in products we use. But now a tireless, efficient bot will take on the task.

By Valerie RossAugust 26, 2011 5:00 AM
Image courtesy Howie Choset/Carnegie Mellon University | NULL


Sign up for our email newsletter for the latest science news

More than 83,000 chemicals go into solvents, cosmetics, and other American products, but no one knows how the vast majority of them affect our health. For the Environmental Protection Agency, screening a single chemical can take years and cost millions. The agency has ordered testing on just 200 compounds and restricted or banned only five since it gained the authority to regulate new chemicals in 1976 under the Toxic Substances Control Act. (Among the banned substances are polychlorinated biphenyls, or PCBs, which can cause cancer and liver dysfunction.)

Now, after 35 years of criticism for lax oversight, the EPA is adopting a new technology that promises to put some teeth into the 1976 law. In March the agency introduced a $4 million, six-ton screening robot called Tox21 that is on track to test 10,000 chemicals over the next two years for just a few hundred dollars each, says EPA biologist Bob Kavlock. To pick out potentially harmful substances, the robot first loads samples of 1,400 chemicals at 15 different concentrations onto a set of plates. Then it plunks the plates into a device that adds cells modified to glow if a chemical interacts with them. After a 24-hour incubation, the robot identifies which combinations are aglow so that researchers can perform further testing.

The EPA has even launched a website to share results from Tox21 and other screening tests. Bisphenol A, an ingredient in plastics that mimics estrogen and has been linked to breast and prostate cancer in mice, is among the first batch slated for screening. Says Kavlock, “There’s tremendous payoff every direction you look.”

3 Free Articles Left

Want it all? Get unlimited access when you subscribe.


Already a subscriber? Register or Log In

Want unlimited access?

Subscribe today and save 70%


Already a subscriber? Register or Log In