Octyl methacrylate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

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 3.3.0.132

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):

not specified

Details on test organisms:

prediction based on the following species:
Lepomis macrochirus
Pimephales promelas
Oncorhynchus mykiss
Brachydanio rerio
Oryzias latipes
Poecilia reticulata

Test type:

other: QSAR predicted value

Total exposure duration:

96 h

Key result

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

2.7 mg/L

Nominal / measured:

not specified

Conc. based on:

other: QSAR predicted value

Basis for effect:

mortality (fish)

Remarks on result:

other: QSAR predicted value

Sublethal observations / clinical signs:

QSAR TOOLBOX 3.4.0.17 (database version: 3.8.8/3.1.2) predicted that n-octyl methacrylate has a LC50 of 2.70 mg/L (Fish).

Toxicity of the target chemical is predicted from category members using trend analysis based on 13 values within the range of 4.56 - 444 mg/L from 13 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 15 experimental values selected from the following database(s):

1. Ökotox_Methacrylate_Toolbox_incl 1

Validity criteria fulfilled:

yes

Conclusions:

LC50 (96h) fish 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 13 methacrylates is 2.70 mg/l.

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 (2.70 mg/L) is predicted from category members using trend analysis based on 13 values within the range of 4.56 - 444 mg/L from 13 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 15 experimental values selected from the following database(s):

1. Ökotox_Methacrylate_Toolbox_incl 1

 

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

LC50 (96h) fish 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 13 methacrylates is 2.70 mg/l (Evonik Oil Additives GmbH, 2017).

Furthermore for 2 -Ethylhexyl methacrylate an experimental LC50-96h = 2.78 mg/L on Oryzias latipes (OECD 203, GLP) is reported by Japanese MoE.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

2.7 mg/L

Additional information

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

EC50 (96h) fish 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 13 methacrylates is 2.70 mg/l

(Evonik Oil Additives GmbH, 2016). This value is supported by the experimental data with the structral analogue 2-Ethylhexyl methacrylate LC50-96h of 2.78 mg/L (MoE 1998).

Read across to stuctural analogue substance 2-Ethylhexyl methacrylate (2-EHMA) also a member of category (C1 -C8 Lower Alkyl Methacrylates).

In the case of the two octyl esters there is a high degree of confidence that data on the linear, n-octyl ester (n-OMA) can be read across to the branched, 2-Ethylhexyl ester based upon the very similar physical chemical properties, Michael addition reactivity, half-life within the body and ultimate metabolic fate, both of the parent ester as well as the alcohol metabolites.

One reliable key study is available on freshwater fish with 2-EHMA: A Japanese study (MoE 1998) on Oryszias latipes gives a LC50-96h of 2.78 mg/L. The results are broadly consistent with a QSAR developed for the lower alkyl methacrylates (Staples et al., 2009).

There is no data on marine fish, but studies with the common metabolite of the category, methacrylic acid, indicate that marine species are not expected to be more sensitive to methacrylates than freshwater species (Sverdrup, 2001).