Sodium phenylacetate

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 QMRF report has been attached.

Qualifier:

according to guideline

Guideline:

other: Predicted data

Principles of method if other than guideline:

Prediction is done using QSAR Toolbox version 3.3 with log kow as the primary discriptors.

GLP compliance:

no

Specific details on test material used for the study:

- Name( IUPAC): sodium 2-phenylacetate
- Name of test material (as cited in study report): Sodium phenylacetate
- Molecular formula C8H8O2.Na
- Molecular weight: 158.1313 g/mol
- Smiles notation : c1(ccccc1)CC(=O)[O-].[Na+]
- InChl: 1S/C8H8O2.Na/c9-8(10)6-7-4-2-1-3-5-7;/h1-5H,6H2,(H,9,10);/q;+1/p-1
- Substance type: Organic
- Physical state: solid

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

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

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

100.88 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: not toxic

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 ( not "h") )  )  and "i" )  and ("j" and ( not "k") )  )  and ("l" and "m" )  )

Domain logical expression index: "a"

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

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as Aryl AND Carboxylic acid by Organic Functional groups (nested)

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Aliphatic Carbon [CH] AND Aliphatic Carbon [-CH2-] AND Aromatic Carbon [C] AND Carbonyl, aliphatic attach [-C(=O)-] AND Miscellaneous sulfide (=S) or oxide (=O) AND Olefinic carbon [=CH- or =C<] by Organic functional groups (US EPA)

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Anion AND Aromatic compound AND Carbonic acid derivative AND Carboxylic acid derivative AND Carboxylic acid salt AND Cation by Organic functional groups, Norbert Haider (checkmol)

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 Acylation OR Acylation >> Direct acylation involving a leaving group OR Acylation >> Direct acylation involving a leaving group >> Azlactones and unsaturated lactone derivatives  OR Acylation >> Direct acylation involving a leaving group >> Carbamates  OR Acylation >> Ester aminolysis OR Acylation >> Ester aminolysis >> Amides OR Acylation >> Ester aminolysis or thiolysis OR Acylation >> Ester aminolysis or thiolysis >> Activated aryl esters  OR Acylation >> Ring opening acylation OR Acylation >> Ring opening acylation >> beta-Lactams  OR Nucleophilic addition OR Nucleophilic addition >> Addition to carbon-hetero double bonds OR Nucleophilic addition >> Addition to carbon-hetero double bonds >> Ketones OR SN2 OR SN2 >> Nucleophilic substitution on benzilyc carbon atom OR SN2 >> Nucleophilic substitution on benzilyc carbon atom >> alpha-Activated benzyls  OR SN2 >> SN2 Reaction at a sp3 carbon atom OR SN2 >> SN2 Reaction at a sp3 carbon atom >> Activated alkyl esters and thioesters  OR SNAr OR SNAr >> Nucleophilic aromatic substitution on activated aryl and heteroaryl compounds OR SNAr >> Nucleophilic aromatic substitution on activated aryl and heteroaryl compounds >> Activated aryl and heteroaryl compounds by Protein binding by OASIS v1.3

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Not known precedent reproductive and developmental toxic potential by DART scheme v.1.0

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Alpha aryloxy substituted acetic acid (9c) OR Known precedent reproductive and developmental toxic potential OR Steroid derivatives OR Steroid nucleus derived ER and AR binders OR Steroid nucleus derived ER and AR binders >> Estradiol-like compounds (2a-1) OR Toluene and small alkyl toluene derivatives (8a) by DART scheme v.1.0

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Bioavailable by Lipinski Rule Oasis ONLY

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Group 1 - Alkali Earth Li,Na,K,Rb,Cs,Fr AND Group 14 - Carbon C AND Group 16 - Oxygen O by Chemical elements

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Group 15 - Nitrogen N by Chemical elements

Domain logical expression index: "l"

Parametric boundary:The target chemical should have a value of log Kow which is >= -2.27

Domain logical expression index: "m"

Parametric boundary:The target chemical should have a value of log Kow which is <= 0.883

Conclusions:

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the closest read across substances, the toxicity on aquatic algae predicted for sodium 2-phenylacetate (CAS: 114-70-5). Effect concentration i.e EC50 value estimated to be 100.88 mg/l for Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) for 72 hrs duration. It can be concluded that the sodium 2-phenylacetate (CAS: 114-70-5) is likely to be not toxic to aquatic algae, hence it can be considered to be “not classified” as per the CLP classification criteria for aquatic environment.

