They don't _want_ to do anything but maximize profits - regulating the level of lead in those products directly impacts the bottom line, hence the need for regulation.

The free market is awesome, but it can't effectively price externalities, especially those which have diffuse origins or targets.

OK, but this thread began with someone saying: "If food makers (or the makers of school supplies in this case) didn't want to kill you, then why is there high levels of lead in the food, a substance which is known to be very toxic?"

It is making the assumption that they are doing it to kill you against which I spoke.