Sodium benzenesulphinate

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:

The supporting QMRF report has been attached

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Principles of method if other than guideline:

Prediction is done using OECD QSAR Toolbox version 3.3 with logKow as the primary descriptor.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material: sodium benzenesulfinate
- Molecular formula (if other than submission substance): C6H6O2S.Na
- Molecular weight (if other than submission substance): 164.16 g/mol
- Smiles notation (if other than submission substance): c1(ccccc1)S(=O)[O-].[Na+]
- InChI: 1S/C6H6O2S.Na/c7-9(8)6-4-2-1-3-5-6;/h1-5H,(H,7,8);/q;+1/p-1
- Substance type: Organic
- Physical state: Solid

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

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

105.253 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

growth rate

The prediction was based on dataset comprised from the following descriptors: EC50
Estimation method: Takes average value from the 5 nearest neighbours
Domain  logical expression:Result: In Domain

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

Domain logical expression index: "a"

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

Domain logical expression index: "b"

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

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Aromatic Carbon [C] OR Miscellaneous sulfide (=S) or oxide (=O) OR Olefinic carbon [=CH- or =C<] OR Suflur {v+4} or {v+6} by Organic functional groups (US EPA) ONLY

Domain logical expression index: "d"

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

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as No alert found by Protein binding by OASIS v1.3

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Michael Addition OR Michael Addition >> Polarised Alkenes OR Michael Addition >> Polarised Alkenes >> Polarised Alkene - alkenyl pyridines, pyrazines, pyrimidines or triazines  by Protein binding by OASIS v1.3

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Class 5 (Not possible to classify according to these rules) by Acute aquatic toxicity classification by Verhaar (Modified) 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 No alert found by Carcinogenicity (genotox and nongenotox) alerts by ISS

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as alpha,beta-unsaturated carbonyls (Genotox) OR Metals, oxidative stress (Nongenotox) OR Primary aromatic amine,hydroxyl amine and its derived esters (Genotox) OR Structural alert for genotoxic carcinogenicity OR Structural alert for nongenotoxic carcinogenicity OR Structural alerts for both genotoxic and nongenotoxic carcinogenicity by Carcinogenicity (genotox and nongenotox) alerts by ISS

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Does NOT Biodegrade Fast by Biodeg probability (Biowin 6) ONLY

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as Not categorized by US-EPA New Chemical Categories

Domain logical expression index: "m"

Referential boundary: The target chemical should be classified as Aluminum Compounds OR Lanthanides or Rare Earth Metals OR Nickel Compounds OR Soluble complexes of Zinc OR Vinyl Sulfones OR Zirconium Compounds by US-EPA New Chemical Categories

Domain logical expression index: "n"

Parametric boundary:The target chemical should have a value of log Kow which is >= -5.85

Domain logical expression index: "o"

Parametric boundary:The target chemical should have a value of log Kow which is <= 0.0859

Validity criteria fulfilled:

not specified

Conclusions:

The median Effective concentration (EC50) value for sodium benzenesulfinate on Pseudokirchneriella subcapitata in a 72 hour study was estimated to be 105.25 mg/L on the basis of effects on growth rate.

Executive summary:

Using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the five closest read across substances, the short term toxicity on aquatic algae and cyanobacteria was predicted for target substance sodium benzenesulfinate (CAS no. 873 -55 -2). EC50 value was estimated to be 105.25 mg/l for Pseudokirchneriella subcapitata for 72 h duration. Based on this value it can be concluded that the substance sodium benzenesulfinate is considered to be non-toxic to aquatic environment and can be considered to be not classified as per the CLP classification criteria.

Description of key information

Using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the five closest read across substances, the short term toxicity on aquatic algae and cyanobacteria was predicted for target substance sodium benzenesulfinate (CAS no. 873 -55 -2). EC50 value was estimated to be 105.25 mg/l for Pseudokirchneriella subcapitata for 72 h duration. Based on this value it can be concluded that the substance sodium benzenesulfinate is considered to be non-toxic to aquatic environment and can be considered to be not classified as per the CLP classification criteria.

