Octyl methacrylate

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Study period:

2017-06-20

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
OECD Toolbox 3.4.0.17

Guideline:

other: REACH Guidance on QSARs R.6

Principles of method if other than guideline:

- Software tool(s) used including version: QSAR-prediction with QSAR Toolbox 3.4.0.17 Database version: 3.8.8/3.1.2

GLP compliance:

no

Specific details on test material used for the study:

SMILES: CCCCCCCCOC(=O)C(C)=C

Test organisms (species):

other:

Details on test organisms:

Species:
Pseudokirchnerella subcapitata (reported as Selenastrum capricornutum)
Selenastrum capricornutum (new name: Pseudokirchnerella subcapitata)
other algae: Selenastrum capricornutum [now called Pseudokirchneriella subcapitata ]
Pseudokirchnerella subcapitata
Desmodesmus subspicatus

Test type:

other: QSAR predicted value

Total exposure duration:

72 h

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.171 mg/L

Nominal / measured:

not specified

Conc. based on:

other: QSAR predicted value

Basis for effect:

growth rate

Remarks on result:

other: QSAR predicted value

QSAR TOOLBOX 3.4.0.17 (database version: 3.8.8/3.1.2) predicted that n-octyl methacrylate has a NOEC of 0.171 mg/L (Algae: Pseudokirchneriella subcapitata; Desmodesmus subspicatus).

Toxicity of the target chemical is predicted from category members using trend analysis based

on 14 values within the range 0.0120 - 400 mg/L from 14 category members. Category members are single

chemicals or mixtures and are selected based on the profile of the target chemical. Only chemicals having

experimental data are listed in the category.

The target chemical FALLS within applicability domain of the prediction.

The data used for calculating the current prediction is taken from 22 experimental values selected from

the following database(s):

1. ECHA CHEM

Validity criteria fulfilled:

yes

Conclusions:

NOEC (72h) algae for n-octyl methacrylate predicted by QSAR TOOLBOX 3.4.0.17 database version: 3.8.8/3.1.2 from category trend analysis of 14 category members is 0.171 mg/L.

Executive summary:

QSAR Toolbox prediction based on trend analysis

Prediction of NOEC Algae (72h) for n-octyl methacrylate

Summary

QSAR TOOLBOX 3.4.0.17 (database version: 3.8.8/3.1.2) predicted that n-octyl methacrylate has a NOEC of 0.171 mg/L (Algae: Pseudokirchneriella subcapitata; Desmodesmus subspicatus).

Toxicity of the target chemical (NOEC = 0.171 mg/L) is predicted from category members using trend analysis based

on 14 values within the range 0.0120 - 400 mg/L from 14 category members. Category members are single

chemicals or mixtures and are selected based on the profile of the target chemical. Only chemicals having

experimental data are listed in the category.

The target chemical FALLS within applicability domain of the prediction.

The data used for calculating the current prediction is taken from 22 experimental values selected from

the following database(s):

1. ECHA CHEM

NOTE: Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

2017-06-20

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
OECD Toolbox 3.4.0.17

Guideline:

other: REACH Guidance on QSARs R.6

Principles of method if other than guideline:

- Software tool(s) used including version: QSAR-prediction with QSAR Toolbox 3.4.0.17 Database version: 3.8.8/3.1.2

GLP compliance:

no

Specific details on test material used for the study:

SMILES: CCCCCCCCOC(=O)C(C)=C

Test organisms (species):

other:

Details on test organisms:

Species:
Pseudokirchnerella subcapitata (reported as Selenastrum capricornutum)
other algae: Selenastrum capricornutum [now called Pseudokirchneriella subcapitata ]
Pseudokirchnerella subcapitata
Selenastrum capricornutum (new name: Pseudokirchnerella subcapitata)
Desmodesmus subspicatus
Scenedesmus subspicatus (new name: Desmodesmus subspicatus)

Test type:

other: QSAR predicted value

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

1.05 mg/L

Nominal / measured:

not specified

Conc. based on:

other: QSAR predicted value

Basis for effect:

growth rate

Remarks on result:

other: QSAR predicted value

QSAR TOOLBOX 3.4.0.17 (database version: 3.8.8/3.1.2) predicted that n-octyl methacrylate has an EC50 = 1.05 mg/L( Daphnia magna).

