This mosquito repellent is scent-free and non-toxic to humans. And thus, Thermacell was born. Inside all their products is an allethrin-saturated mat that is heated by a small fuel cartridge or lithium-ion battery.

Is Thermacell safe to breathe?

Safety precautions Thermacell is approved by EPA, but you need to use it away from uncovered food while operating it. It’s also important to avoid directly inhaling its vapor because of the allethrin that it contains. Allethrin is toxic to bees, cats, and fish, therefore, avoid exposing it to these creatures.

Does Thermacell cause cancer?

A few caveats about some potential risks. Amazon includes a Proposition 65 warning for California residents that discloses that Thermacell’s repellent contains chemicals known to cause cancer and birth defects. Allethrin and metofluthrin are also toxic to some animals including birds, fish, bees and cats.