Prior to the widespread adoption of LAS as a surfactant ABS - Branched Alkylbenzene Sulfonate, was commonly used in detergents. ABS has served consumers well but foam-related environmental problems began to appear in surface waters, groundwater, drinking water and in wastewater treatment plants. These problems were caused by the inability of ABS to biodegrade. ABS is therefore classified as a non-biodegradable or a "hard detergent”.
Over the last 25 years ABS has been gradually replaced by LAS and that has brought great relief to the environment. Additionally LAS possesses many Processing and Performance Advantages over ABS, making it the preferred surfactant nowadays.

The following studies from around the world have shown and proven LAS’s positive impact on the environment. (those studies are published with kind permission from CLER).

..oO( UNITED STATES )Oo..

Surfactant concentrations in river waters dramatically decreased. The Illinois River at Peoria, Illinois, is highly polluted because of sewage and industrial plant effluents and storm water runoff from the greater Chicago area. From 1959 to 1965, the average MBAS - Methylene Blue Active Substance concentration in the river was 0.54 ppm. In the year following the conversion to LAS, the average MBAS value dropped to 0.22 ppm. By the spring of 1968, it had dropped even lower, averaging 0.05 ppm. In addition, analytical work showed that only 20 percent of the MBAS present was actually LAS.

A recent U.S. monitoring study of 50 river sites directly below wastewater treatment plants showed that the average LAS concentration was 0.035 ppm. Furthermore, 90% of over 500,000 U.S. river miles in the U.S. have less than .00 4 ppm LAS.
 
..oO( ENGLAND )Oo..

When ABS was replaced with LAS in England, the surfactant concentration in river waters dropped by a factor of five. By 1966, surfactant levels had reached the lower limits of analytical detection. Today they are almost certainly lower. These changes occurred even though the volume of detergents used, and therefore the amount entering the environment, had greatly increased.
 
..oO( GERMANY )Oo..

From 1958 to 1964, MBAS residues in surface waters of the Rhine River basin increased constantly, paralleling the rapid increase in ABS consumption. The conversion to LAS in 1964 resulted in the immediate reduction of MBAS levels. Average MBAS concentrations continued to drop until pre-1958 levels were observed by the late 1970's. This overall reduction occurred despite a population increase of approximately 6 million people and a two-fold increase in detergent consumption over 1958 levels. From 1978 to 1987 the MBAS levels dropped to below 0.05 ppm. LAS specific analyses suggest that only about 0.01 ppm LAS is currently present in the Rhine River.
 
..oO( JAPAN )Oo..

Similar results were observed in Japan. One example is that of the Tama River. which passes through heavily populated areas and receives large quantities of untreated domestic sewage. Even though the levels of organ ic pollutants in the river had reached the 8-10 ppm BOD level by the early 1980's, the yearly average MBAS residues had steadily decreased from a high of about 2.5 ppm in 1968 to 0.3 ppm in 1981 as a result of the use of LAS.
 
..oO( THAILAND )Oo..

In July-August 1983, the average MBAS residual over the 10-48 kilometer zone of the Chao Phraya River was 0.34 ppm. After switching to LAS, the average value over the same zone had decreased by 72 percent to 0.09 5 ppm by July of 1984.
Thus while there is extensive evidence that ABS causes environmental problems, there is now also overwhelming evidence that these problems are solved by changing to the use of LAS. This remains true regardless of geographical location, climate or environmental conditions.