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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Reference
Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
(Q)SAR
Adequacy of study:
key study
Study period:
2018
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
Software Package: iSafeRat® HA-QSAR toolbox v2.4,
Contact KREATIS
Dr. Paul Thomas
KREATiS SAS
23, rue du Creuzat
38080 L’ISLE D’ABEAU
FRANCE

2. MODEL (incl. version number)
iSafeRat® HA-QSAR toolbox v2.4 – Algae 72h ErC50 ; including the following specific sub-models:
(i) non-polar narcosis (MechoA 1.1)
(ii) mono-/poly-esters whose hydrolysis products are narcotics (MechoA 2.1)
01 February 2014 (model development); 30 November 2017 (current model version)

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
See attached: ‘Prediction of acute toxicity of (10E)-oxacycloheptadec-10-en-2-one to an Algal Growth Inhibition Test (72-hour ErC50)’ version 1.0; dated 09 April 2018.

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
Full details of the method are provided in the attached QMRF named 'iSafeRat® HA-QSAR based on a holistic approach for predicting physicochemical and ecotoxicological endpoints’ version 1.8; 30 November 2017

5. APPLICABILITY DOMAIN
See ‘any other information on results incl. tables’.
See attached: ‘Prediction of acute toxicity of (10E)-oxacycloheptadec-10-en-2-one to an Algal Growth Inhibition Test (72-hour ErC50)’ version 1.0; dated 09 April 2018.

6. ADEQUACY OF THE RESULT
1) QSAR model is scientifically valid. 2) The substance falls within the applicability domain of the QSAR model. 3) The prediction is fit for regulatory purpose.
The prediction is adequate for the Classification and Labelling or risk assessment of the substance as indicated in REACH Regulation (EC) 1907/2006: Annex XI Section 1.3. Specifically when combined with further information such as physico-chemistry and environmental fate testing and modelling.
Guideline:
other: REACH Guidance on QSARs R.6, May/July 2008
Principles of method if other than guideline:
1. iSafeRat® HA-QSAR toolbox v2.4 – Algae 72h ErC50 ; including the following specific sub-models:
(i) non-polar narcosis (MechoA 1.1)
(ii) mono-/poly-esters whose hydrolysis products are narcotics (MechoA 2.1)
2. Aquatic Toxicity Assessment using the Additivity Approach or based on a constituent and worst-case approach
3. Assessment of Degradability and/or Bioaccumulation Potential for the purpose of Classification and Labelling
Specific details on test material used for the study:
Detailed information on the 'test material identity' is provided in the attached QSAR Prediction Reporting Format (QPRF) document including information on individual constituents.
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
0.21 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
growth rate

1. Defined Endpoint:

QMRF 3. Ecotoxic effects

QMRF 3.2. Short-term toxicity to algae (inhibition of the exponential growth rate)

Reference to type of model used and description of results:

iSafeRat® HA-QSAR toolbox v2.4 – Algae 72h ErC50 ; including the following specific sub-models:

(i) non-polar narcosis (MechoA 1.1)

(ii) mono-/poly-esters whose hydrolysis products are narcotics (MechoA 2.1)

01 February 2014 (model development); 30 November 2017 (current model version)

 

2. Description of results and assessment of reliability of the prediction:

See attachment QPRF: ‘Prediction of acute toxicity of (10E)-oxacycloheptadec-10-en-2-one to an Algal Growth Inhibition Test (72-hour ErC50)’ version 1.0; dated 09 April 2018.

Results:

(10E)-oxacycloheptadec-10-en-2-one: 72-h ErC50 = 0.23 mg/L

 

Inputs Used for Test Item: All modelling was based on input of SMILES notation for each constituent of the test item and the process relied on modelled or measured values for Kow and water solubility to define each constituent prediction. This approach is in line with the attached QMRF named ‘iSafeRat® HA-QSAR based on a holistic approach for predicting physicochemical and ecotoxicological endpoints’ version 1.8; 30 November 2017, and ECHA Guidance on Information Requirements and Chemical Safety Assessment Chapter R7.b for hazard assessment of substances.

