In the case of Larrimore v. American National Insurance
Co. (184 Okla. 614, 89 P.2d 340 (1939)), a guy placed a package of rat
poison on the counter at a coffeeshop. Larrimore turned on a coffee burner and
the rat poison exploded. Larrimore sued on the grounds that since it was
illegal to "lay out poisons" in a place where people were eating, the
guy was negligent.
However, the Oklahoma Supreme Court came to the conclusion
that the Statute was designed to protect people from being poisoned, not
to protect people from explosions. Therefore, similar to the holding in The
Polemis Case (3 K.B. 560 (1921)), the negligence wasn't
connected to the actual damage, so there isn't enough to sustain proximate
cause.
The idea that rat poison would explode is not foreseeable
and therefore outside the scope of duty.