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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
(Q)SAR
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The source experimental data for the model originates from one lab and one experimental series, highly supporting consistency. The consistency has been additionally confirmed by successful previous and preset QSAR treatment. The significant statistical quality (RMS, correlation coefficients etc.) of the model supports reliable predictions within the margins of the experimental error. The similarity of the analogues together with the correct estimates supports potential prediction consistency.
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report date:
2012

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Qualifier:
according to guideline
Guideline:
EU Method C.3 (Algal Inhibition test)
Principles of method if other than guideline:
Type of model: QSAR model 4.0.3 for Toxicity to algae of benzene derivatives version 2010-01-09
GLP compliance:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
Ethyl 2-cyano-3-ethoxyacrylate
EC Number:
202-299-5
EC Name:
Ethyl 2-cyano-3-ethoxyacrylate
Cas Number:
94-05-3
Molecular formula:
C8H11NO3
IUPAC Name:
ethyl 2-cyano-3-ethoxyacrylate
Details on test material:
- Name of test material (as cited in study report): ethyl-2-cyano-3-ethoxyprop-2-enoate

Test organisms

Test organisms (species):
Chlorella vulgaris

Study design

Test type:
other: QSAR

Results and discussion

Effect concentrations
Dose descriptor:
EC50
Effect conc.:
6 900 mg/L
Details on results:
log(1/EC50) = - 1.61
Reported statistics and error estimates:
The toxicity data are from one lab and one experiment series. The consistency additionally confirmed by previous QSAR treatment
Statistics:
max value: 3.1
min value: -4.06
standard deviation: 1.465
skewness: -0.422

Any other information on results incl. tables

Domains

- descriptor domain : All descriptor values for ethyl 2-cyano-3-ethoxyacrylate fall in the applicability domain (training set value ±30%).

- structural fragment domain : Ethyl 2-cyano-3-ethoxyacrylate is structurally relatively similar to the model compounds, the model contains compounds featuring short alkyl chains; unsaturated CN (including cyano groups) and CC bonds, ether and ester functionalities. The training set contains compounds of similar size to the studied molecule.

- mechanism domain : Ethyl 2-cyano-3-ethoxyacrylate is considered to be in the same mechanistic domain as the molecules in the training set as it is structurally similar to the model compounds.

- metabolic domain, if relevant : Ethyl 2-cyano-3-ethoxyacrylate is considered to be in the same metabolic domain as the molecules in the training set of the model due to the structural similarity.

Structural analogues:

CAS  smiles  source  log (EC50) exp / pred   
 80 -62 -6  C(C(C)=C)(OC)=O  training -2.24   -2.32
 96 -05 -9  C(C(C)=C)(OCC=C) =O  training  -1.42  -1.61
 24964-64-5  O=Cc1cc(C#N)ccc1  training  -0.57  -0.26

The experimental algal inhibition values for compounds of similar functionalities (unsaturated esters, cyano compounds) are mostly positioned in the low toxicity regions of the scales, depending on the molecular size and other functionalities (aromatic compounds showing slightly higher toxicities). The structural analogues are quite similar to the studied compound, covering most chemical features. The model also contains several other cyano-, ester- etc compounds but with additional functionalities (the model training set is biased towards aromatic compounds).

The descriptor values of the analogues are close to those of the studied compound. The analogues are considered to be within the same mechanistic domain. All the analogues are rather well estimated within the model.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The EC50 value of the substance, using a QSAR model 4.0.3 for Toxicity to algae of benzene derivatives, was predicted to be 6900 mg/l.

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