Sulfonic acids, C16-alkane hydroxy and C16-alkene, sodium salts

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

Study reported in published scientific literature. Description of relevant basic data.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

Instead of the species D. magna, the species Ceriodaphnia dubia Richard was used. Both share the same family (Daphniidae) but instead of the Genus Daphnia, the Genus Ceriodaphnia. Other test parameter seem to be congruent.

Principles of method if other than guideline:

other species (see above)

GLP compliance:

no

Specific details on test material used for the study:

only reported data on test substance:
Sodium C14-16 alpha olefin sulfonate
CAS:68439-57-6
MW: 324.00
"provided by detergent manufacturer"

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION

Stock solutions of each component were made by dissolving the appropriate amount in 1 or 2 L of the water and then gently stirred for 12 h in the dark at 23±1°C using Teflon magnetic stirrers.
Stirring was conducted so that no bubbles were formed when the surfactants were dissolved, as the formation of bubbles leads to depletion of surfactants in the solution (Aboul-Kassim and Simoneit, 1993).
Light was excluded during the stirring to minimize photodegradation of the chemicals.
Stock solutions were diluted to the appropriate concentrations immediately prior to the commencement of a test.

Test organisms (species):

Ceriodaphnia dubia

Details on test organisms:

TEST ORGANISM

- Strain/clone: C. dubia Richard


ACCLIMATION
C. cf. dubia were cultured and tested at 23$13C in dechlorinated Sydney mains water which was "ltered (1 􏰇m), aged (1 month), and adjusted to 500 􏰇S/cm with seawater. Cultures of C. cf. dubia were maintained in 2-L glass beakers and transferred to fresh water three times weekly. Food was provided after water renewal at a concen- tration of 25,000 cells/ml of each of the unicellular algae Pseudokirchneriellia subcapitata Printz (formerly named Se- lenastrum capricornutum) and Ankistrodesmus sp. All neon- ates used in the toxicity tests were less than 24 h old.

Test type:

static

Water media type:

not specified

Remarks:

in the publication reference is made to a former publication (without naming the exact publication)

Limit test:

no

Total exposure duration:

48 h

Test temperature:

23 ±1 °C

Details on test conditions:

TEST SYSTEM
- Test vessel:
250-ml glass beaker with 200-ml test solution

- No. of organisms per vessel: 5

- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3


OTHER TEST CONDITIONS
- Photoperiod: 16:8-h light to dark
- Light intensity: below 1000 lx at the surface of the solutions

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobilisation
(absence of visible movement by the cladocera within 15 s of gentle agitation of the test solution (ASTM, 1988).)

Range-finder
was made;
If the resulting EC values were markedly di!erent, a second de"nitive test was conducted

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

4.53 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CL: 4.14-4.95

Validity criteria fulfilled:

yes

Conclusions:

For Sodium C14-16 alpha olefin sulfonate (CAS 68439-57-6) the 48h-EC50 = 4.53 mg/L for the vertebrate species Ceriodaphnia dubia Richard.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 December 2014 to 14 May 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Study conducted to OECD and EC guidelines and in compliance with GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Expiration date: August 1, 2016

Analytical monitoring:

yes

Details on sampling:

Samples were taken from the control and each test group from the bulk test preparation at 0 hours and from the pooled replicates at 48 hours for quantitative analysis. All samples were stored frozen prior to analysis. Duplicate samples were taken at 0 and 48 hours and stored frozen for further analysis if necessary.

Vehicle:

no

Details on test solutions:

Reconstituted water (ISO medium) was used for both the range-finding and definitive tests.

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna is a freshwater invertebrate representative of a wide variety of natural habitats, and can therefore be considered as an important non-target organism in freshwater ecosystems.The test was carried out using 1st instar Daphnia magna derived from in-house laboratory cultures.

Adult daphnia were maintained in 150 mL glass beakers containing Elendt M7 medium in a temperature controlled room at approximately 20°C. The lighting cycle was controlled to give a 16 hours light and 8 hours darkness cycle with 20 minute dawn and dusk transition periods. Each culture was fed daily with a mixture of algal suspension (Desmodesmus subspicatus) and Tetramin® flake food suspension. Culture conditions ensured that reproduction was by parthenogenesis. Gravid adults were isolated the day before initiation of the test, such that the young daphnids produced overnight were less than 24 hours old. These young were removed from the cultures and used for testing. The diet and diluent water are considered not to contain any contaminant that would affect the integrity or outcome of the study.

