Ultimate Biodegradation of Commercial Linear Alkylbenzene Sulphonates (LAS) Under ISO 14593 Headspace CO₂ Test: Compliance with EU Detergent Regulation 648/2004

Abstract

The EU Detergent Regulation 648/2004 introduces a new pass-fail criterion for the biodegradability of all surfactant classes used in household detergents. The new criterion is based on the determination of the mineralisation of the surfactant, ultimate biodegradability. There are a series of official biodegradation tests allowed in the new Regulation as well as a reference test based on the ISO 14593 method. There are few data in the literature about the biodegradation results of common surfactants using the above methodology and consequently the aim of our study was to apply it to a variety of commercial LAS products. Both the influence of the counter-ion and initial concentration of LAS have been assessed. The results confirm that LAS complies with the ultimate biodegradation requirements fixed on the new EU Detergent Regulation.

Comment on “Degradation of Two Persistent Surfactants by UV‐Enhanced Ozonation”

“…This comment next examined the unreferenced statement of Tehrani-Dagha et al [1] that LAS is a ''persistent'' surfactant of ''low biodegradability.'' This statement is contradicted by published studies and reviews which report that LAS passes stringent laboratory tests designed to measure ready biodegradability [3,[5][6][7]. LAS demonstrates rapid and complete biodegradation (mineralization) that has been shown to be ''a practically significant removal mechanism in a broad range of aquatic, benthic and terrestrial habitats'' [4].…”

“…that LAS is a ''persistent'' surfactant of ''low biodegradability.'' Instead, LAS should properly be characterized as a readily biodegradable surfactant [3,[5][6][7] that demonstrates rapid and complete biodegradation (mineralization) as a practical method to significantly remove LAS from the aquatic environment [4].…”

“…The project is a European voluntary initiative conducted by A.I.S.E., representing the formulators and manufacturers of household cleaning products, and Cefic, representing the suppliers and manufacturers of the raw materials. 3 The assessment concluded that:…”

“…Because LAS is the only anionic surfactant discussed in the Tehrani-Bagha et al [1] paper, the implication is that this statement applies to LAS. In fact LAS passes stringent laboratory tests designed to measure ready biodegradability [3] and rapidly and completely biodegrades (mineralizes) in laboratory tests that model ''real world'' environmental conditions [4]. While LAS is a large volume surfactant-it is extensively used in laundry detergents and cleaning products worldwide [5]-environmental assessments have been conducted on LAS in North America, Europe and globally which have concluded that current LAS uses are not of concern and pose low risk to the environment [5][6][7][8][9].…”

“…The U.S. Environmental Protection Agency was the lead agency. An international consortium of LAS supplier and detergent companies worked with EPA in producing the assessment 3. Additional information on the HERA Project, A.I.S.E.…”