Individual foil packets that contain powder. A Formaldehyde and Bronopal Free formula. Campground friendly and complies with California regulations. The quick-acting holding tank treatment eliminates odors while digesting waste and toilet paper to prevent clogging, all without any harsh chemicals. Proudly made in the USA, Thetford’s AquaBio is formulated and tested safe for all RV toilets, holding tanks and septic systems.