Sodium (xylenes and 4-ethylbenzene)sulfonates

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Remarks:

No original study report available, not to GLP, no analytical analysis of test concentrations, limited information available from secondary sources, the data produced is thought to be insufficient to statistically derive a NOEC

Qualifier:

equivalent or similar to guideline

Guideline:

other: UBA Verlaengerter Toxizitaetstest bei Daphnia magna nach UBA (1984 standard)

Version / remarks:

1984 standard

Deviations:

yes

Remarks:

Unable to compare to test guidelines, however no analytical confirmation of test chemicals is included

GLP compliance:

no

Remarks:

Stated that the study was conducted in 1987 without formal GLP, however the laboratory received GLP accreditation in 1989/1990

Specific details on test material used for the study:

CAS no: 28348-53-0No further details provided

Analytical monitoring:

no

Vehicle:

not specified

Details on test solutions:

No further details provided

Test organisms (species):

Daphnia magna

Details on test organisms:

No further details provided

Test type:

not specified

Water media type:

not specified

Limit test:

no

Total exposure duration:

21 d

Post exposure observation period:

Not included

Hardness:

No details provided

Test temperature:

No details provided

pH:

No details provided

Dissolved oxygen:

No details provided

Salinity:

No details provided

Conductivity:

No details provided

Nominal and measured concentrations:

Nominal concentrations: 30, 100 and 300 mg/L active ingredient

Details on test conditions:

No further details provided on the test conditions.

Reference substance (positive control):

not specified

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

< 30 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Remarks:

number of offspring

Remarks on result:

other:

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

ca. 154 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Remarks:

number of offspring

Details on results:

For the NOEC for reproduction, there is some discrepancy between the value provided in each of the 3 literature sources. Greim et al (1994) state a NOEC of > 30 mg/L, however the HULS AG document states a NOEC of < 30 mg/L and the HERA Hydrotopes September 2005 document considers a NOEC of > 30mg/L an error based on the data, however the NOEC is most likely to be <30mg/L or 30mg/L. Further details are provided below based on the evaluation of the data provided in the HERA Hydrotopes document.For the NOEC for reproduction, it is indicated the HERA Hydrotropes September 2005 literature source, that the NIOEC relates to the number of offspring produced during the study period. None of the literature sources include the raw data, however this report states 'the average number of offspring produced per day was 43 in the controls, 38 at 30 mg/L, 29 at 100 mg/L and 13 at 300 mg/L, which equate to 88% of control, 67% of control and 30% of control at 30, 100 and 300 mg/L respectively'. There is not considered sufficient data to be able to establish a statistically derived NOEC and it is uncertain whether 88% of the control is a significant

Results with reference substance (positive control):

Not applicable

Validity criteria fulfilled:

not specified

Conclusions:

The long term chronic NOEC for reproductive output in Daphnia magna is <30 mg/L, equal to or >30 mg/L. The LC50 for reproduction is 154 mg/L.

Executive summary:

A long term chronic study was carried out on Daphnia magna, to determine the potential effects of sodium cumene sulfonate on reproduction. The study was carried out according to the UBA Verlaengerter Toxizitaetstest bei Daphnia magna nach UBA (1984 standard), however it has not been possible to compare the study details with these guidelines. The study was not conducted according to GLP. Details on the study have been compiled based on three information sources (two secondary literature sources and one publication), however details on the study conditions, methodology and results is lacking and based on this the study is considered a reliability klimisch 4 rating.

The available information indicate Daphnia magna were exposed to the test substance for 21 days, at three nominal concentrations of 30, 100 and 300 mg/L in addition to controls. No further details are provided on the test set up. No increased mortality was observed in the Daphnia magna adults, however a decrease in the number of offspring produced was noted at all test concentrations.

The HERA Hydrotopes document states 'the average number of offspring produced per day was 43 in the controls, 38 at 30 mg/L, 29 at 100 mg/L and 13 at 300 mg/L, which equate to 88% of control, 67% of control and 30% of control at 30, 100 and 300 mg/L respectively. Discrepancies exist in the 3 literature sources between the exact NOEC value and one of the reports state the available information is considered insufficient to be able to establish a statistically derived NOEC and it is uncertain whether the 88% reduced reproductive output compared to the control observed in the 30mg/L concentration, is a significant reduction. However, based on a worst case scenario, it is assumed the NOEC is <30 mg/L and the LC50 is 154 mg/L.

Description of key information

The HYDROTOPES Category comprises the following 6 substances:
STS - Sodium toluene sulphonate (CAS 657-84-1, EC 211-522-5)
SXS - Sodium (xylenes and 4-ethylbenzene) sulphonate (EC 701-037-1)
NH4XS - Ammonium (xylenes and 4-ethylbenzene) sulphonate (EC 943-024-5)
SCS - Sodium cumene sulphonate (CAS 15763-76-5, EC 239-854-6)
KCS - Potassium cumene sulphonate (CAS 164524-02-1, EC 629-764-9)
NH4CS - Ammonium cumene sulphonate (CAS 37475-88-0, 253-519-1) 
In addition CaXS (Calcium Xylenesulphonate, CAS 28088-63-3, EC248-829-9)was evaluated for complete the assessment despite it is not registered under REACH.

An environmental risk assessment has indicated that the members of the Hydrotropes category do not pose a risk to the aquatic environment for all relevant uses. In Annex IX of Regulation (EC) No 1907/2006 it is laid down that chronic toxicity tests shall be proposed by the registrant if the chemical safety assessment indicates the need to investigate further. There are availbale acute tests on the three hydrotropes subgroups (toluene, xylene and cumene) which did not show any concern for all the three thropic levels. Since the chronic testing would not change the outcome of the environmental risk assessment the additional chronic testing on aquatic invertebrates appears to be unjustified. One chronic test on invertebrates is reported in literature (Huls, 1987), but is considered of poor reliability (Klimisch 4). The study indicates a long term chronic toxicity of sodium cumene sulfonate to Daphnia magna of a NOEC of <30 or 30 mg/L and an LC50 of 154 mg/L. Use of these data, would not change the outcome of the environmental risk assessment and are provided for completeness only. As acute toxicity was not observed at the concentrations tested in the acute studies and the hydrotrope category members are readily biodegradable, no additional chronic testing on aquatic invertebrates is required and this endpoint is waived.