Sodium 2-sulphonatoethyl laurate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Start date 14/05/84, finish date 18/05/84, report date 16/07/84

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP compliant and OECD equivalent. Based on nominal and measured concentrations but limited supporting analytical data. 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:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not applicable

Analytical monitoring:

yes

Details on sampling:

Concentrations of certain selected test solutions were determined at 0, 48 and 96 hours according to the methylene blue method , however because of precipitation problems, additional pre-analytical treatment was required for some samples in order to obtain a satisfactory determination, i.e. the 48 hr (old) samples were first analysed with precipitate present and then analysed again after the additional solubilising treatment.
The temperature, pH, dissolved oxygen and total hardness (as mg/L CaC03) of the analysed test solution concentrations were also measured.

See appendex 1!!

Vehicle:

yes

Details on test solutions:

The test solutions are prepared by adding the appropriate amount of stock solution to each tank by pipette or measuring cylinder depending on volume and filling up to about 1" below the 10 litre mark with URPSL carbon filtered tap water, (renewal solutions are made up to the 10 litre mark at
once), the missing volume allows for addition of the fish in 500 mLs -1 litre before final volumes are made up without dilution of the test
liquors.

Both sets of test vessels are labelled and when the 0 hour test solutions are prepared they are left covered and aerating on the shelves in the temperature controlled room. The temperature of the starvation tank and the test solutions are checked.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Source: Chirk fish Hatchery, Nr Wrexham 29/03/84
- Age at study initiation (mean and range, SD): ~4 months
- Feeding during test
- Food type: commercial trout food
- Amount: equivalent to about 5% total bodyweight
- Frequency: 4-5 times a day


ACCLIMATION
- Acclimation period: 29/03/84- 09/04/84
- Acclimation conditions (same as test or not): same as test
- Type and amount of food: see above
- Feeding frequency: see above
- Health during acclimation (any mortality observed): The cumulative mortality during the acclimation period was high (14%) but fell to 2.8% over the 7 day period 21.4.84 to 28.4.84. The mortality rate is therefore well below the maximum permissab1e value of 5% over 7 days.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

Not applicable

Hardness:

118+/-8 mg/L CaCO3

Test temperature:

12.2+/-0.6 °C

pH:

8.0+/-0.2

Dissolved oxygen:

9.2+/- 0.8 mg/L

Salinity:

N/A

Nominal and measured concentrations:

Nominal 0.0*, 3.2*, 5.6, 10.0*, 18.0, 32.0, 100.0* mg/L
Measured: see table below

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): CLOSED
- Material, size, headspace, fill volume: 10 L, GLASS
- Aeration: Continuous
- Type of flow-through (e.g. peristaltic or proportional diluter): none
- Renewal rate of test solution (frequency/flow rate): every 48hrs
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2 vessels per concentration
- No. of vessels per control (replicates): 2 vessels
- No. of vessels per vehicle control (replicates): same as control
- Biomass loading rate: no data


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Unilever carbon filtered tap water
- Total organic carbon: N/A
- Particulate matter: N/A
- Metals: NO DATA
- Pesticides: NO DATA
- Chlorine: NO DATA
- Alkalinity: NO DATA
- Ca/mg ratio: NO DATA
- Conductivity: NO DATA
- Culture medium different from test medium: NO
- Intervals of water quality measurement: 0 , 48, 96 Hrs


OTHER TEST CONDITIONS
- Adjustment of pH: NO
- Photoperiod: 16 hrs
- Light intensity: NO DATA


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality


TEST CONCENTRATIONS
- Spacing factor for test concentrations: no data
- Justification for using less concentrations than requested by guideline: N/A
- Range finding study N/A

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 25 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

There were no deaths in any of the concentrations except in the highest (100 mg/L) where only 10% (2 out 10 in tank 14) mortality occurred. The 96 hour LC50 of Defi to 4 month old feeding rainbow trout fry must therefore be greater than the maximum concentration remaining in the test liquor after 96 hours. This concentration is approximately 25 mg/L.

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

Statistical analysis of percentage mortality data will be performed by the methods put forward by Stephan 1977. Three methods of calculating the LC50 will be used:-
(1) Binomial ± 95% confidence limits
(2) Moving average ± 95% confidence limits
(3) Probit ± 95% confidence limits.

Conclusions:

Analytical results indicate that Defi is rapidly lost from the test liquor. As foaming was not observed in any tank and as the additional pre-treatment
made the remaining test compound available for analysis, it is most probable that the compound was biodegraded.

There were no deaths in any of the concentrations except in the highest (100 mg/L) where only 10% mortality occurred. The 96 hour LC50 of Defi
to 4 month old feeding rainbow trout fry must therefore be greater than the maximum concentration remaining in the test liquor after 96 hours.
This concentration is approximately 25-30 mg/L

Executive summary:

Analytical results indicate that Defi is rapidly lost from the test liquor. As foaming was not observed in any tank and as the additional pre-treatment made the remaining test compound available for analysis, it is most probable that the compound was biodegraded.

There were no deaths in any of the concentrations except in the highest (100 mg/L) where only 10% mortality occurred. The 96 hour LC50 of Defi to 4 month old feeding rainbow trout fry must therefore be greater than the maximum concentration remaining in the test liquor after 96 hours. This concentration is approximately 25-30 mg/L

Description of key information

The 96h-LC50 to Salmo gairdneri  (rainbow trout) is >9.9 mg/L in an OECD 203 test under GLP (Reliablity 2) based on active ingredient concentration.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

9.9 mg/L

Additional information

There is no acute fish toxicity study available for lauric acid 2-sulfoethyl ester, sodium salt (sodium lauroyl isethionate) CAS No 7381-01-3. 

There is however studies on the source chemical Coco fatty acids 2 -sulfoethyl ester, sodium salt CAS no 61789 -32 -0, which are rated Klimisch 2 and were carried out according to the OECD guideline 203 under GLP as described in Unilever study AT-RS43 -01, 1984.

The toxicity of the sodium salt of 2-sulfoethyl ester of coco fatty acid to fresh water fish has been assessed in two reliable with restrictions tests. In all tests precipitation occured during the test. In one test where rainbow trout were semi-statically exposed to nominal concentrations of 0, 3.2, 10 and 100 mg/L, the exposure concentrations were quantified. The observed 96h LC50 in this test is >16.5 mg a.i./L based measured initial test concentration and > 9.9 mg a.i./L based on geometrical mean measured test concentration. This value of 9.9 mg a.i./L is as a worst-case used for risk assessment and Classification and labelling according to EU CLP criteria. 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.