What household products quickly poison humans?
Lots of them, but most would do so in such an immediately painful fashion that it would be hard to ingest enough to do the job. Children, however, for some reason have a talent for getting down a deadly dose of things like aspirin and household cleaners before they feel the pain, so keep them out of reach or locked up. For a real thrill, try mixing different household cleaners–one budding chemist thought he’d pour some bleach into the stool while the Vanish was still bubbling. It exploded and he got the Darwin award. Another mixed bleach and ammonia; I don’t know whether he lived or not, but that was the stuff they used for gas attacks in World War I.