For the purpose of concluding on classification and labelling for this substance:

1. Substance rapidly degradable: Yes

2. Log Kow: > 4.0 although BCF < 500 L/kg wet-wt (by validated QPRF prediction and additional evidence)

3. Selection of effect levels from most sensitive trophic species

 

Assessment of the substance within the applicability domain as documented within the corresponding QMRF named ‘iSafeRat® HA-QSAR based on a holistic approach for predicting physicochemical and ecotoxicological endpoints’ version 1.8; 30 November 2017 – section 5; indicates the substance:

(i) The water solubility value given as the input to the Ecotox module of the iSafeRat® Holistic HA-QSAR (actual: - 5.911) does not fall within the descriptor domain of the model between a log water solubility (in log (mol/L)) of - 5.57 to 0.93 where the ErC50 can be calculated. However, it falls between a log water solubility (in log (mol/L)) of -5.57 and -6.27 where the toxicity can be extrapolated. Expert judgement indicates, this prediction and conclusion is considered acceptable within the definitions of the applicability domain of the model. See QMRF section 5.2 for further details.

(ii) Falls within the structural fragment domain

(iii) Falls within the mechanistic domain of MechoA 2.1

  

3. Uncertainty of the prediction and mechanistic domain:

An External validation set is available for the chemical class used in this prediction however is not publicly available. Interested parties are invited to contact the model author. The QMRF has been peer reviewed by Joint Research Centre, ISPRA, Italy.

Full details on the training set, internal and external validations, as applicable are included in the attached QMRF named ‘iSafeRat® HA-QSAR based on a holistic approach for predicting physicochemical and ecotoxicological endpoints’ version 1.8; 30 November 2017. Interested parties are invited to contact the model author.

 

Uncertainty in the prediction relates to:

Statistical characteristics are provided (i) for the prediction: in the attached QPRF and (ii) for the model: in the attached QMRF, respectively.

Validity criteria fulfilled:
yes
Conclusions:
The results are adequate for the for the regulatory purpose.
Executive summary:

iSafeRat® HA-QSAR toolbox v2.4 – Algae 72h ErC50 ; including the following specific sub-models:

(i) non-polar narcosis (MechoA 1.1)

(ii) mono-/poly-esters whose hydrolysis products are narcotics (MechoA 2.1)

Endpoint values: (10E)-oxacycloheptadec-10-en-2-one: 72-h ErC50 = 0.23 mg/L

 

Adequacy of the QSAR:

1) QSAR model is scientifically valid. 2) The substance falls within the applicability domain of the QSAR model or is acceptably extrapolated in the (water solubility) descriptor domain, by expert judgement. 3) The prediction is fit for regulatory purpose.

The prediction is adequate for the Classification and Labelling or risk assessment of the substance as indicated in REACH Regulation (EC) 1907/2006: Annex XI Section 1.3. The assessment indicates that the prediction is suitable for the regulatory conclusion in accordance with the tonnage driven information requirements. Specifically, when combined with further information such as physico-chemistry and environmental fate testing and modelling.

Description of key information

QSAR EC50-72h (aquatic algae; growth rate) = 0.21 mg/L, iSafeRat® HA-QSAR toolbox v2.4, KREATIS SAS, 2018

Key value for chemical safety assessment

EC50 for freshwater algae:
0.21 mg/L

Additional information

iSafeRat® HA-QSAR toolbox v2.4 – Algae 72h ErC50 ; including the following specific sub-models:

(i) non-polar narcosis (MechoA 1.1)

(ii) mono-/poly-esters whose hydrolysis products are narcotics (MechoA 2.1)

Endpoint values: (10E)-oxacycloheptadec-10-en-2-one: 72-h ErC50 = 0.23 mg/L

 

Adequacy of the QSAR:

1) QSAR model is scientifically valid. 2) The substance falls within the applicability domain of the QSAR model or is acceptably extrapolated in the (water solubility) descriptor domain, by expert judgement. 3) The prediction is fit for regulatory purpose.

The prediction is adequate for the Classification and Labelling or risk assessment of the substance as indicated in REACH Regulation (EC) 1907/2006: Annex XI Section 1.3. The assessment indicates that the prediction is suitable for the regulatory conclusion in accordance with the tonnage driven information requirements. Specifically, when combined with further information such as physico-chemistry and environmental fate testing and modelling.

 

References for further information:

1. QMRF Title: ‘iSafeRat® HA-QSAR based on a holistic approach for predicting physicochemical and ecotoxicological endpoints’ version 1.8; 30 November 2017

2. QPRF Title: ‘Prediction of acute toxicity of (10E)-oxacycloheptadec-10-en-2-one to an Algal Growth Inhibition Test (72-hour ErC50)’ version 1.0; dated 09 April 2018.