Test type:

static

Water media type:

other: Reconstituted Water – ISO Medium

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20 - 21 °C

pH:

7.7 - 8.2

Dissolved oxygen:

8.8 - 9.0

Nominal and measured concentrations:

Nominal concentrations: 1.0, 1.8, 3.2, 5.6, 10 mg active ingredient/L

Measured concentrations at 0 h: 0.721, 1.16, 2.55, 4.27, 8.53 mg active ingredient/L
Measured concentrations at 48 h: 0.682, 1.09, 2.18, 4.57, 8.44 mg active ingredient/L

Details on test conditions:

The test concentrations to be used in the definitive test were determined by a preliminary range-finding test.

In the range-finding test Daphnia magna were exposed to a series of nominal test concentrations of 0.10, 1.0, 10 and 100 mg ai/L. At the request of the Sponsor all test concentrations were corrected for a test item purity value of 28.6% w/w. Prior to use, the test item was heated at 70 °C and mixed thoroughly in order to ensure homogeneity.

A nominal amount of test item (1748.3 mg) was dissolved in deionized reverse osmosis water and the volume adjusted to 500 mL to give a 1000 mg ai/L stock solution. A series of dilutions was performed in test water to give the test series.

The stock solution and each prepared concentration were inverted several times to ensure adequate mixing and homogeneity.

In the range-finding test 10 daphnids were placed in each test and control vessel and maintained in a temperature controlled room at approximately 20 C with a photoperiod of 16 hours light and 8 hours darkness for a period of 48 hours with 20 minute dawn and dusk transition periods. Each 250 mL test and control vessel contained 200 mL of test media and was covered to reduce evaporation. After 24 and 48 hours the number of immobilized daphnids were recorded.

The control group was maintained under identical conditions but not exposed to the test item.

A sample of each test concentration was taken for chemical analysis at 0 and 48 hours in order to determine the stability of the test item under test conditions. All samples were stored frozen prior to analysis. Only concentrations within the range to be used for the definitive test were analyzed.



Based on the results of the range-finding test the following test concentrations were assigned to the definitive test: 1.0, 1.8, 3.2, 5.6 and 10 mg ai/L.

-Experimental Preparation
At the request of the Sponsor all test concentrations were corrected for a test item purity value of 28.6% w/w. Prior to use the test item was heated to approximately 70 °C and mixed thoroughly in order to ensure homogeneity.

A nominal amount of test item (174.8 mg) was dissolved in deionized reverse osmosis water and the volume adjusted to 500 mL to give a 100 mg ai/L stock solution. Dilutions were performed in test water to give the test series.

The stock solution and each prepared concentration was inverted several times to ensure adequate mixing and homogeneity.

The concentration and stability of the test item in the test preparations were verified by chemical analysis at 0 and 48 hours.

-Exposure Conditions
As in the range-finding test 250 mL glass jars containing approximately 200 mL of test preparation were used. At the start of the test 5 daphnids were placed in each test and control vessel at random, in the test preparations. Four replicate test and control vessels were prepared. The test vessels were then covered to reduce evaporation and maintained in a temperature controlled room at approximately 21 C with a photoperiod of 16 hours light (604 to 664 lux) and 8 hours darkness with 20 minute dawn and dusk transition periods. The daphnids were not individually identified, received no food during exposure and the test vessels were not aerated.

The control group was maintained under identical conditions but not exposed to the test item.

The test preparations were not renewed during the exposure period.


-Evaluations
Test Organism Observations
Any immobilization or adverse reactions to exposure were recorded at 24 and 48 hours after the start of exposure. The criterion of effect used was that daphnia were considered to be immobilized if they were unable to swim for approximately 15 seconds after gentle agitation.

Water Quality Criteria
Water temperature was recorded daily throughout the test. Dissolved oxygen concentrations and pH were recorded at the start and termination of the test. The pH and dissolved oxygen concentration were measured using a Hach HQ30d Flexi handheld meter whilst the temperature was measured using a Hanna Instruments HI 93510 digital thermometer.

