Dark Secrets - Beware of Hidden Talc In Capsules Unbelievably, almost all manufacturers use talcum powder, a suspect human carcinogen, in their high speed encapsulators to produce encapsulated products. Manufacturers reps say, "You can run most products the best by adding 1 to 2% talcum powder per capsule", and for almost all high speed capsule manufacturers, that is exactly what is done. Ask if your supplier if they use nontoxic ways to run products without talcum powder or other toxic agents.