Consumer testing liquid syndets. II. Biodegradable formulations

The results of experiments investigating the interrelated effects of biologically degradable nonionic and anionic synthetic detergents in a light duty liquid detergent are presented. The formulations studied explore the performance of various biodegradable nonionic candidates in the presence of a fatty based alkylolamide foam stabilizer and biologically 舠soft舡 alkyl aryl sulfonate at two levels of nonionic concentration. The nonionic detergents evaluated are all polyoxyalkylated, including products of natural and synthetic origin. Products based on unsaturated and secondary alcohols are included. Consumer and laboratory test data show that biologically degradable detergents cannot be directly substituted in formulations without first testing their effect on the formulation itself. The data also show that small differences in molecular weight or in saturation of the materials being used can be reflected materially by technical differences in the finished product. These differences are manifested by analytical determination, by consumer panel evaluation using a duplicated balanced incomplete block design, and by standard dishwashing evaluation. The consumer panel data relate to dermatological properties, general performance and suds stability. It is obvious that the big switch to biologically degradable surface active agents is not as smooth a changeover as had been hoped, this being especially true for smaller producers of chemical specialties who do not have extensive facilities for formulation testing. These data do, however, indicate that with a careful experimental approach and judicious experimentation that formulations having a performance superior to their nonbiodegradable counterparts can be prepared. It is also stressed that judiciously designed consumer panel evaluations can yield data that is just as precise and valid as can be obtained through some of the more sophisticated testing procedures that require investment in equipment and in training of test panels.