Sodium dodecyl sulphate

Long-term toxicity to aquatic invertebrates

Description of key information

NOEC (7d) = 0.88 mg/L (measured) for reproduction of Ceriodaphnia dubia (EPA-600/489/001)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.88 mg/L

Additional information

Several studies investigating the long-term toxicity of sodium dodecyl sulfate (SDS) to different aquatic invertebrate species as well as supporting chronic studies with several saltwater invertebrates are available (see Table 1).

A non-GLP, 7-day reproduction toxicity test with Ceriodaphnia dubia performed according to EPA-600/489/001 guideline is used as key study (Lauth and Dyer 1996). Daphnids were exposed under flow-through conditions to five test concentrations up to 8 mg/L. Analytical check of test concentration proved that the nominal concentrations were in agreement with the measured ones. Mortality and reproduction were evaluated daily. The 7d NOEC value for reproduction is determined to be 0.88 mg/L based on the measured concentration.

This result is supported by various additional publications investigating the long-term toxicity of sodium dodecyl sulfate to aquatic freshwater invertebrates:

LeBlanc (1982) performed a non-GLP, 40-day chronic toxicity test with Daphnia magna. The test organism was exposed to test substance concentrations up to 8 mg/L (nominal concentration) over four consecutive generations under semi-static conditions. No special guideline was followed. Offspring daphnids of less than 24 hours of age were collected after 10 days of exposure to the test substance and exposed for another 10 days. This procedure was repeated three times. The overall NOEC ranged from 2 to 4 mg/L based on nominal concentrations. Results of yet another long-term toxicity test with Daphnia magna was reported by Radix et al. (1999). The study was performed according to OECD guideline 202, part II under semi-static conditions (daily renewal) with analytical confirmation of the test substance concentration. The 21d NOEC value for reproduction is determined to be 3.2 mg/L based on the measured concentration.

Freitas & Rocha (2012) investigated the long-term toxicity of the freshwater cladoceran species Pseudosida ramosa to SDS using OECD guideline 211. SDS concentrations from 0.25 to 4 mg/L were tested under semi-static conditions. The 21d NOEC value is determined to be 1 mg/L based on the nominal concentration.

The long-term toxicity of SDS on the reproduction of Hydra attenuata was tested in a chronic toxicity test under semi-static conditions (Bode et al. 1978). The budding rate (number of buds between two feedings) was measured over an exposure time of 21 days. SDS concentrations from 5.76 to 576 mg/L were tested. A NOEC value of 5.76 mg/L is determined based on the nominal concentrations.

The reproduction inhibition of the rotifer Brachionus calyciflorus was tested in a 2d full life cycle test (Radix et al. 1999). An 2d-EC10 value is determined to be 0.98 mg/L.

 

Table 1: NOEC values from chronic toxicity tests of aquatic invertebrates with sodium dodecyl sulfate

Species	Exposure time [d]	Endpoint	NOEC [mg/L]	Reference
freshwater
Ceriodaphnia dubia	7	reproduction	0.88	Lauth & Dyer 1996
Daphnia magna	21	reproduction	3.2	Radix et al. 1999
Daphnia magna	40	mortality	2-4	LeBlanc 1982
Pseudosida ramosa	21	reproduction	1	Freitas & Rocha 2012
Hydra attenuata	21	reproduction	5.76	Bode et al. 1978
Brachionus calyciflorus	2	reproduction	0.98	Radix et al. 1999
saltwater
Mysidopsis intii	7	growth	1.41*	Harmon & Langdon 1996
Holmesimysis costata	7	mortality	1.41*	Harmon &Langdon 1996

* NOEC was converted from MATC according to ECHA guidance R.10. The most sensitive age class and endpoint is given

 

In addition, two chronic toxicity tests with saltwater species are available which similarly support the NOEC value of the key study:

7-day chronic toxicity tests according to EPA/600/4-87/028 guideline were performed with Mysidopsis intii and Holmesimysis costata (Harmon & Langdon 1996). Preliminary range-finding experiments were carried out to determine appropriate nominal test item concentrations of 1.58, 2.51, 3.97, 6.3 and 10 mg/L. The tests were performed under semi-static conditions. Different aged test organisms were tested and different endpoints measured. For Mysidopsis intii 0-7 d old mysids turned out to be the most sensitive age class and growth the most sensitive endpoint resulting in a 7d MATC value of 1.99 mg/L. The 7d NOEC value, converted from MATC according to ECHA guidance R.10, is determined to be 1.41 mg/L. For Holmesimysis costata a MATC value of 1.99 mg/L and a corresponding NOEC value of 1.41 mg/L were measured for mortality.

Based on this data set the NOEC value of 0.88 mg/L from Ceriodaphnia dubia observed in the key study was used for the hazard assessment because:

(1) it is the lowest NOEC value of all invertebrate species tested and

(2) the test is considered to be of high relevance and reliability. This assumption is based on the fact that many details about the test is available and also other alkyl sulfate homologues were tested with the same test design and organism resulting in a good comparability of the long-term toxicity of the alkyl sulfate category members to aquatic invertebrates.    

References

Bode H et al. 1978. Biological effects of surfactants, III Hydra as a highly sensitive assessment animal. Environ Pollut 17: 175-185

ECHA. 2008. Guidance on information requirements and chemical safety assessment, Chapter R.10: Characterisation of dose [concentration]-response for environment (May 2008), Helsinki, Finland

Freitas EC and Rocha O. 2012. Acute and chronic effects of atrazine and sodium dodecyl sulfate on the tropical freshwater cladoceranPseudosisa ramosa. Ecotoxicology 21: 1347-1357

Harmon VL and Langdon CJ. 1996. A 7-d toxicity test for marine pollutants using the pacific mysid Mysidopsis intii. 1. Protocoll evaluation. Environ Toxicol Chem 15(10): 1824-1830

LeBlanc GA. 1982. Laboratory investigation into the development of resistance of Daphnia magna (Straus) to environmental pollutants. Environ Pollut A 27(4): 309-322

Radix P et al. 1999. Comparison of Brachionus calciflorus 2-d and Microtox chronic 22-h tests with Daphnia magna 21-d test for the chronic toxicity assessment of chemicals. Environ Toxicol Chem 18(10): 2178-2185