Sulfuric acid, mono-C8-18-alkyl esters, magnesium salts, compds. with triethanolamine

Adsorption / desorption

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

adsorption / desorption, other

Remarks:

adsorption

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Qualifier:

no guideline followed

Principles of method if other than guideline:

Sorption experiments with sediment from artificial pond (organic carbon content 22%). Determination of alkyl sulfates using methylene blue assay.

GLP compliance:

no

Type of method:

HPLC estimation method

Media:

sediment

Test temperature:

25 °C

Analytical monitoring:

yes

Details on matrix:

- Details on collection (e.g. location, depth, contamination history, procedure): obtained from artificial pond through which part of a stream at the Institute of Freshwater Ecology, River Laboratory site may be directed, collection on 20 Nov 1988 and 23 March 1989; using fine mesh sieve (2 mm), dried at 85 °C and passed successively through sieves of 2, 0.319 and 0.125 mm size, organic carbon removed, then treatment of 250 g sediment with 500 mL 0.1 M NaOH for 24 hours, filtration of supernatant and subsequent acidification with concentrated HCl to final pH of 1.5
- Textural classification (i.e. % sand/silt/clay): clay, particles <0.125 mm, humic fraction used
- Organic carbon (%): 22.2% by weight, however removed by pretreatment with hydrogen peroxide, resulting in humic fraction
- Specific surface area: 8.24 m2/g with BET c constant of 56.0
- Mineral composition: quartz and calcite, some feldspars and mica

Details on test conditions:

TEST SYSTEM
- Type, size and further details on reaction vessel: Adsorption apparatus: solution in contact with suspended adsorbent was circulated via syringe pump (through 0.1 µm cellulose nitrate filter) via valve K, operated by stepper motor, PTFE tubing was flushed thoroughly before sample was directed to fraction collector J; 200 mL 10 mM NaHCO3 was weighed into the adsorption cell and allowed to come to thermal equilibrium with CO2/N2 mixture to give a pH of 7.6 ± 0.02; Adsorbent was added to the cell and left for 1 h before a sample was removed for analysis; stock solution of AS added from autoburette and after 20 min a sample was removed for analysis. Procedure was repeated with successive additions of AS. Isotherm computed from data retrieved from the autoburette and the surfactant.

Key result

Type:

Koc

Value:

> 75 - < 100

Temp.:

25 °C

% Org. carbon:

22

Key result

Type:

log Koc

Value:

> 1.88 - < 2

Temp.:

25 °C

% Org. carbon:

22

Adsorption constants for 2 separate batches of sediment were estimated from adsorption isotherms:
Sediment S1:  16.7 +- 1.9 dm3/kg
Sediment S2:  22.3 +- 2.9 dm3/kg

Validity criteria fulfilled:

not applicable

Reference 2

Endpoint:

adsorption / desorption, other

Remarks:

adsorption

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Recalculation based on the available experimental data for read-across substances.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Experimental data for pure homologues: C8, C10, C12 and C14 AS homologues with sediment from artificial pond (organic carbon content 22%). Determination of alkyl sulfates using methylene blue assay. Recalculation was made for C16AS Na.

GLP compliance:

no

Type of method:

other: recalculation based on experimental data for read-across substances

Media:

sediment

Key result

Type:

log Koc

Value:

3.515

Temp.:

25 °C

% Org. carbon:

22

No experimental data on adsorption coefficient of C16AS Na (CAS 1120-01-0) are available. Nevertheless, experimental values of adsorption coefficient are presented in the publication of Marchesi et al. (1991) for pure AS homologues: C8 (CAS 142-31-4), C10 (CAS 142-87-0), C12 (CAS 151-21-3) and C14 (CAS 1191-50-0). The determined Koc values are:

- for C8AS Na (CAS 142-31-4) between 75 and 100 which corresponds to log Koc values in the range of 1.88 and 2.0.

- for C10AS Na (CAS 142-87-0) between 122 and 178 which corresponds to log Koc values in the range of 2.09 and 2.25.

- for C12AS Na (CAS 151-21-3) between 316 and 446 which corresponds to log Koc values in the range of 2.5 and 2.65.

- for C14AS Na (CAS 1191-50-0) between 1337 and 1567 which corresponds to log Koc values in the range of 3.13 and 3.19.

Adsorption coefficient for the pure homologue C16AS Na (CAS 1120-01-0) was extrapolated based on the above experimental data. The log Koc value was taken from the regression line constructed based on C8 – C14 data: y = 0.1985x + 0.339 (R2=0.974 proving a very good fit).

