Animals will remain experimental

In 2019, the regulator pledged to completely phase out animal toxicology tests by 2035 in favor of programmed computer models. This would impact thousands of studies and experiments, but many scientists argued from the beginning that computer models were not yet ready to replace animals due to their flaws.

In a letter written by a group of health officials, experts urged EPA Administrator Michael Regan to reconsider the ban because: Computer models are “not yet advanced enough” to be trusted in risk assessment, they say.

The EPA said “scientific certainty” that virtual models can reliably replace animals such as mice and rabbits in laboratories is needed for the new ban to take effect.

Although the 2035 deadline has been lifted, an EPA representative told Science: the agency will still study alternatives to animal testingSo the ambitious plan is not a completely lost cause. While the EPA hasn’t made any official statements about how the agency plans to work toward its primary goal, some studies show that: computer models can effectively represent the toxicity of at least some chemicals They perform better during tests, in some cases even better than laboratory mice.

3D advances such as engineered organoids are also entering the research arsenal, with stem cells allowing artificial livers to be tested and evaluated in research; they respond to the scientists’ actions the same way a real human liver does. Labs are currently working on how to create realistic organs more efficiently using 3D printers. But it may be some time before 3D printing is routinely used to aid research and drug testing.