Testing new creams on bits of human foreskin to spare lab rats, or whipping seaweed and spicy Sichuan pepper into potions - greener, cleaner cosmetics are on the march.

"If you develop a product that's pleasant, efficient and safe, but that wastes energy and water, you're not doing your job," Gerard Redziniak, head of the 1,600-member French Society of Cosmetology, said at a two-day international congress on cosmetics research in the French city of Orleans.

However, Redziniak added that despite scientific advances in the field, the aim of the game broadly remained unchanged.