A research study backed by the American Cleaning Institute contends that the European Union's methodology overestimates the environmental impact of alkyl sulphate surfactants. "These results indicate the very conservative nature of the EUSES model for these materials," said Kathleen Stanton, a co-author on the research and an ACI associate vice president, adding: "While predicted concentrations can be informative, these concentrations should be corroborated by other means, including measuring environmental concentrations."