How does boric acid kill cockroaches?

I’ve heard that boric acid powder for roaches is quite effective. How does it actually work?

Boric acid works as a slow-acting poison when cockroaches come into contact with it and ingest it while cleaning themselves. The fine boric acid powder sticks to their bodies as they crawl through treated areas. When they groom themselves, they swallow the powder, which interferes with their nervous systems.

Boric acid dust or powder can be useful as part of a wider cockroach treatment plan, but it’s generally not a standalone fix. The roach powder must be applied correctly in a very fine layer, as roaches can avoid treated areas if the powder is used too heavily. It also doesn’t kill eggs, and can miss young cockroaches hidden in inaccessible areas. So relying on boric acid as a roach killer alone is unlikely to address the root cause.

Extra care must be taken if pets or children are present. Always read the manufacturer's instructions carefully before using boric acid powder. 

If you’re trying to get rid of roaches with boric acid, it’s important to note that it’s most effective when professionally applied as part of a wider pest management plan that includes sealing entry points, removing attractants like food sources, and using professional cockroach treatment where needed.