1-cyclohexylethanol

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Remarks:

ErC50

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

2017 - 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:

The Executive summary of the QSAR prediction is presented in the endpoint summary. The QMRF and QPRF documentation files are included below in the Attached justification section.

Qualifier:

according to guideline

Guideline:

other: IR/CSR Guidance R.6 QSARs and grouping of chemicals, May 2008

Version / remarks:

In the QMR attached the model specifications are presented. In this QMR is referenced to the Methodology document for the ecological Structure-Activity Relationship model (ECOSAR) Class Programm MS Windows v1.11'. United States Environmental Protection Agency, Office of Pollution Prevention and Toxics, Washington DC (2012).

Deviations:

not applicable

GLP compliance:

no

Test organisms (species):

other: green algae

Water media type:

freshwater

Total exposure duration:

72 h

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

18.7 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: QSAR predicted value

Remarks:

ECOSAR Class: Neutral organics

Validity criteria fulfilled:

yes

Remarks:

The ECOSAR-Neutral organics equation is valid when using the OECD criteria. In addition, N=41 and R2 is 0.68.

Conclusions:

ECOSAR v1.11 predicted that the 72h-ErC50 of Veilex #3 to green algae is 18.7 mg/L.

Executive summary:

The acute algae ErC50 for the neutral organic substance Veilex #3 is predicted to be 18.7 mg/L based on the ECOSAR SAR for neutral organics using an estimated log Kow of 2.546, molecular weight of 128.22 and the equation: Log 96h-EC50 (mmol/L) = -0.6922 log Kow + 0.9253. The 96h-EC50 is considered equivalent to the 72h ErC50 as defined in OECD TG 201.

Veilex #3 is in the applicability domain of the ECOSAR prediction because: a) Veilex #3 is an alcohol presenting the toxicity solely by its bioavailability (i.e. without fragments that activate this alcohol); b) its estimated log Kow is 2.546 (=< 6.4); c) its MW is 128.22 (=< 1000); and; d) the toxicity predicted is below its measured water solubility of 5163 mg/L. Though the estimated log Kow is >0.5 higher than the measured log Kow (of 1.6) the estimated log Kow has been used being considered the conservative approach and is therefore considered acceptable.

A fairly close analogue available in the ECOSAR training set is 2-Ethylhexanol (CAS# 104-76-7, with an estimated Log Kow of 2.7 and molecular weight of 130) with an experimental toxicity of 12 mg/L and an ECOSAR prediction of 14.1 mg/L, presenting the limited uncertainty of the prediction for 2-Ethylhexanol and thus also for Veilex #3.

The fit in the applicability domain and the availability of an analogue in the training set results in limited uncertainty of the Veilex #3 prediction. This shows that the prediction is reliable and a Klimisch 2 can be assigned. In accordance with REACH Annex XI, the validity of the (Q)SAR is documented in a QMR for acute algae toxicity on neutral organics (see attached report). The adequate and reliable documentation, presented in the Attached justification section, further supports this prediction.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Remarks:

ErC10/NOEC

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

2017 - 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:

The Executive summary of the QSAR prediction is presented in the endpoint summary. The QMRF and QPRF documentation files are included below in the Attached justification section.

Qualifier:

according to guideline

Guideline:

other: REACH Guidance R.6: QSARs and grouping of chemicals. Version May 2008.

Version / remarks:

In the QMR attached the model specifications are presented. In this QMR is referenced to the Methodology document for the ecological Structure-Activity Relationship model (ECOSAR) Class Programm MS Windows v1.11'. United States Environmental Protection Agency, Office of Pollution Prevention and Toxics, Washington DC (2012).

Deviations:

not applicable

GLP compliance:

no

Test organisms (species):

other: green algae

Water media type:

freshwater

Total exposure duration:

72 h

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

5.5 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: QSAR predicted value

Remarks:

ECOSAR class: Neutral organics

ECOSAR v1.11 predicted that the 72h-ErC10/NOEC of Veilex #3 to green algae is 5.5 mg/L.

Validity criteria fulfilled:

yes

Remarks:

The ECOSAR-Neutral organics equation is valid when using the OECD criteria. In addition, N=34 and R2 is 0.70.

Conclusions:

ECOSAR v1.11 predicted that the 72h-ErC10 of Veilex #3 to green algae is 5.5 mg/L.

Executive summary:

The chronic algae ErC10/NOEC for the neutral organic Veilex #3 is predicted to be 5.5 mg/L based on the ECOSAR SAR for neutral organics using an estimated log Kow of 2.546, molecular weight of 128.22 and the equation: Log 96h ChV (mmol/L) = -0.6029 log Kow + 0.1648. The 96-h ChV is considered equivalent to the 72-h ErC10/NOEC as defined in OECD TG 201.