The results show that log Koc for C16 homologue equals 3.515.

The extrapolation based on experimental data was chosen as the most reliable method of determining Koc values for C16AS Na. Other calculation methods of adsorption coefficient e.g. EPISUITE are not reliable. According to OECD SIDS Initial Assessment Report for Alkyl Sulfates (2007) when comparing EPISUITE calculations and experimental derived Koc, the calculated values are significantly higher. This happens because surfactancy and dissociation are not taken into account in the EPI Suite estimations. Therefore calculated Koc values should not be used for the exposure assessment since they are not reliable.

The log Koc value of C16AS Na (CAS 1120-01-0) is 3.515.

Validity criteria fulfilled:

not applicable

Reference 3

Endpoint:

adsorption / desorption, other

Remarks:

adsorption

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Recalculation based on the available experimental data for read-across substances.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Experimental data for pure homologues: C8, C10, C12 and C14 AS homologues with sediment from artificial pond (organic carbon content 22%). Determination of alkyl sulfates using methylene blue assay. Recalculation was made for C18 AS Na.

GLP compliance:

no

Type of method:

other: recalculation based on experimental data for read-across substances

Media:

sediment

Key result

Type:

log Koc

Value:

3.912

Temp.:

25 °C

% Org. carbon:

22

No experimental data on adsorption coefficient of C18AS Na (CAS 1120-04-3) are available. Nevertheless, experimental values of adsorption coefficient are presented in the publication of Marchesi et al. (1991) for pure AS homologues: C8AS Na (CAS 142-31-4), C10AS Na (CAS 142-87-0), C12 (CAS 151-21-3) and C14AS Na (CAS 1191-50-0). The determined Koc values are:

- for C8AS Na (CAS 142-31-4) between 75 and 100 which corresponds to log Koc values in the range of 1.88 and 2.0.

- for C10AS Na (CAS 142-87-0) between 122 and 178 which corresponds to log Koc values in the range of 2.09 and 2.25.

- for C12AS Na (CAS 151-21-3) between 316 and 446 which corresponds to log Koc values in the range of 2.5 and 2.65.

- for C14AS Na (CAS 1191-50-0) between 1337 and 1567 which corresponds to log Koc values in the range of 3.13 and 3.19.

Adsorption coefficient for pure homologue C18AS Na (CAS 1120-04-3) was extrapolated based on the above experimental data. The log Koc value was taken from the regression line constructed based on C8 – C14 data: y = 0.1985x + 0.339 (R2=0.974 proving a very good fit).

The results show that log Koc for C18 homologue equals 3.912.

The extrapolation based on experimental data was chosen as the most reliable method of determining Koc values for the C18 homologue. Other calculation methods of adsorption coefficient e.g. EPISUITE are not reliable. According to OECD SIDS Initial Assessment Report for Alkyl Sulfates (2007) when comparing EPISUITE calculations and experimental derived Koc, the calculated values are significantly higher. This happens because surfactancy and dissociation are not taken into account in the EPI Suite estimations. Therefore calculated Koc values should not be used for the exposure assessment since they are not reliable.

The log Koc value of C18AS Na (CAS 1120-04-3) is 3.912.

Validity criteria fulfilled:

not applicable

Reference 4

Endpoint:

adsorption / desorption, other

Remarks:

adsorption

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Qualifier:

no guideline followed

Principles of method if other than guideline:

Sorption experiments with sediment from artificial pond (organic carbon content 22%). Determination of alkyl sulfates using methylene blue assay.

GLP compliance:

no

Type of method:

HPLC estimation method

Media:

sediment

Radiolabelling:

no

Test temperature:

25 °C

Details on study design: HPLC method:

IDENTIFICATION AND QUANTIFICATION OF TEST SUBSTANCE/PRODUCT
- Separation method (e.g. HPLC, GC): Gas chromatography (Perkin-Elmer-F33-Chromatograph with FID)
- Conditions (column, mobile phase, etc.): Glass column (1.5 m x 5 mm), packed with 15% (w/w) ethylene glycol succinate silicone (EGSS-X) on 80-100 mesh Chromosorb
- Detection method (e.g. ECD, UV, MS, ICP-AES, ICP-MS): Injector and detector temperatures 225 °C, carrier gas N2 at a pressure of 280 kN/m2

Analytical monitoring:

yes

Details on matrix:

