Bio-Gel. Clean up of portable toilet waste just became a lot easier. Reliance BIO-GEL waste gelation powder works quickly to convert liquid waste into a gel in minutes and it masks odors! Just two tablespoons of BIO-GEL placed in your portable toilet will convert 1 gallon of black water to gel in minutes. BIO-GEL is safe for all portable toilets. Each package contains 12 oz of gelation powder.