Sodium 2-sulphonatoethyl laurate

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

04-08-1994

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Non GLP, Guideline study, sufficiently described, no CoA but some details like active ingredient content on the test substance in the report. Read-across is based upon a commonality of functional groups, constituents, breakdown products and metabolic pathways. A detailed justification is appended in Section 13.

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The test substance was weighed directly into the test vessels due to the limited solubility in water. The test solutions were before the start of the test for 30 minutes ultrasonically treated. 4 mg of Antifoam (SE-2) was added to each test vessel with test substance.

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Dry weight in the test: 1600 mg/L
Origin of inoculum: Kommunale Abwasserreinigungsanlage Frankfurt/MSindlingen.
Pretreatment of sludge: according to the OECD guideline
Adaptation of the sludge: Not adapted

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

20 ± 2 °C

pH:

7.2 ± 0.2

Salinity:

According to OECD 209 guideline

Details on test conditions:

Reference substance concentration: 5, 20 und 30 mg/L
Test substance concentrations: 62.5 to 1000 mg/L

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

3 h

Dose descriptor:

other: EC20

Effect conc.:

639 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Results with reference substance (positive control):

Results for the reference substance and control were within the required limits.

Validity criteria fulfilled:

yes

Conclusions:

The test is not performed under GLP conditions but the results are considered reliable and valid. This result is therefore adequate for evaluating the hazard of coco fatty acids 2-sulfoethyl ester, sodium salt to sludge bacteria.

Executive summary:

The median effect of coco fatty acids 2 -sulfoethyl ester, sodium salt the respiration of microorganisms present in activated sludge was observed to be >1000 mg/L.

Description of key information

The 3h-EC50 for activated sludge was > 687 mg/L and the 3h-EC20 was 439 mg/L in a respiration inhibition test with OECD Test Guideline 209 under GLP (concentration based on active ingredient).

Key value for chemical safety assessment

EC50 for microorganisms:

687 mg/L

Additional information

There is no activated sludge, respiration inhibition test available for lauric acid 2-sulfoethyl ester, sodium salt (sodium lauroyl isethionate) CAS No 7381-01-3. 

There is however a study on the source chemical Coco fatty acids 2 -sulfoethyl ester, sodium salt CAS no 61789 -32 -0, which is Klimisch rated 2 and was carried out according to the OECD guideline 209 , described in Reinhardt ,1994.

The toxicity to activated sludge was determined in a respiration inhibition test in accordance with OECD Test Guideline 209. The toxicity of the sodium salt of coco fatty acids 2 -sulfoethyl ester to activated sludge was determined at a contact time of 3 hours, using various concentrations of the test substance. The EC50 was reported as >1000 mg/L of test substance which corresponds with > 687 mg/L based on active ingredient concentration. The EC20 was 639 mg/L based on test material which corresponds with 439 mg/L base on active ingredient concentration. The substance is therefore considered not harmful to activated sludge (Reliability 2). Read-across from the source chemical,Coco fatty acids 2 -sulfoethyl ester, sodium salt CAS no 61789 -32 -0 to the target chemical is considered to be justified based upon a commonality of functional groups, constituents, breakdown products and metabolic pathways.

Therefore we consider these study endpoint results as sufficiently conservative to be taken account of in the risk assessment of lauric acid 2-sulfoethyl ester, sodium salt (sodium lauroyl isethionate) CAS No 7381-01-3.