- Details on collection (e.g. location, depth, contamination history, procedure: obtained from artificial pond through which part of a stream at the Institute of Freshwater Ecology, River Laboratory site may be directed, collection on 20 Nov 1988 and 23 March 1989; using fine mesh sieve (2 mm), dried at 85 °C and passed successively through sieves of 2, 0.319 and 0.125 mm size, organic carbon removed, then treatment of 250 g sediment with 500 mL 0.1M NaOH for 24 hours, filtration of supernatant and subsequent acidification with concentrated HCl to final pH of 1.5
- Textural classification (i.e. %sand/silt/clay): clay, particles <0.125 mm, humic fraction used
- Organic carbon (%): 22.2% by weight, however removed by pretreatment with hydrogen peroxide, resulting in humic fraction
- Specific surface area: 8.24 m2/g with BET c constant of 56.0
- Mineral composition: quartz and calcite, some feldspars and mica

Details on test conditions:

TEST SYSTEM
- Type, size and further details on reaction vessel: Adsorption apparatus: solution in contact with suspended adsorbent was circulated via syringe pump (through 0.1 µm cellulose nitrate filter) via valve K, operated by stepper motor, PTFE tubing was flushed thoroughly before sample was directed to fraction collector J; 200 mL 10 mM NaHCO3 was weighed into the adsorption cell and allowed to come to thermal equilibrium with CO2/N2 mixture to give a pH of 7.6 ± 0.02; Adsorbent was added to the cell and left for 1 h before a sample was removed for analysis; stock solution of AS added from autoburette and after 20 min a sample was removed for analysis; Procedure was repeated with successive additions of AS. Isotherm computed from data retrieved from the autoburette and the surfactant.

Key result

Type:

Koc

Value:

> 1 337 - < 1 567

Temp.:

25 °C

Key result

Type:

log Koc

Value:

> 3.13 - < 3.19

Temp.:

25 °C

Experimentally derived sediment-water partition coefficients (kd) and sorption coefficients for alkyl sulfates on sediment (Marchesi et al. 1991):

CAS	Chain-length	Kd	Koc
142-31-4	C8	16.7-22.3	75-101
1072-15-7	C9	26.1-32.6	118-147
142-87-0	C10	27.1-39.5	122-178
Not available	C11	76.7-81.7	346-368
151-21-3	C12	70.2-99.1	316-446
3026-63-9	C13	135.0-142.7	608-642
1191-50-0	C14	296.7-347.9	1337-1567

 

Reference 5

Endpoint:

adsorption / desorption, other

Remarks:

adsorption

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Qualifier:

no guideline followed

Principles of method if other than guideline:

Sorption experiments with sediment from artificial pond (organic carbon content 22%). Determination of alkyl sulfates using methylene blue assay.

GLP compliance:

no

Type of method:

HPLC estimation method

Media:

sediment

Radiolabelling:

no

Test temperature:

25 °C

Details on study design: HPLC method:

IDENTIFICATION AND QUANTIFICATION OF TEST SUBSTANCE/PRODUCT
- Separation method (e.g. HPLC, GC): Gas chromatography (Perkin-Elmer-F33-Chromatograph with FID)
- Conditions (column, mobile phase, etc.): Glass column (1.5 m x 5 mm), packed with 15% (w/w) ethylene glycol succinate silicone (EGSS-X) on 80-100 mesh Chromosorb
- Detection method (e.g. ECD, UV, MS, ICP-AES, ICP-MS): Injector and detector temperatures 225 °C, carrier gas N2 at a pressure of 280 kN/m2

Analytical monitoring:

yes

Details on matrix:

- Details on collection (e.g. location, depth, contamination history, procedure: obtained from artificial pond through which part of a stream at the Institute of Freshwater Ecology, River Laboratory site may be directed, collection on 20 Nov 1988 and 23 March 1989; using fine mesh sieve (2 mm), dried at 85 °C and passed successively through sieves of 2, 0.319 and 0.125 mm size, organic carbon removed, then treatment of 250 g sediment with 500 mL 0.1M NaOH for 24 hours, filtration of supernatant and subsequent acidification with concentrated HCl to final pH of 1.5
- Textural classification (i.e. %sand/silt/clay): clay, particles <0.125 mm, humic fraction used
- Organic carbon (%): 22.2% by weight, however removed by pretreatment with hydrogen peroxide, resulting in humic fraction
- Specific surface area: 8.24 m2/g with BET c constant of 56.0
- Mineral composition: quartz and calcite, some feldspars and mica

