A less toxic active ingredient than sugar

Etofenprox is a relatively recent active ingredient in the field of insecticides for civilian use.
Although its structure is similar to the commonly used pyrethroids available on the market, it has certain chemical properties that differentiate it from these, earning it the label of a “pseudo-pyrethroid.”

In the mechanisms by which an insect develops resistance, one often involves detoxification (i.e., deactivation) of the toxic molecule within the target organism. In pyrethroids, this deactivation occurs through the action of an enzyme called esterase, which works on a specific part of the insecticide molecule.

In the case of Etofenprox, that part of the molecule is slightly different, so the esterase enzyme has no effect on Etofenprox. For this reason, insects that have developed resistance to pyrethroids are not resistant to Etofenprox.

This feature is very important in managing resistance and allows the use of Etofenprox even where conventional pyrethroids show reduced effectiveness. Additionally, this molecule has an exceptionally broad spectrum of activity.

Characteristics of Etofenprox-based products

Another crucial characteristic of Etofenprox is its extremely low toxicity to mammals, and in this case, its molecular structure plays a key role.

In many pyrethroid insecticides, a synergist (PBO) is added to prevent the detoxification of the insecticide molecule by the esterase enzyme. However, this is unnecessary in products containing Etofenprox. In Etofenprox-based products, PBO is only useful if a conventional pyrethroid, usually tetramethrin, is also present in the formulation, as the PBO benefits the pyrethroid.

Many pyrethroids contain halogen atoms (Chlorine, Fluorine, Bromine) or cyanide (CN) groups in their molecules, which greatly increase toxicity to mammals. Etofenprox, however, contains only CHO atoms (Carbon, Hydrogen, Oxygen).

As a result, Etofenprox has an incredibly favorable toxicological profile (see graph).

Many pyrethroids have irritating or allergenic properties for the respiratory system (inhalation) or for the skin (contact), whereas Etofenprox has the advantage of not exhibiting these negative effects.