In a market that has been designed to let people take part in voluntary transactions, we also design methods for making sure that the counterpart takes responsibility, and delivers the agreed amount quality of product.
If you purchase a car that won't turn on, you're in your good right to make a claim against the producer. Same for all the other things you mention. And people do.
You're making a point about negative externalities. Agreed that a factory shouldn't just be able to poison a river, because there's no tangible cost to piping your dirty water to one. Here it makes sense to make artificial interventions, in my opinion.
A way more interesting conversation would be where to regulate, how much, for how long, what impacts would it have in innovation, etc not that I want to be free to get sold broken goods.
> as if anyone would purchase their goods from purveyors known to disregard food safety
How would you know they disregard food safety if there's no regulation on what food safety means?
that regulation acts as a lower bound on what it takes to do business in the place. You also pay for companies not dumping toxic material on the streets, for appliances not catching fire, for not eating rotten food and million other things. All of those regulations of course "corrupt" the market for the good of a society so it's not just a race to the bottom. The idea of a free for all market is an utopia that doesn't exist ... thankfully.