-Statistical Analysis
The EC50 values and associated confidence limits at 0 and 48 hours were calculated by Probit analysis using maximum likelihood regression. All statistical analysis was conducted using the TOXRAT PROFFESIONAL computer program (2001 – 2010).


The results of the test are considered valid if the following performance criteria are met:

• No more than 10% of the control daphnids show immobilization or other signs of disease or stress (e.g. discoloration or unusual behavior such as trapping at the surface water).
• The dissolved oxygen concentration at the end of the test is ≥3 mg/L in the control and test vessels.

Reference substance (positive control):

yes

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

1.1 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Details on results:

No significant immobilization was observed at the test concentrations of 0.10 and 1.0 mg ai/L. However, immobilization was observed at 10 and 100 mg ai/L.

Single immobilized daphnids were observed in the control and 0.10 mg ai/L test group, however, as no more than 10% immobilization was observed and no immobilization was observed at the higher concentration of 1.0 mg ai/L, this was considered to be due to natural causes and was considered not to have had an impact on the outcome of the test.

Based on this information test concentrations of 1.0, 1.8, 3.2, 5.6 and 10 mg ai/L were selected for the definitive test.

Chemical analysis of the test preparations at 0 and 48 hours showed inconsistencies; therefore samples were prepared in the same way as during the range finding test in order to determine the stability of the test item under test conditions. Results showed that measured concentrations of between 60% and 84% of nominal were obtained, indicating that the test item was stable under test conditions.



-Verification of Test Concentrations
Analysis of the test preparations at 0 and 48 hours showed measured test concentrations to range from 61% to 85% of nominal value. There was no significant difference between the 0 and 48-Hour results, therefore the results are based on the 0-Hour measured concentrations.

-Immobilization Data
Analysis of the immobilization data by Probit analysis using maximum likelihood regression at 0 and 48 hours based on the 0-Hour measured concentrations gave the following results:

48-h EC50: 1.1 mg ai/L (95% Confidence limits: 0.98 – 1.2 mg ai/L)

All analysis was conducted using the TOXTRAT PROFFESIONAL computer program (2001 – 2010).

-Observations on Test Item Solubility
At 0 hours, the 1.0, 1.8 and 3.2 mg ai/L test preparations were observed to be clear colorless solution, whilst the 5.6 and 10 mg ai/L test preparations were observed to be clear colorless solutions with a small amount of foam on the surface. For the remainder of the test, all of the test preparations were observed to be clear colorless solutions.

-Validation Criteria
The test was considered to be valid give that no more than 10% of the control daphnids showed immobilization or other signs of disease or stress and that the oxygen concentration at the end of the test was ≥3 mg/L in the control and test vessels.

Results with reference substance (positive control):

A positive control (Harlan Study Number 41500252) used potassium dichromate as the reference item at concentrations of 0.32, 0.56, 1.0, 1.8 and 3.2 mg/L. The positive control was conducted between 23 February 2015 and 25 February 2015.

Exposure conditions for the positive control were similar to those in the definitive test.

Analysis of the immobilization data at 24 and 48 hours by probit analysis using linear maximum likelihood regression based on the nominal test concentrations gave the following results:

48-h EC50: 0.75 mg/L (95% Confidence Limits: 0.69 - 0.82 mg/L)

All analysis was carried using the ToxRat Professional computer software package (ToxRat) **.

The results from the positive control with potassium dichromate were within the normal range for this reference item.

See attached fugures and tables for more details.

Validity criteria fulfilled:

yes

Conclusions:

Analysis of the immobilization data by Probit analysis using maximum likelihood regression at 0 and 48 hours based on the 0-Hour measured concentrations gave the following results:

48-h EC50: 1.1 mg ai/L (95% Confidence limits: 0.98 – 1.2 mg ai/L)

Executive summary:

INTRODUCTION

A study was performed to assess the acute toxicity of the test item to Daphnia magna. The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (April 2004) No 202.

 

METHODS

Following a preliminary range-finding test, twenty daphnids (4 replicates of 5 animals) were exposed to an aqueous solution of the test item at concentrations of 1.0, 1.8, 3.2, 5.6 and 10 mg active ingredient (ai)/L for 48 hours at a temperature of approximately 21°C under static test conditions. The numbers of immobilized daphnia were recorded after 24 and 48 hours.

