We have to assume Costco has a pretty rigorous food safety program. And safe chicken, as we’ve been told ad infinitum, is chicken that’s cooked to 165 degrees Fahrenheit; at that point all the salmonella on it should be dead.

Well, guess what? Costco cooks its chicken to 180 degrees Fahrenheit, a margin of error that the company believes renders the chicken safe. But that didn’t work here. Which means, as far as I can tell, one of four things: the chicken wasn’t cooked to 180 degrees Fahrenheit; or there was some cross-contamination; or there was so much salmonella on the birds that even “proper” cooking couldn’t kill it all (this can happen; 165 degrees Fahrenheit isn’t a magic number); or … maybe there’s now a strain of salmonella that isn’t killed at 165 degrees Fahrenheit.

I asked Congresswoman Louise Slaughter, Democrat of New York, who has a degree in microbiology, whether that last was possible. Her answer was immediate and unequivocal: “Of course it is.” Daniel Englejohn, deputy assistant administrator at F.S.I.S., said that there is “no evidence that these strains are more resistant to heat than others.” When I asked if the agency might choose to err on the side of caution, he said, “We did take an action to alert the public to safely handle and prepare their products.” Wow.

To its credit, Costco pulled the rotisserie chicken from its shelves, as did a couple of other retailers. (To its debit, Costco left raw Foster Farms chicken on the shelves, once again transferring the burden of safety to the consumer, even though the store must have known that it couldn’t guarantee that cooking the chicken would render it safe.) Foster Farms has not recalled a single piece of chicken, although it’s arguable that this same contamination has been going on for months. And F.S.I.S. officially has no power to do so.

The agency could, however, remove its inspectors from the three suspect plants, which would close them, and last week it threatened to do just that. Three days later, Foster Farms “submitted and implemented immediate substantive changes to their slaughter and processing to allow for continued operations.” What’s that mean? “We cannot tell you what their interventions are, because that’s a proprietary issue,” said Englejohn, adding that the interventions comprise “additional sanitary measures that reduce contamination.” Well, we hope so.

Meanwhile, commerce continues and the chicken is out there. Will it be taken off the market after 800 people get sick? Or 1,200? Or when someone dies? Or, as F.S.I.S. would prefer, will this just die down until the next time?

We should not have to handle chicken as if it were a loaded gun, nor should we be blamed when contaminated chicken makes us sick.