This week’s alternative fact of the week turns on the definition of “science.” To some, it’s systemized knowledge derived from observation, study and experimentation, while to others it might be defined as the point of view of a preferred special interest group. Which do you suppose the head of the U.S. Environmental Protection Agency had in mind when he invoked that word?

EPA Administrator Scott Pruitt used the s-word on Wednesday in announcing that his agency wasn’t going to ban chlorpyrifos, a widely used pesticide that can harm children’s brains, overruling the judgment of EPA staff. “By reversing the previous administration’s steps to ban one of the most widely used pesticides in the world, we are returning to using sound science in decision-making — rather than predetermined results,” the former Oklahoma attorney general was quoted as saying in the agency’s press release.

That’s a pretty interesting conclusion given that the EPA hasn’t developed any new scientific evidence since agency scientists recommended the ban last year. And it’s not like the chemical was ever considered benign. It’s been banned for most household uses since 2000. And while it’s true that the petition to ban chlorpyrifos was brought by environmental groups (and opposed by Dow Chemical, its maker, as well as the farmers who profit greatly from its use), it’s the judgment of the EPA’s expert and independent staff that ought to be trusted as “science.”

Not all studies are created equal, of course, and there’s been criticism of some of the data presented by the petitioners both within and outside the EPA. But that didn’t prevent the agency from seeing the forest for the trees and finding too much evidence of harm to be ignored. That includes proof that prenatal exposure can lower birth weight and reduce intelligence and memory, as well as contribute to attention disorders and delay motor development. That’s made the poison particularly dangerous for farm workers and families that live near fields that have been sprayed with it.

Nor are farm workers and neighbors the only people who might be put in harm’s way. Eating fruits and vegetables that have been treated with chlorpyrifos is considered dangerous, too. The EPA’s own assessment of the chemical last year found children exposed to levels 140 times what is considered safe and noted the pesticide could be detected at unsafe levels in schools, homes and communities in farm areas.

Groups like the Natural Resources Defense Council are expected to challenge Mr. Pruitt’s decision in the 9th Circuit, so it will eventually be up to the federal judiciary to decide whether Mr. Pruitt was acting on science or something else. If the courts don’t reverse him, Americans could be stuck with the consequences of the decision for years to come as the administrator’s action isn’t scheduled to be re-evaluated for another five years.

Meanwhile, it’s clear that the Trump administration’s view of science is somewhere along the lines of its view of facts generally — highly flexible. President Donald Trump’s denial of climate change has often been observed as the leading example of this antagonism toward knowledge and academia, but denying the harmfulness of chlorpyrifos will have more immediate consequences — profits for Dow and lifelong damage to children exposed to unsafe levels of the pesticide.

Is protecting public health what Mr. Trump meant when he said environmentalism is “out of control” in this country? Here’s a worthwhile scientific experiment: Perhaps the president’s and Mr. Pruitt’s claims would ring truer if they agreed to serve up chlorpyrifos to their own children and grandchildren (only at levels that studies have documented exist in other kids, of course) and then see whether their understanding of the difference between “science” and “special interest” has become more enlightened.