Ethylbenzenesulphonic acid

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

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 limited documentation / justification

Justification for type of information:

Data is from OECD QSAR toolbox version 3.3 and the QMRF report has been attached.

Qualifier:

according to guideline

Guideline:

other: Estimated data

Principles of method if other than guideline:

Prediction was done using the OECD QSAR toolbox version 3.3.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name: Ethylbenzenesulphonic acid
- Molecular Weight: 186.23 g/mole
- Molecular Formula: C8H10O3S
- SMILES:CCc1ccccc1S(O)(=O)=O
- InChI:1S/C8H10O3S/c1-2-7-3-5-8(6-4-7)12(9,10)11/h3-6H,2H2,1H3,(H,9,10,11)

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Test type:

static

Water media type:

freshwater

Total exposure duration:

72 h

Test temperature:

22.0°C - 22.5°C

pH:

8-8.1

Nominal and measured concentrations:

Estimated

Reference substance (positive control):

not specified

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

193.676 mg/L

Nominal / measured:

estimated

Conc. based on:

not specified

Basis for effect:

growth rate

Remarks on result:

other: Other details not known

Details on results:

The EC50 was 193.6764 mg/l.

The prediction was based on dataset comprised from the following descriptors: EC50
Estimation method: Takes average value from the 11 nearest neighbours
Domain  logical expression:Result: In Domain

(((((("a" or "b" or "c" or "d" or "e" or "f" )  and "g" )  and "h" )  and ("i" and ( not "j") )  )  and ("k" and ( not "l") )  )  and ("m" and "n" )  )

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Linear alkylbenzene sulfonates by OECD HPV Chemical Categories

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as Anionic Surfactants by US-EPA New Chemical Categories

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Aromatic compound OR Sulfonic acid OR Sulfonic acid derivative by Organic functional groups, Norbert Haider (checkmol) ONLY

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Aliphatic Carbon [CH] OR Aliphatic Carbon [-CH2-] OR Aliphatic Carbon [-CH3] OR Aromatic Carbon [C] OR Hydroxy, sulfur attach [-OH] OR Miscellaneous sulfide (=S) or oxide (=O) OR Olefinic carbon [=CH- or =C<] OR Suflur {v+4} or {v+6} OR Sulfinic acid [-S(=O)OH] OR Sulfonate, aromatic attach [-SO2-O] by Organic functional groups (US EPA) ONLY

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Alkyl arenes OR Overlapping groups OR Sulfonic acid by Organic Functional groups (nested) ONLY

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Alkyl arenes OR Aryl OR Sulfonic acid by Organic Functional groups ONLY

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Not Related to an Existing ECOSAR Class by Aquatic toxicity classification by ECOSAR ONLY

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Very fast by Bioaccumulation - metabolism half-lives ONLY

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Non-Metals by Groups of elements

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Rare Earth by Groups of elements

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Non-Metals by Groups of elements

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as Halogens by Groups of elements

Domain logical expression index: "m"

Parametric boundary:The target chemical should have a value of log Kow which is >= -4.34

Domain logical expression index: "n"

Parametric boundary:The target chemical should have a value of log Kow which is <= 2.24

Validity criteria fulfilled:

not specified

Conclusions:

Based on the growth rate inhibition of algae the EC50 value was estimated to be 193.676 mg/l when Ethylbenzenesulphonic acid exposed to Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) for 72hrs.

Executive summary:

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the ten closest read across substances, toxicity on Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) was predicted for Ethylbenzenesulphonic acid (57352-34-8). Based on the growth rate inhibition of algae the EC50 value was estimated to be 193.676 mg/l when Ethylbenzenesulphonic acid exposed to Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) for 72hrs.

Based on this value it can be concluded that the substance Ethylbenzenesulphonic acidis considered to not toxic to aquatic environment as per the criteria mentioned in CLP regulation.   

 

Description of key information

Using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the ten closest read across substances, toxicity on Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) was predicted for Ethylbenzenesulphonic acid (57352-34-8). Based on the growth rate inhibition of algae the EC50 value was estimated to be 193.676 mg/l when Ethylbenzenesulphonic acid exposed to Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) for 72hrs. Based on this value it can be concluded that the substance Ethylbenzenesulphonic acidis considered to not toxic to aquatic environment as per the criteria mentioned in CLP regulation.   

 

Key value for chemical safety assessment

EC50 for freshwater algae:

193.676 mg/L

Additional information

Based on the various experimental data and prediction data for the target chemical study have been reviewed to determine the toxic nature of Ethylbenzenesulphonic acid (57352-34-8) on the growth of aquatic algae. The studies are as mentioned below:

The first predicted study for the target chemical Ethylbenzenesulphonic acid (57352-34-8) from QSAR toolbox 2017, using based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the ten closest read across substances, toxicity on Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) was predicted for Ethylbenzenesulphonic acid (57352-34-8). Based on the growth rate inhibition of algae the EC50 value was estimated to be 193.676 mg/l when Ethylbenzenesulphonic acid exposed to Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) for 72hrs. Based on this value it can be concluded that the substance Ethylbenzenesulphonic acid is considered to not toxic to aquatic environment as per the criteria mentioned in CLP regulation.   

