If by pyro you mean pyrogallol then both the powder and solutions are very dangerous. In solution it is rapidly absorbed thru the skin. The LDlo (smallest lethal dose) is 26 mg per kg of body weight. Even in small amounts repeated skin contact should be avoided. Contact with dichromate solutions can cause skin irritation. Ingestion can be fatal in very small amounts. When dealing with the powders wear a respirator and nitrile gloves. With solutions gloves are still required. If possible I would recommend avoiding either chemical.