Think the federal government grinds too slowly on reviews and decisions? Tox21 is out to change your mind.
Tox21 is a high-speed robot screening system that several federal agencies will use to test 10,000 chemicals for potential toxicity. The system marks the beginning of a new phase of an ongoing collaboration (also called Tox21) that is working to protect public health by improving how chemicals are tested in the United States.
The Tox21 system can “test in a day what would take one year for a person to do by hand,” said Christopher Austin, M.D., director of the National Chemical Genomics Center at the National Institutes of Health, where the system is housed. “The Tox21 collaboration will transform our understanding of toxicology…”
The Tox21 collaboration also includes the Environmental Protection Agency, the National Institute of Environmental Health Sciences’ National Toxicology Program, and the Food and Drug Administration.
Tox21 is designed to merge existing research, funding and testing tools to develop ways to predict more effectively how chemicals will affect human health and the environment.
The robot system will screen 10,000 chemicals used in industrial and consumer products, including paint and coatings, food additives and drugs. Testing results will provide a basis for evaluating if these chemicals have the potential to disrupt human body processes enough to lead to adverse health effects, federal officials say.
|Tox21 can perform a now-yearlong toxicity screening process in one day, the government says.|
“Tox21 has used robots to screen chemicals since 2008, but this new robot system is dedicated to screening a much larger compound library,” said NHGRI director Eric Green, M.D., Ph.D.
‘Industrial’ Chemicals Targeted
The first phase of the project tested about 300 chemicals. The second, or “industrial,” phase will test 10,000 chemicals and compare those data to current toxicity information to test the robot’s accuracy.
About 80,000 chemicals are now being used in U.S. food and consumer products, but the government knows little about their health and environmental risks.
“The testing of environmental chemical for toxicology was expensive, inefficient, not terribly predictive of toxicity, and slow,” Austin told greenwire.com. “Because of those things, the vast majority of chemicals in the environment have no data.”
‘Smarter, Better, Faster’
The new system “will allow the National Toxicology Program to advance its mission of testing chemicals smarter, better and faster,” said Linda Birnbaum, Ph.D., NIEHS and NTP director.
“We will be able to more quickly provide information about potentially dangerous substances to health and regulatory decision makers and others, so they can make informed decisions to protect public health.”
Tox21 has already screened more than 2,500 chemicals for potential toxicity using robots and other innovative chemical screening technologies. The Tox21 technologies were used to screen the different types of dispersants for potential endocrine activity during the BP oil spill in the Gulf of Mexico last year.
EPA contributes to Tox21 through the ToxCast program and by providing chemicals and additional fast, automated tests. ToxCast currently includes 500 chemical screening tests that are assessing more than 1,000 chemicals.
While EPA must test one chemical at a time and can complete only a couple dozen assessments a year, Tox21 is capable of screening thousands of chemicals multiple times in a week, its creators say.
How it Works
The Tox21 testing system resembles methods long used by pharmaceutical companies in drug development, reports greenwire.com.
A chemical is placed on a 3-by-5-inch plate with more than 1,500 wells, each holding different human or rodent cells. One well might contain liver cells; another, brain cells; and so on.
The robot puts the tray under a pin tool, which has a corresponding pin that lines up above every well. The pin tool lowers and dispenses the chemical being tested simultaneously into each well. The robot’s arm then puts the tray in an imager, which scans for biological activity. Scientists can see how chemicals and cells interact, with toxicity sometimes indicated by fluorescence, explains greenwire.
EPA’s National Center for Computational Toxicology is developing algorithms to refine and better interpret those indicators.
Says Austin: “It is going to completely revolutionize the way chemical testing is done.”