Cowa Bungie writes:

I just want to know if it's o.k. to sell tools in the US if they
failed Underwriters or import or Food and Drug or Whatever tests.

Unclear whether UL listing covers locking power switches. More to do with
electrical hazards.

The switch may have been defective, even if one ought to know about the
hair hazard. So the manufacturer may have some liability. The tort system
is supposed to determine that, flawed as it may be.