Municipality-approved chemicals: the line between treatment and poisoning
The phrase to listen for is 'municipality-approved chemicals'. Approved residential products in the UAE are mostly modern pyrethroids, insect growth regulators and gel baits: compounds with low mammalian toxicity at label rates, designed to break down within hours or days indoors. A legitimate technician can tell you the product name, show you the label in Arabic and English, and produce a safety data sheet if you ask.
The practical rule for households: no legitimate residential treatment in the UAE involves sealing a unit with tablets or powders and leaving. If anyone proposes that, or offers a mystery chemical decanted into an unlabelled bottle, decline the job and report it to your municipality. The saving on a cheap quote is trivial against the downside.