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 closest read across substances, the toxicity on aquatic algae predicted for sodium 2-phenylacetate (CAS: 114-70-5). Effect concentration i.e EC50 value estimated to be 100.88 mg/l for Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) for 72 hrs duration. It can be concluded that the sodium 2-phenylacetate (CAS: 114-70-5) is likely to be not toxic to aquatic algae, hence it can be considered to be “not classified” as per the CLP classification criteria for aquatic environment.

Description of key information

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the closest read across substances, the toxicity on aquatic algae predicted for sodium 2-phenylacetate (CAS: 114-70-5). Effect concentration i.e EC50 value estimated to be 100.88 mg/l for Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) for 72 hrs duration. It can be concluded that the sodium 2-phenylacetate (CAS: 114-70-5) is likely to be not toxic to aquatic algae, hence it can be considered to be “not classified” as per the CLP classification criteria for aquatic environment.

Key value for chemical safety assessment

EC50 for freshwater algae:

100.88 mg/L

Additional information

Following studies includes the predicted data and experimental data of target chemical and stucturally similar read across chemical to conclude the sodium 2-phenylacetate (CAS: 114-70-5) toxicity towards the aquatic algae is summarized as follows:

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the closest read across substances, the toxicity on aquatic algae predicted for sodium 2-phenylacetate (CAS: 114-70-5). Effect concentration i.e EC50 value estimated to be 100.88 mg/l for Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) for 72 hrs duration. It can be concluded that the sodium 2-phenylacetate (CAS: 114-70-5) is likely to be not toxic to aquatic algae,.

Similar predicted data for the target chemical from Danish (Q)SAR Database 2017, indicates that the estimated 96 hrs EC50 value of Sodium phenylacetate on Pseudokirchneriella s. by three different models i.e, Battery, Leadscope and SciQSAR used within Danish QSAR database is 146.92 mg/L. It can be concluded from the estimated value that the Sodium phenylacetate is not toxic to aquatic environment .

Another predicted data from ECOSAR v.1.11 model inidicates that the On the basis of EPI suite, ECOSAR version 1.1, the LC50 value for short term toxicity to aquatic algae was predicted to be 1176.47 mg/l for Sodium phenylacetate in 96 hrs. Based on the EC50 value, it can be concluded that the substance Sodium phenylacetate is not toxic to aquatic environment .

The above predicted data is supported by the exeprimental data of structurally similar read across benzyl butyrate (CAS: 103-37-7) from UERL LAB. suggests that the effect of test item Benzyl butyrate, CAS No. 103-37-7 was studied on the growth of fresh water green algaChlorella vulgaris.The study was conducted following OECD guideline 201- Alga growth inhibition test. The test concentration chosen for the study were 6.25mg/L, 12.5mg/L, 25mg/L, 50 mg/L, 100mg/L and 200mg/L. The test concentrations were prepared using stock solution of the test item using mineral media. The green alga was exposed to the test concentration for a period of 72 hours to observe average specific growth rate and % growth inhibition under the effect of the test item. EC50 calculated graphically through probit analysis was observed to be >200mg/L. Based on this value it can be concluded that the substance Benzyl butyrate is considered to be non-toxic to aquatic environment .

Another experimental study for the read across benzyl acetate (CAS: 140-11-4) from Food and Chemical Toxicology (2015), suggests that

A 72 h algae inhibition test was conducted according to theOECD Guideline 201 (Alga, Growth Inhibition Test).Based on the effect on growth rate of the test organism, the 72 hrs EC50 value was determined to be 110 mg/l, respectively. Thus,based on the EC50 value, it can be concluded that the substance Benzyl acetatecan be considered as non-toxic to aquatic organisms.

Thus based on the effect concentrations which is in the range 100.88 mg/l to1176.47 mg/lgive the conclusion that test substancesodium 2-phenylacetate (CAS: 114-70-5)is likely to be non-toxic to aquatic algae at environmentally relevant concentrations and applying weight of evidence approach it can be considered to be “not classified” as per the CLP classification criteria.