Details on test conditions:

TEST SYSTEM
- Type, size and further details on reaction vessel: Adsorption apparatus: solution in contact with suspended adsorbent was circulated via syringe pump (through 0.1 µm cellulose nitrate filter) via valve K, operated by stepper motor, PTFE tubing was flushed thoroughly before sample was directed to fraction collector J; 200 mL 10 mM NaHCO3 was weighed into the adsorption cell and allowed to come to thermal equilibrium with CO2/N2 mixture to give a pH of 7.6 ± 0.02; Adsorbent was added to the cell and left for 1 h before a sample was removed for analysis; stock solution of AS added from autoburette and after 20 min a sample was removed for analysis; Procedure was repeated with successive additions of AS. Isotherm computed from data retrieved from the autoburette and the surfactant.

Key result

Type:

Koc

Value:

> 122 - < 178

Temp.:

25 °C

% Org. carbon:

22

Key result

Type:

log Koc

Value:

> 2.09 - < 2.25

Temp.:

25 °C

% Org. carbon:

22

Experimentally derived sediment-water partition coefficients (kd) and sorption coefficients for alkyl sulfates on sediment (Marchesi et al. 1991):

CAS	Chain-length	Kd	Koc
142-31-4	C8	16.7-22.3	75-101
1072-15-7	C9	26.1-32.6	118-147
142-87-0	C10	27.1-39.5	122-178
Not available	C11	76.7-81.7	346-368
151-21-3	C12	70.2-99.1	316-446
3026-63-9	C13	135.0-142.7	608-642
1191-50-0	C14	296.7-347.9	1337-1567

 

Reference 6

Endpoint:

adsorption / desorption, other

Remarks:

adsorption

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Qualifier:

no guideline followed

Principles of method if other than guideline:

Sorption experiments with sediment from artificial pond (organic carbon content 22%). Determination of alkyl sulfates using methylene blue assay.

GLP compliance:

no

Type of method:

HPLC estimation method

Media:

sediment

Radiolabelling:

no

Test temperature:

25 °C

Analytical monitoring:

yes

Details on matrix:

- Details on collection (e.g. location, depth, contamination history, procedure: obtained from artificial pond through which part of a stream at the Institute of Freshwater Ecology, River Laboratory site may be directed, collection on 20 Nov 1988 and 23 March 1989; using fine mesh sieve (2mm), dried at 85°C and passed successively through sieves of 2, 0.319 and 0.125 mm size, organic carbon removed, then treatment of 250 g sediment with 500 mL 0.1M NaOH for 24 hours, filtration of supernatant and subsequent acidification with concentrated HCl to final pH of 1.5
- Textural classification (i.e. %sand/silt/clay): clay, particles <0.125mm, humic fraction used
- Organic carbon (%): 22.2% by weight, however removed by pretreatment with hydrogen peroxide, resulting in humic fraction
- Specific surface area: 8.24 m2/g with BET c constant of 56.0
- Mineral composition: quartz and calcite, some feldspars and mica

Details on test conditions:

TEST SYSTEM
- Type, size and further details on reaction vessel: Adsorption apparatus: solution in contact with suspended adsorbent was circulated via syringe pump (through 0.1 µm cellulose nitrate filter) via valve K, operated by stepper motor, PTFE tubing was flushed thoroughly before sample was directed to fraction collector J; 200 mL 10 mM NaHCO3 was weighed into the adsorption cell and allowed to come to thermal equilibrium with CO2/N2 mixture to give a pH of 7.6 ± 0.02; Adsorbent was added to the cell and left for 1 h before a sample was removed for analysis; stock solution of AS added from autoburette and after 20 min a sample was removed for analysis; Procedure was repeated with successive additions of AS. Isotherm computed from data retrieved from the autoburette and the surfactant.

Key result

Type:

Koc

Value:

> 316 - < 446

Temp.:

25 °C

% Org. carbon:

22

Key result

Type:

log Koc

Value:

> 2.49 - < 2.64

Temp.:

25 °C

% Org. carbon:

22

Details on results (HPLC method):

- Average retention data for test substance: Rapid uptake within the first 20 minutes following the SDS addition indicated a fast adsorption process; after this period, a slow disappearance of SDS from the medium occurred over at least 9 hours. After 1 hour, the linear uptake rate was 0.18 µmol/g/h. A repeat of the experiment in the presence of 0.1% (w/v) sodium azide to inhibit microbial respiration produced similar results with an uptake rate of 0.23 µmol/g/h.

