This report, “Comprehensive review of several surfactants in marine environments : fate and ecotoxicity”, is a compilation and summary of marine (water and sediment) data on exposure and effects for five surfactant classes of compounds AE, AES, AS, DTDMAC and LAS, commissioned by ERASM. Data from the literature and industry sources for 47 biodegradation and 307 eco- toxicological studies are reported and summarised. The quality of data provided in the publications was checked, those that were reliable and robust were included in this report.
EU legislation, namely the REACH regulation (Registration, Evaluation, Authorisation and Restriction of Chemicals - Regulation (EC) No 1907/2006), requires the inclusion of a ecotoxicological risk assessment for the marine environment for those chemicals that require a Chemical Safety Assessment [CSA]. This risk assessment can be based either on an extrapolation of freshwater data, or on data specific for marine species, where available. Marine data could also be used in a weight-of-evidence approach. Moreover, marine ecotoxicity data are considered a suitable substituent for missing freshwater data for chemicals in the EU CLP Regulation dealing with Classification & Labelling of chemicals and mixtures (ref. Regulation (EC) No 1272/2008), or in REACH PBT assessments.
Among the most important anionic surfactants (by production volume) are the linear alkylbenzene sulphonates (LAS), alcohol ethoxysulphates (AES), and alkyl sulphates (AS). The most important nonionic surfactants (by volume) are the alcohol ethoxylates (AE). Ditallow dimethylammonium chloride (DTDMAC), a quaternary ammonium compound is a historically commonly used cationic surfactant. Given their importance, these five surfactant groups are the focus of the present review.
However, aquatic environmental studies have mostly focused on the freshwater environment, and marine studies are considerably underrepresented by comparison. Existing data on the fate and ecotoxicity of surfactants in marine ecosystems have been summarised and current gaps within the literature are presented, thereby highlighting research areas where additional marine studies should focus.
Marine biodegradation studies for AE and LAS reported half lives in the range of 2 -30 days and 0.3 to 45 days respectively. Data suggest that these half-lives may be longer than quoted for freshwater. No marine biodegradation studies were found for DTDMAC. Only four biodegradation studies for AES and AS were found.
A wide variation in the number of published marine ecotoxicological testing studies was found for each of the surfactant classes. AS and LAS have been studied most, and AES and DTDMAC the least. Marine invertebrates are the most studied class of organism in acute toxicological assessments. Plants and fish are the least studied, particularly chronic studies. Where it was possible to compare eco-toxicology values, marine data ranges generally fell within typical freshwater data ranges.
|LC50/EC50||0.2 - 50||0.5 - 40||0.4 - 160||0.5 - 100||0.2 - 36|
Tab. 1: Typical ranges for acute marine ecotoxicity values
Significant gaps in data were found in the marine ecotoxicology assessments for all surfactant classes. To enable a robust and reliable risk assessment of effects of the surfactants on the marine environment, the gaps in the data found in this report will need to be filled.