 

RESULTS

Analysis of the test preparations at 0 and 48 hours showed measured test concentrations to range from 61% to 85% of nominal value. There was no significant difference between the 0 and 48-Hour results, therefore the results are based on the 0-Hour measured concentrations.

 

Exposure of Daphnia magna to the test item gave the following results:

48-h EC50: 1.1 mg ai/L (95% Confidence limits: 0.98 – 1.2 mg ai/L)

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
This read-across is based on the hypothesis that source and target substances have similar (eco)toxicological properties because
Source and target substances share structural similarities (predominantly linear aliphatic hydrocarbon chain) with a common functional group: (polar sulfonate group). The molecular structure is almost identical.
They are manufactured from similar resp. identical precursors under similar conditions. Therefore, common breakdown products via physical and biological processes, which result in structurally similar chemicals are evident. Target and source substances are both a mixture of linear long chain Sulfonic acids, alkene, sodium salts and Sulfonic acids, alkane hydroxy, sodium salts and share an identical counter ion. A constant pattern in the changing of the potency of the properties across the target and source substances by chain-length and is not observed, because the distribution is too narrow.

Therefore, read-across from the existing toxicity studies on the source substance, is considered as an appropriate adaptation to the standard information requirements of Annex VII, 8.1, 8.2, 8.3, 8.4, 8.5 as well as 9.1 and 9.2 of the REACH Regulation for the target substance, in accordance with the provisions of Annex XI, 1.5 of the REACH Regulation.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
see cross reference to assessment report: Justification for read-across document attached to section 13

3. ANALOGUE APPROACH JUSTIFICATION
see cross reference to assessment report: Justification for read-across document attached to section 13

4. DATA MATRIX
see cross reference to assessment report: Justification for read-across document attached to section 13

Reason / purpose for cross-reference:

read-across: supporting information

Reason / purpose for cross-reference:

read-across: supporting information

Reason / purpose for cross-reference:

read-across source

Vehicle:

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

1.1 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Details on results:

No significant immobilization was observed at the test concentrations of 0.10 and 1.0 mg ai/L. However, immobilization was observed at 10 and 100 mg ai/L.

Single immobilized daphnids were observed in the control and 0.10 mg ai/L test group, however, as no more than 10% immobilization was observed and no immobilization was observed at the higher concentration of 1.0 mg ai/L, this was considered to be due to natural causes and was considered not to have had an impact on the outcome of the test.

Based on this information test concentrations of 1.0, 1.8, 3.2, 5.6 and 10 mg ai/L were selected for the definitive test.

Chemical analysis of the test preparations at 0 and 48 hours showed inconsistencies; therefore samples were prepared in the same way as during the range finding test in order to determine the stability of the test item under test conditions. Results showed that measured concentrations of between 60% and 84% of nominal were obtained, indicating that the test item was stable under test conditions.



-Verification of Test Concentrations
Analysis of the test preparations at 0 and 48 hours showed measured test concentrations to range from 61% to 85% of nominal value. There was no significant difference between the 0 and 48-Hour results, therefore the results are based on the 0-Hour measured concentrations.

-Immobilization Data
Analysis of the immobilization data by Probit analysis using maximum likelihood regression at 0 and 48 hours based on the 0-Hour measured concentrations gave the following results:

48-h EC50: 1.1 mg ai/L (95% Confidence limits: 0.98 – 1.2 mg ai/L)

All analysis was conducted using the TOXTRAT PROFFESIONAL computer program (2001 – 2010).

-Observations on Test Item Solubility
At 0 hours, the 1.0, 1.8 and 3.2 mg ai/L test preparations were observed to be clear colorless solution, whilst the 5.6 and 10 mg ai/L test preparations were observed to be clear colorless solutions with a small amount of foam on the surface. For the remainder of the test, all of the test preparations were observed to be clear colorless solutions.

-Validation Criteria
The test was considered to be valid give that no more than 10% of the control daphnids showed immobilization or other signs of disease or stress and that the oxygen concentration at the end of the test was ≥3 mg/L in the control and test vessels.

Results with reference substance (positive control):

A positive control (Harlan Study Number 41500252) used potassium dichromate as the reference item at concentrations of 0.32, 0.56, 1.0, 1.8 and 3.2 mg/L. The positive control was conducted between 23 February 2015 and 25 February 2015.