 

In second predicted study for the target chemical Ethylbenzenesulphonic acid (57352-34-8) from Danish QSAR, 2017 was used based on the prediction done using the three different models i.e, Battery, Leadscope and SciQSAR used within Danish QSAR database, the short term toxicity on green algae was predicted for test substance  Ethylbenzenesulphonic acid (57352 -34 -8). The average EC50 value was given by the third model i.e, Battery model. On the basis of effects observed in a static freshwater system, the effect concentration EC50 value for the substance Ethylbenzenesulphonic acid is estimated to be 212.0419 mg/l for Pseudokirchneriella subcapitata during 72 hr exposure duration. Thus, on the basis of EC50 value, it can be concluded that the test chemical Ethylbenzenesulphonic acid can be considered as non-toxic to green algae at environmentally relevant concentrations and can be considered not-classified as per the CLP classification criteria.

 

Experimental study for the read across chemical 4-amino-m-toluenesulfonic acid (98-33-9) from ABITEC report, 2017 was studied. Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance 4-amino-3- methylbenzenesulfonic acid according to OECD Guideline 201. The test substance was dissolved in OECD growth medium and tested at the concentrations 0, 0, 30, 45, 67, 100, 150 mg/L. Effects on the growth rate of the organism were studied. The median effective concentration (EC50) for the test substance 4-amino-3- methylbenzene- sulfonic acid, in Desmodesmus subspicatus was determined to be 110.6 mg/L. This value indicates that the substance is likely to be non-hazardous to aquatic algae and cannot be classified as per the CLP criteria.

 

Similarly in the fourth weight of evidence study for the structurally similar read across chemical 1,3-Phenylenediamine-4-sulfonic (88-63-1 ) from ABITEC lab report 2017. Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance 1,3-Phenylenediamine-4-sulfonic Acid according to OECD Guideline 201. The stock solution 150 mg/l was prepared by dissolving light brown powder in OECD growth medium. The solution was kept in ultrasonic bath for 20 min. Test solutions of required concentration were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Sample tested at the concentrations 0, 0, 30, 45, 67, 100 and 150 mg/L. Test performed by the static system for 72hrs of exposure period. Effects on the growth rate of the organism were studied. The median effective concentration (ErC50) for the test substance 1,3-Phenylenediamine-4-sulfonic Acid, in Desmodesmus subspicatus was determined to be 110 mg/L on the basis of effects on growth rate in a 72 hour study. This value indicates that the substance 1,3-Phenylenediamine-4-sulfonic Acid is likely to be non-hazardous to aquatic algae and cannot be classified as toxic as per the CLP classification criteria. 

 

Similarly in the fifth weight of evidence study for the structurally similar read across chemical (98-37-3) Water Research Pergamon Press, 1968. Short term toxicity to Chlorella pyrenoidosa (green algae) study was carried out for 72 hrs. Emerson strain of bacteria free, experimentally reproducible cultures of Chlorella pyrenoidosa was used as a test organism. The procedure involve the use of test tubes in both the screening and final tests. These test tubes contained 15 ml of inorganic culture medium, a predetermined amount of test chemical and 5 ml of algal culture. The tubes were incubated for 72 hrs and chlorophyll content of the algal suspensions was measured every 24 hrs. For chlorophyll measurement, the chlorophyll pigment was extracted with hot methanol in two separate extractions. An algal suspension, 2.5 ml, was removed from the test tube, centrifuged, washed with distilled water, and recentrifuged in preparation of chlorophyll analysis. After discarding the supernatant, the deposited cell material was coagulated by placing the cells in a boiling water bath for about 40 sec. About 2.5 ml of methanol were used in each extraction. Finally, the chlorophyll solution was diluted to a total volume of 10 ml with an acetone-water mixture (80 per cent by volume). A Beckman Spectrophotometer, Model DB, was used to measure the chlorophyll content according to MACKINv (1941) and ARNON (1949). For this a wavelength of 652 m/z was used because different proportions of chlorophyll a and b least affect the results at this wavelength. Control tubes containing no test chemical was also used in the experiment. Knop's solution, including the Hutner-EDTA microelement addition, was used as the culture medium. pH of culture medium was adjusted to 7.0 using KOH before use. The test organism was maintained under steady-state conditions, provided a chlorophyll content of 38 mg/l. Environmental control was rigidly maintained. The temp of water bath was 25 ± 1°C. The test apparatus consisted of a constant-temperature water bath, a light source containing four 200W fluorescent lamps with attached aluminum reflectors, a gas manifold to supply an air-CO2 mixture to each test tube, and a rack to hold the test tubes. A stream of 5 % CO2 in air gas mixture was supplied to culture medium in order to provide the inorganic carbon source and also to keep the algal ceils in suspension. Based on destruction of chlorophyll of test organism by test chemical Amino-1-phenol-4-sulfonic acid, the LOEC value was determine to be1500 mg/l and as no toxic effect at 1000 mg/l was observed, the NOEC value was determine to be 1000 mg/l. Thus, based on this value, it can be concluded that the substance can be considered as non-toxic to aquatic organisms and thus cannot be classified as hazardous as per the CLP criteria.

 

Based on the predicted data for the target chemical (OECD QSAR, Danish QSAR, 2017) and experimental studies for the read across chemical obtain from various sources (ABITEC report, Water Research Pergamon Press, 1968) toxicity on algae was studied due to the exposure of Ethylbenzenesulphonic acid (57352-34-8), it was concluded that the chemical Ethylbenzenesulphonic acid was consider as nontoxic and can be consider to be not classified as toxic to aquatic invertebrates as per CLP classification criteria.