Key value for chemical safety assessment

EC50 for freshwater algae:

105.25 mg/L

Additional information

Various predicted data for the target chemical sodium benzenesulfinate(CAS No. 873-55-2) and various weight of evidence study for its read across substance were reviewed to summarize the following information:

Short term toxicity on aquatic algae and cyanobacteria of target chemical sodium benzenesulfinate(CAS No. 873-55-2) is predicted using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the five closest read across substances (2017). EC50 value was estimated to be 105.25 mg/l for Pseudokirchneriella subcapitata for 72 h duration. Based on this value it can be concluded that the substance sodium benzenesulfinate is considered to be non-toxic to aquatic environment and can be considered to be not classified as per the CLP classification criteria.

 

In a weight of evidence study from authoritative database (ECOTOX, 2017) of the read across chemical Benzenesulphonic acid (CAS no. 98 -11 -3),short term toxicity to Navicula seminulum (Pennate diatom) study was carried out for 96 hrs. The study was based on the effects of the read across compound Benzenesulphonic acid on Navicula seminulum in a static fresh water system at a temperature of 28°C and hardness of 77 mg/l as CaCO3 respectively. Based on effect on population of the test organism Navicula seminulum, the 96 hr EC50 value was determined to be 19500 mg/l, respectively. Thus, based on the EC50 value, it can be concluded that the substance Benzenesulphonic acid can be considered as non-toxic to aquatic organisms and thus can be considered to be not classified as per the CLP classification criteria.

 

Another short term toxicity to Selenastrum capricornutum (green algae) study was carried out for 72 hrs (HPVIS, 2016). The study was performed according to OECD Guideline 201 (Alga, Growth Inhibition Test) and was based on the effects of the read across compound Benzenesulphonic acid (CAS no. 98 -11 -3) on Selenastrum capricornutum in a static fresh water system under a continuous illumination with a light intensity within the range of 73 to 101 uE/m2/s, at a temperature of 22.5 - 23°C, pH of 8.3 ± 0.2 and hardness of 24 mg/l as CaCO3 respectively. Pretreatment was given to the test organism for 3 days under test conditions. Test chemical concentration used for the study was 0, 4.6, 10, 22, 46, 100 and 220 mg/L (nominal concentration) and 0 (not detected), 4.3, 10.1, 21.9, 44.8, 101, 224 and 233 mg/l (measured concentration), respectively. A stock solution of 220 mg/L was prepared in test medium, applying 56 minutes of magnetic stirring. Lower test concentrations were prepared by subsequent dilutions of the stock in test medium. Analytical determinations were carried out using HPLC (RP, UV detection at 263 nm). Potassium dichromate was used as a reference substance in the study. All tests were performed in triplicates except the blank control was performed in 6 replicates. Inhibition of cell growth and reduction of growth rate was measured at 0 hr and 72 hr. Based on effect on cell growth inhibition and growth rate reduction of the test organism Selenastrum capricornutum, the 72 hr NOEC value was determined to be 46 mg/l and on the basis of effect on cell growth inhibition and growth rate reduction, the 72 hr EC50 value was determined to be 70 and 73 mg/l, respectively. Thus, based on the EC50 value, it can be concluded that the substance Benzenesulphonic acid can be considered as toxic to aquatic organisms. Since the chemical is readily biodegradable in nature, chemical Benzenesulphonic acid can be considered as non-toxic to aquatic organisms and thus can be considered to be not classified as per the CLP classification criteria.

 

Thus, based on the overall reported results for target chemicalsodium benzenesulfinate(OECD QSAR toolbox version 3.3, 2017) and for its read across substance (from authoritative database ECOTOX, 2017 and secondary source HPVIS, 2016), it can be concluded that the test substancesodium benzenesulfinatecan be considered asnon-toxic to aquatic environment and can be considered to be not classified as per the CLP classification criteria.