Green queen Boric acid is fatal to roaches but in small amounts has low toxicity to humans.
Boric acid means bye-bye roaches
Earlier this year I developed a cockroach problem - one that seemed only to escalate after I hired a professional company to spray poisonous pesticides and leave gross globs of brown gunk all over the apartment. I resorted to going mental with a fly swatter and can of insecticide every time I spotted a bug. It was only after an extended such session earlier this month, which disturbingly left my lips numb for hours and throat and chest burning for days, that I vowed to find a more effective and less toxic solution.
Enter Mike Potter, a professor of entomology at the University of Kentucky's College of Agriculture, a boric acid enthusiast and my new hero. It turns out that boric acid is fatal to roaches but in small amounts has low toxicity to humans. So I ripped my kitchen apart and spent hours cleaning it, putting away any and all food packages that were not already in airtight containers. Then I bought a small container of the colourless, odourless powder for Dh7 at a local pharmacy.
Using an old makeup brush and following Potter's suggestions, I dusted the powder in a thin, barely perceptible layer along crevices, cracks, cupboards and anywhere else I'd seen the little critters. The dust will remain effective indefinitely, unless it gets wet. There is a reason that people have been using this stuff against cockroaches for centuries. I'm breathing easier, and the roaches disappeared almost immediately and have stayed away.