ENVIRONMENTAL FATE AND EFFECTS OF DEEDMAC - A NEW RAPIDLY BIODEGRADABLE CATIONIC SURFACTANT FOR USE IN FABRIC SOFTENERS

This paper introduces the environmental safety database for a new fabric softening cationic surfactant. the di-(tallow fatty acid) ester of di-2-hydroxyethyl dimethyl ammonium chloride, DEEDMAC (Diethyl Ester Dimethyl Ammonium Chloride). The physiochemical properties of DEEDMAC are similar to those for ditallow dimethyl ammonium chloride (DTDMAC), the major cationic surfactant used in fabric softener formulations world-wide for over thirty years. Importantly, however, DEEDMAC differs structurally from DTDMAC by the inclusion of two weak ester linkages between the ethyl and tallow chains. These ester linkages allow DEEDMAC to be rapidly and completely biodegraded in standard laboratory screening tests and a range of environmental compartments. including raw sewage, activated sludge, anaerobic digestor sludge, sludge amended soil. and river waters. Removal of DEEDMAC during sewage treatment is greater than 99%, as determined by computer model predictions and confirmed by laboratory simulation testing (OECD Continuous Activated Sludge confirmatory test). Using estimated tonnages, per capita waste water flows, incidences of sewage treatment for individual countries, measured removal rates, and validated computer models, maximum river water and soil concentrations of DEEDMAC have been estimated for representative usage scenarios. Based upon these maximum predicted environmental concentrations, acute and chronic toxicity testing of fish. invertebrates and algae, predicted aquatic safety factors range from 272 to >1000. Predicted steady state terrestrial safety factors are >1000, based on EC(50) values to earthworms and plants >50 mg/kg. The environmental safety database developed for DEEDMAC indicates that this cationic surfactant is rapidly and completely biodegraded will be highly removed during sewage treatment. has an ecotoxicity profile similar to broadly used anionic and nonionic surfactants. and is environmentally safe at intended maximum usage volumes.