(Link) The easiest way to remember this is that it means milligrams per kilogram. If you have 100 milligrams of Vitamin E in a lotion and you have one kilogram or 1000 grams of lotion, you would have 100 ppm Vitamin E in that lotion.
The home of SwiftCraftyMonkey Formulating Inc.! Join Susan as she obsesses about cosmetic chemistry and other things (some possibly related to monkeys). Often strange, occasionally useful, and always worth a stop as a point of interest on your journey through the Intertron.
