No one likes animal testing. But no one has come up with a better way to make sure that new chemicals will be safe for humans without it.

Until now.

Animal activists are applauding a new program that could help save thousands of animals from chemical testing.

At present, animals are used to gauge the toxicity of new chemicals or new chemical combinations before they hit the market, but these tests are expensive and often inaccurate due to the innate difference between laboratory animals and humans.

A joint effort by the Environmental Protection Agency, the National Institutes of Health, and the Food and Drug Administration is behind a project dubbed Tox21, which uses human cells in petri dishes to gauge the toxicity of various chemicals and chemical combinations.

In a study published in Nature Communications, lead researchers released the results of the initial Tox21 project in which they tested 10,000 different types of chemical compounds including pesticides, industrial chemicals, food additives and drugs. Each chemical was tested in 15 different concentrations as they reacted with various components of the human cells.

Using these tests, the researchers generated more than 50 million data points that they used to create models that could predict whether or not a new chemical or chemical compound would be harmful to humans. The study showed that these models could accurately predict toxicity for both animals and humans, eliminating the need to test the products on animals.

Researchers aren't sure that Tox21 will be able to completely replace animal testing, but the program could be used to filter out unsafe chemicals and chemical combinations much earlier in the development phase, potentially saving the lives of tens of thousands of laboratory animals.

Could human cell studies replace animal testing?
The Tox21 project uses human cells in a petri dish to predict the toxicity of new chemicals.