Trusted by campers for 40 years, TST stops odor and lubricates sensors without staining your septic tank. Contains no formaldehyde and is 100% biodegradable. Available: 32-oz. liquid – 4 oz. treats 40 gal.21-oz. granular – 1 oz. treats 40 gal.32-oz. Orange Liquid – 2 oz. treats 40 gal. Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Type: Treatment Chemical.