Sodium 2-sulphonatoethyl laurate

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

06-12-1993 to 03-01-1994

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Guideline study, summarily described, No GLP, no CoA i.e. no data on impurities, but biodeg monitored based on DOC data. Result sufficient as supporting study. 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 301 E (Ready biodegradability: Modified OECD Screening Test)

Deviations:

yes

Remarks:

Number of replicates of test substance and reference substance is lower than required.

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Inoculum: activated sludge
Sample location: Sewage treatement plant Niederrad
number of viable micro-organisms: about 10^6 CFU
Pretreatment of inoculum: 1 day aerated befor use
Adaption : Not adapted to test substance
die Referenzsubstanz adaptiert

Duration of test (contact time):

28 d

Initial conc.:

30 mg/L

Based on:

test mat.

Initial conc.:

13.85 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

Test incubation at 20 ± 2 °C.
Test media according to OECD 301 E.
Sodium benzoate is used as reference substance and control without test substance is included
Test vessels: 1 L glas roundflasks covered with aluminium foil.
Test was performed without aeration.
Test was performed in the dark on a shaker.

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (DOC removal)

Value:

94.1

Sampling time:

28 d

Details on results:

No inhibition control was included in the test but based on the degradation of the test substance no inhibition of degradation was observed.

Results with reference substance:

OK

Time	Control	Sodium benzoate		Sodium Cocoyl Isethionate
days	DOC (mg/L)	DOC (mg/L)	% degraded	DOC (mg/L)	% degraded
0	0.3/0.3	20.3	-	13.85	-
7	0.3/0.3	2.0	91.5	1.15	93.7
14	0.3/0.3	1.2	95.5	1.10	94.1
21	0.3/0.3	0.8	97.5	1.60	90.4
28	0.3/0.3	0.8	97.5	1.10	94.1

Validity criteria fulfilled:

yes

Remarks:

endogenous respiration acceptable, reference test result OK

Interpretation of results:

readily biodegradable

Conclusions:

Despite the very limited description the test result is considered valid with an acceptable reliability

Executive summary:

The ready biodegradability of sodium cocoyl isethionate has been demonstrated in an OECD 301E test. The test is considered valid but relatively summarily described. Not performed under GLP conditions and details on the quality of the test substance is missing. The result can be used as supporting study.

Description of key information

Based upon read-across to Coco fatty acids 2-sulfoethyl ester, sodium salt, the lauric acid 2-sulfoethyl ester, sodium salt is considered to be readily biodegradable. Coco fatty acids 2-sulfoethyl ester, sodium salt is a UVCB substance and therefore was the 10-day windows not evaluated. No toxicity to the inoculum was observed at 1.62 mg a.i./L

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

There is no biodegradation screening 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 rated Klimisch 2 and was carried out according to the OECD guideline 301E, as described in Bueckling and Pleschke, 1994.

The ready biodegradability of the test substance was determined in three different tests. Coco fatty acids 2 -sulfoethyl ester, sodium salt was found to be readily biodegradable in all three tests. In the key study by Buecking and Pleschke , a Closed Bottle test according to the slightly modified OECD, EEC and ISO test guidelines under GLP conditions is described and 94.1% degradation was observed at 14 and 28 days. No toxicity to the inoculum was observed. 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.