Toxicity of surfactants

Obviously this is not just another book in the series my involvement as co-editor of the book, together with my two old friends, Thomas Knepper and Pirn de Voogt, makes this book rather special to me. Everything started in 1996 when I first met separately with Thomas and afterwards with Pirn and we decided to establish a consortium covering the analysis, behaviour and toxicity of surfactants in the aquatic environment. 

TOXICITY OF SURFACTANTS FOR AQUATIC LIFE Julian Blasco, Miriam Hampel and Ignacio Moreno-Garrido... 

The presence of surfactants and their biodegradation products in different environmental compartments can invoke a negative effect on the biota. The ecotoxicity of surfactants to aquatic life has been summarised in the scientific literature [1—5]. Nevertheless, some information is still lacking in relation to the aquatic toxicity of surfactants, especially knowledge regarding the toxicity of the degradation products, the effect of surfactants on marine species, the ecotoxicity of mixtures of chemical compounds with surfactants, the relationship between toxicity and chemical residue and the effect of surfactant presence in specific environmental compartments (water, particulate matter, pore-water, sediment). 

This chapter presents a summary of the available information regarding the toxicity of surfactants in the aquatic environment and also the new data with special emphasis on the marine environment, the use of microalgae and early life-stages of fish in toxicity assays. In the last few years, one aspect related to the impact of biodegradation products of surfactants in the environment has acquired a significant relevance—the estrogenic effect—and this subject is treated in depth in Chapter 7.3 of this book. 

The mitochondrial respiratory parameters have also been employed to determine the toxicity of surfactants, including anionic (LAS), nonionic (NPEO) and their metabolites, sulfophenyl carboxylates (SPCs), NP and nonylphenoxy carboxylate (NPECi) [37]. The system employed was the in vitro response of submitochondrial particles from beef heart. The EC50 toxicity calculated as the reduction rate of NAD+ ranged from 0.61 mg L-1 for a commercial LAS mixture to 18 000 mg L-1 for SPCs, and 1.3 mg L-1, 8.2 and 1.8mgL 1 for NPEOio, NPECi and NP, respectively. These results indicate that from the toxicity perspective, LAS is the compound demanding increased attention, while for NPEO, the parental compound and the metabolites must be quantified. 

Swisher, R.D. Exposure levels and oral toxicity of surfactants. Arch. Environ. Health 1968,17, 232. 

Toxicity to Fish(14). As to the relationship between surface activity and fish toxicity of surfactants, it is said that at a surface tension of water below 48 dynes/cm fish cannot breathe through their gills, resulting in fatal toxicity due to the changes in physical properties. 

Third, the prediction model should define the chemical classes, product categories, and physical forms of test substance for which it is valid. For example, a particular alternative method may be useful (or validated) only for predicting the toxicity of surfactant-containing liquids. If so, these limitations must be defined. 

Reduced effectiveness or inhibition observed at higher surfactant concentrations Toxicity of surfactants to microorganisms 25... 

The toxicity of surfactants to marine organisms and their concentration in them depends upon their tendency to adsorb onto them and their ability to penetrate their cell membranes (Rosen, 1999). The parameter AG0ad/a, where AG°a(j is the standard free energy of adsorption of the surfactant at the aqueous solution-air interface (Chapter 2, Section IIIF) and am is the minimum cross-sectional area of the surfactant at that interface (Chapter 2, Section IIIB), was found to correlate well for several anionic and nonionic surfactants with rotifer toxicity. The same parameter was found to correlate well for a series of cationic surfactants with rotifer and green algae toxicity and, for a series of linear alkylbenzenesulfonates, with bioconcentration in fish (Rosen, 2001). 

Lewis, M. A. (1990) Chronic Toxicities of Surfactants and Detergent Builders to Algae A Review and Risk Assessment. Ecotoxicology and Environmental Safety, Vol. 20, pp. 123-140. 

Table 22.14 presents chronic toxicities of surfactants to fish, mainly restricted to various blends and homologous of LASs. Additional information comes from Table 22.15, were other anionic surfactants were tested, leading to similar results (18). 

Table 22.14. Chronic toxicities of surfactants to fish (Reproduced with permission of Hanser Verlag, Munich)...

Lewis, M. A., Chronic toxicities of surfactants and detergent builders to algae a review and risk assessment, Eco-tox. Environ. Safe, 20, 123-140 (1990). 

Lewis, M. A., The Effects of mixtures and other modifying factors on the toxicities of surfactants to freshwater and marine life. Water Res., 26, 1013-1023 (1992). 

Roberts, D. W. (1991) QSAR issues in aquatic toxicity of surfactants. Sci. Total Environ, 109/110, 557-68. 

Sandbacka, M., Christianson, L, Isomaa, B. 2000. The acute toxicity of surfactants on fish cells, Daphnia magna and fish a comparative study. Toxicology in Vitro, Vol. 14, p>p. 61-68. 

Toxicity of surfactants is also predictable. The wide range of toxicity values may seem confusing, but one must remember that surfactant structure can influence toxicity and that the standardized test methodology itself has many variables that affect toxicity values. Examples of the latter are length of testing, temperature, test water composition (e.g., hardness), species and the age of test organisms. In spite of these variables it is possible to make rationalizations and correlations and ultimately to arrive at sound judgements on the environmental safety of surfactants. 

Scholz, N. Teiiside, (1991) Environmental toxicity of. surfactants. Tensides, Surfactants and Detergents, 28, 277-281. 

Buchanan and Staniforth s [271] results on the toxicity of surfactants towards Elodea and Glycine max generally showed a decreased toxicity with increase in ethylene oxide chain length. 

Jelinek, A. Klocking, H. P. In vitro toxicity of surfactants in U937 cells cell membrane integrity and mitochondrial function. Exp. Toxicol. Pathol. 1998, 50, 472- 76. 

Table 10.3 Acute Oral Toxicity of Surfactants with a Fluorocarbon or Hydrocarbon Hydrophobe...

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