Exposure conditions for the positive control were similar to those in the definitive test.

Analysis of the immobilization data at 24 and 48 hours by probit analysis using linear maximum likelihood regression based on the nominal test concentrations gave the following results:

48-h EC50: 0.75 mg/L (95% Confidence Limits: 0.69 - 0.82 mg/L)

All analysis was carried using the ToxRat Professional computer software package (ToxRat) **.

The results from the positive control with potassium dichromate were within the normal range for this reference item.

See attached figures and tables for more details.

Validity criteria fulfilled:

yes

Conclusions:

Analysis of the immobilization data by Probit analysis using maximum likelihood regression at 0 and 48 hours based on the 0-Hour measured concentrations gave the following results:

48-h EC50: 1.1 mg ai/L (95% Confidence limits: 0.98 – 1.2 mg ai/L)

Reference 4

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE
EPI Suite v4.11

2. MODEL (incl. version number)
ECOSAR Program (v1.11)

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
please see attachment

5. APPLICABILITY DOMAIN
please see attachment

6. ADEQUACY OF THE RESULT
The result supports the use of read-across for this endpoint.
The read-across source substance has higher or even toxicity to daphnia compared to the target substance.
For details please see attachment

Principles of method if other than guideline:

please see attachment under "attached justification"

Specific details on test material used for the study:

Structures used:
HO-C18H36-SO3Na and HO-C16H32-SO3Na
for details see QMRF attached

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

0.18 mg/L

Remarks on result:

other: Target substance C16 IOS-Na (ECOSAR Class: Alkyl, Sulfonates)

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

0.18 mg/L

Remarks on result:

other: Source substance C16-18 IOS-Na C18-rich (ECOSAR Class: Alkyl, Sulfonates)

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

86.346 mg/L

Remarks on result:

other: Target substance C16 IOS-Na (ECOSAR Neutral Organics-acid)

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

13.482 mg/L

Remarks on result:

other: Source substance C16-18 IOS-Na C18-rich (ECOSAR Neutral Organics-acid)

Conclusions:

as proved according to ECOSAR QSAR for the main structure of IOS, the toxicity to daphnia of the source substance 3 (C16-18 IOS-Na C18-rich) is higher or equal to the toxicity of the target substance (C16 IOS-Na).

Executive summary:

ECOSAR for the two linear (main) structures (difference only in C-chain length) of target (C16) and source 3 (C18 (one structure of the mixture)) shows

• even ecotoxicity to daphnia for the C18 compared to the C16 structure in the ECOSAR “special classes” – surfactants – alkyl sulfonates.


• higher ecotoxicity to daphnia for the C18 compared to the C16 structure in the ECOSAR neutral organics acid.

 

As a conclusion, as proved according to ECOSAR QSAR for the main structure of IOS, the toxicity to daphnia of the source substance 3 (C16-18 IOS-Na C18-rich) is higher or equal to the toxicity of the target substance (C16 IOS-Na).

Description of key information

A read-across was made from source substance 3 (C16-18 IOS-Na C18-rich), Sulfonic Acids, C16-18-alkane hydroxyl and C16-18-sec-alkane hydroxyl and C16-18-alkene and C16-18-sec-alkene, sodium salts (abbreviation C16-18 IOS-Na C18-rich).

The read-across is supported with ECOSAR QSAR calculations for the two main structures of source and target substance (HO-C18H36-SO3Na and HO-C16H32-SO3Na). The calculations showing for the C18-component lower resp. even effect concentrations compared to the C-18-component. The conclusion for this is, that making read-across from the source substance (with a higher amount of the C18-component compared to the target substance) is a worst case approach.

Read-across is based on a Klimisch 1 study according to guideline OECD 202 with analytical monitoring resulting in a 48h-EC50 of 1.1 mg a.i./L.

The read-across is supported with a published valid experimental test with Sodium C14-16 alpha olefin sulfonate (CAS 68439-57-6) for the vertebrate species Ceriodaphnia dubia Richard. The test was made under conditions comparable to guideline OECD202. The 48h-EC50 is 4.53mg/L.
The numerical value is higher than the result of the read-across approach and thus supports the conclusion that the read-across approach represents a worst-case assumption

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

1.1 mg/L