Adsorption and desorption constants:

ki (in dm3/kg):
C12 Sediment 1: ki = 70.2 ± 9.2 (least square line from the isotherms)
C12 Sediment 2: ki = 99.1 ± 12.3 (least square line from the isotherms)

Experimentally derived sediment-water partition coefficients (kd) and sorption coefficients for alkyl sulfates on sediment (Marchesi et al. 1991):

CAS	Chain-length	Kd	Koc
142-31-4	C8	16.7-22.3	75-101
1072-15-7	C9	26.1-32.6	118-147
142-87-0	C10	27.1-39.5	122-178
Not available	C11	76.7-81.7	346-368
151-21-3	C12	70.2-99.1	316-446
3026-63-9	C13	135.0-142.7	608-642
1191-50-0	C14	296.7-347.9	1337-1567

Reference 7

Endpoint:

adsorption / desorption, other

Remarks:

adsorption

Type of information:

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

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Justification for type of information:

Read across justification is attached in chapter 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Key result

Type:

log Koc

Value:

>= 1.88 - <= 2 dimensionless

Temp.:

25 °C

Remarks on result:

other: CAS 142-31-4 (C8)

Key result

Type:

log Koc

Value:

>= 2.09 - <= 2.25 dimensionless

Temp.:

25 °C

Remarks on result:

other: CAS 142-87-0 (C10)

Key result

Type:

log Koc

Value:

>= 2.49 - <= 2.64 dimensionless

Temp.:

25 °C

Remarks on result:

other: CAS 151-21-3 (C12)

Key result

Type:

log Koc

Value:

>= 3.13 - <= 3.19 dimensionless

Temp.:

25 °C

Remarks on result:

other: CAS 1191-50-0 (C14)

Key result

Type:

log Koc

Value:

3.515 dimensionless

Temp.:

25 °C

Remarks on result:

other: CAS 1120-01-0 (C16)

Key result

Type:

log Koc

Value:

3.912 dimensionless

Temp.:

25 °C

Remarks on result:

other: CAS 1120-04-3 (C18)

Description of key information

log Koc between 1.88 and 3.9

Key value for chemical safety assessment

Koc at 20 °C:

8 166

Additional information

Since no reliable adsorption tests are available for C8-18AS Mg & TEA (CAS 85586-38-5), in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 read-across to constituents of the target substance was performed. Read-across data available for the pure AS homologues: C8AS Na (CAS 142-31-4), C10AS Na (CAS 142-87-0), C12AS Na (CAS 151-21-3), C14AS Na (CAS 1191-50-0), C16AS Na (CAS 1120-01-0) and C18AS Na (CAS 1120-04-3) were used. In the publication by Marchesi et al. (1991), the experimental sediment sorption data for several alkyl sulfates with different carbon chain lengths are presented. The Koc values for the longer homologues: C16AS Na (CAS 1120-01-0) and C18AS Na (CAS 1120-04-3) were extrapolated from the available data on C8-14 alkyl sulfates.

The determined Koc values are:

- for C8AS Na (CAS 142-31-4) between 75 and 100 which corresponds to log Koc values in the range of 1.88 and 2.0.

- for C10AS Na (CAS 142-87-0) between 122 and 178 which corresponds to log Koc values in the range of 2.09 and 2.25.

- for C12AS Na (CAS 151-21-3) between 316 and 446 which corresponds to log Koc values in the range of 2.5 and 2.65.

- for C14AS Na (CAS 1191-50-0) between 1337 and 1567 which corresponds to log Koc values in the range of 3.13 and 3.19.

- for C16AS Na (CAS 1120-01-0) the extrapolated value of Koc equals 3273 which corresponds to log Koc 3.515.

- for C18AS Na (CAS 1120-04-3) the extrapolated value of Koc equals 8166 which corresponds to log Koc 3.912.

Due to structural and property similarities with the tested category members these results apply also to C8-18AS Mg & TEA (CAS 85586-38-5). The Koc range is between 75 and 8166 corresponding to the log Koc range between 1.88 and 3.9. Adsorption of the substance to soil or sediment is therefore assumed to be low to moderate. For the PNEC sediment and soil derivation according to the equilibrium partitioning method (EPM), the lower boundary of the range (Koc = 75) was taken into account, since this value represents the worst case scenario for the chemical safety assessment.

[LogKoc: 3.912]