Veilex #3 is in the applicability domain of the ECOSAR prediction because: a) Veilex #3 is an alcohol presenting the toxicity solely by its bioavailability (i.e. without fragments that activate this alcohol); b) its estimated log Kow is 2.546 (=< 8.0); c) its MW is 128.22 (=< 1000); and; d) the toxicity predicted is below its measured water solubility of 5163 mg/L. Though the estimated log Kow is >0.5 higher than the measured log Kow (of 1.6) the estimated log Kow has been used being considered the conservative approach and is therefore considered acceptable.

A fairly close analogue available in the ECOSAR training set is 2-Ethylhexanol (CAS# 104-76-7, with an estimated log Kow of 2.7 and molecular weight of 130) with an experimental toxicity of 2 mg/L and an ECOSAR prediction of 4.3 mg/L, presenting the limited uncertainty of the prediction for 2-Ethylhexanol and thus also for Veilex #3.

The fit in the applicability domain and the availability of an analogue in the training set results in limited uncertainty of the Veilex #3 prediction. This shows that the prediction is reliable and a Klimisch 2 can be assigned. In accordance with REACH Annex XI, the validity of the (Q)SAR is documented in a QMR for chronic algae toxicity on neutral organics (see attached report). The adequate and reliable documentation, presented in the Attached justification section, further supports this prediction.

Description of key information

ECOSAR v1.11 for neutral organics predicts that the 72h-ErC50 of Veilex #3 to green algae is 18.7 mg/L.

ECOSAR v1.11 for neutral organics predicts that the 72h-ErC10 of Veilex #3 to green algae is 5.5 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

18.7 mg/L

EC10 or NOEC for freshwater algae:

5.5 mg/L

Additional information

Acute Algae Toxicity:

The acute algae ErC50 for the neutral organic substance Veilex #3 is predicted to be 18.7 mg/L based on the ECOSAR SAR for neutral organics using an estimated log Kow of 2.546, molecular weight of 128.22 and the equation: Log 96h-EC50 (mmol/L) = -0.6922 log Kow + 0.9253. The 96h-EC50 is considered equivalent to the 72h ErC50 as defined in OECD TG 201.

Veilex #3 is in the applicability domain of the ECOSAR prediction because: a) Veilex #3 is an alcohol presenting the toxicity solely by its bioavailability (i.e. without fragments that activate this alcohol); b) its estimated log Kow is 2.546 (=< 6.4); c) its MW is 128.22 (=< 1000); and; d) the toxicity predicted is below its measured water solubility of 5163 mg/L. Though the estimated log Kow is >0.5 higher than the measured log Kow (of 1.6) the estimated log Kow has been used being considered the conservative approach and is therefore considered acceptable.

A fairly close analogue available in the ECOSAR training set is 2-Ethylhexanol (CAS# 104-76-7, with an estimated Log Kow of 2.7 and molecular weight of 130) with an experimental toxicity of 12 mg/L and an ECOSAR prediction of 14.1 mg/L, presenting the limited uncertainty of the prediction for 2-Ethylhexanol and thus also for Veilex #3.

The fit in the applicability domain and the availability of an analogue in the training set results in limited uncertainty of the Veilex #3 prediction. This shows that the prediction is reliable and a Klimisch 2 can be assigned. In accordance with REACH Annex XI, the validity of the (Q)SAR is documented in a QMR for acute algae toxicity on neutral organics (see attached report in the study record). The adequate and reliable documentation, presented in the Attached justification section of the study record, further supports this prediction.

Chronic Algae Toxicity:

The chronic algae ErC10/NOEC for the neutral organic Veilex #3 is predicted to be 5.5 mg/L based on the ECOSAR SAR for neutral organics using an estimated log Kow of 2.546, molecular weight of 128.22 and the equation: Log 96h ChV (mmol/L) = -0.6029 log Kow + 0.1648. The 96-h ChV is considered equivalent to the 72-h ErC10/NOEC as defined in OECD TG 201.

Veilex #3 is in the applicability domain of the ECOSAR prediction because: a) Veilex #3 is an alcohol presenting the toxicity solely by its bioavailability (i.e. without fragments that activate this alcohol); b) its estimated log Kow is 2.546 (=< 8.0); c) its MW is 128.22 (=< 1000); and; d) the toxicity predicted is below its measured water solubility of 5163 mg/L. Though the estimated log Kow is >0.5 higher than the measured log Kow (of 1.6) the estimated log Kow has been used being considered the conservative approach and is therefore considered acceptable.

A fairly close analogue available in the ECOSAR training set is 2-Ethylhexanol (CAS# 104-76-7, with an estimated log Kow of 2.7 and molecular weight of 130) with an experimental toxicity of 2 mg/L and an ECOSAR prediction of 4.3 mg/L, presenting the limited uncertainty of the prediction for 2-Ethylhexanol and thus also for Veilex #3.

The fit in the applicability domain and the availability of an analogue in the training set results in limited uncertainty of the Veilex #3 prediction. This shows that the prediction is reliable and a Klimisch 2 can be assigned. In accordance with REACH Annex XI, the validity of the (Q)SAR is documented in a QMR for chronic algae toxicity on neutral organics (see attached report in the study record). The adequate and reliable documentation, presented in the Attached justification section of the study record, further supports this prediction.