(also linear alkyl benzene sulfonates or LAS, linear alkyl sodium sulfonates) A class of synthetic surfactants (see Surfactants below for more information). ABS are very slow to biodegrade and seldom used. LAS, however, are the most common surfactants in use. During the manufacturing process, carcinogens and reproductive toxins such as benzene are released into the environment. While LAS do biodegrade, they do so slowly and are of low to moderate toxicity. LAS are synthetic. The pure compounds may cause skin irritation on prolonged contact, just like soap. Allergic reactions are rare. Because oleo-based alternatives are available, LAS should not be used. Found in: Conventional laundry detergents (usually identified as "anionic surfactants").