I find this surprising, are you sure it's not based on the concentration of the permethrin? Here in the US, I was able to buy a clothing spray of 0.5% permethrin from Home Depot. I'm also reasonably certain that at least some lice shampoos I've seen at my nearby CVS use permethrin, although I checked the one I bought and it doesn't have it.
Can confirm above comment. Only thing close we can buy is permethrin impregnated clothes for mosquitoes. No permethrin anything otherwise. I have some, but only because I had my sister ship it from the states. Blows my mind that you can buy up to 36% permethrin by the jug down there