Toxicity of the target chemical is predicted from category members using trend analysis based

on 12 values within the range 0.0169 - 110 mg/L from 12 category members. Category members are single

chemicals or mixtures and are selected based on the profile of the target chemical. Only chemicals having

experimental data are listed in the category.

The target chemical FALLS within applicability domain of the prediction (see Section 4.3 for details).

The data used for calculating the current prediction is taken from 19 experimental values selected from

the following database(s):

1. ECHA CHEM

Validity criteria fulfilled:

yes

Conclusions:

EC50 (48h) Daphnia magna of n-octyl methacrylate predicted by QSAR TOOLBOX 3.4.0.17 database version: 3.8.8/3.1.2 from category trend analysis of 12 category members is 1.05 mg/l.

The predicted EC50 of 1.05 mg/L for n-octyl methacrylate is slightly above the limit for classification.
Isodecyl methacrylate and 2-ethylhexyl methacrylate are at the upper boundary of the log Kow axis close to the target chemical n-octyl methacrylete. Isodecyl methacrylate, having a higher log Kow value between 6.5 and 7.5, has an EC50 around 0.02 mg/L, but the value is less exact due to the low solubility of the substance. 2-ethylhexyl methacrylate is structural closely related to the target chemical and has a similar log Kow. The EC50 for 2-ethylhexyl methacrylate is in the range between 1 and 10 mg/L and thus underpinning the predicted value for n-octyl methacrylate of 1.05 mg/L. Nevertheless, the prediction model is showing a coefficient of determination above 0.75 and is therefore regarded as reliable.

Executive summary:

QSAR Toolbox prediction based on trend analysis

 

Prediction of EC50 (48h) Daphnia magna for n-octyl methacrylate

 

Summary

 

Toxicity of the target chemical (1.05 mg/L) is predicted from category members using trend analysis based on 12 values within the range 0.0169 - 110 mg/L from 12 category members. Category members are single chemicals or mixtures and are selected based on the profile of the target chemical. Only chemicals having experimental data are listed in the category.

The target chemical FALLS within applicability domain of the prediction.

The data used for calculating the current prediction is taken from 19 experimental values selected from the following database(s):

1.   ECHA CHEM

 

NOTE: Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.

Description of key information

EC50 (72h) algae for n-octyl methacrylate predicted by QSAR TOOLBOX 3.4.0.17 database version: 3.8.8/3.1.2 from category trend analysis of 12 methacrylates is 1.05 mg/L (Evonik Oil Additives GmbH, 2017).

NOEC (72h) algae for n-octyl methacrylate predicted by QSAR TOOLBOX 3.4.0.17 database version: 3.8.8/3.1.2 from category trend analysis of 14 methacrylates is 0.171 mg/L (Evonik Oil Additives GmbH, 2017).

2-ethylhexyl methacrylate structural closely related to the target chemical n-octyl methacrylate has a similar log Kow. The experimental determined EC50 for 2-ethylhexyl methacrylate (ErC50(0-72h): 7.68 mg/l, Pseudokirchneriella subcapitata, OECD 201, MoE 1998) is in the range between 1 and 10 mg/L supporting the results of the predicted

value for n-octyl methacrylate by OSAR TOOLBOX.

Key value for chemical safety assessment

EC50 for freshwater algae:

1.05 mg/L

EC10 or NOEC for freshwater algae:

0.171 mg/L

Additional information

There is no reliable key study available for n-octyl methacrylate but two valid predictions by QSAR TOOLBOX 3.4.0.17 database version: 3.8.8/3.1.2.

EC50 (72h) algae for n-octyl methacrylate predicted by QSAR TOOLBOX 3.4.0.17 database version: 3.8.8/3.1.2 from category trend analysis of 12 methacrylates is 1.05 mg/L (Evonik Oil Additives GmbH, 2017).

NOEC (72h) algae for n-octyl methacrylate predicted by QSAR TOOLBOX 3.4.0.17 database version: 3.8.8/3.1.2 from category trend analysis of 14 methacrylates is 0.171 mg/L (Evonik Oil Additives GmbH, 2017).

No data are available for marine algae. With methacrylic acid, the common metabolite of all esters of the lower methacrylate category, an investigation with a series of 10 marine algae gave no indication of a higher sensitivity of marine species. To the contrary, EC50 values and NOECs tended to be higher than the corresponding freshwater data.