1-cyclohexylethanol

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

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):

Daphnia sp.

Water media type:

freshwater

Total exposure duration:

48 h

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

20.3 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: QSAR predicted value

Remarks:

ECOSAR Class: Neutral organics

ECOSAR v1.11 predicted that the 48h-EC50 of Veilex #3 to Daphnia is 20.3 mg/L.

Validity criteria fulfilled:

yes

Remarks:

The ECOSAR-Neutral Organics equation is valid when using the OECD criteria. In addition, N=98 and R2 is 0.77

Conclusions:

ECOSAR v1.11 predicted that the 48h-EC50 of Veilex #3 to Daphnia is 20.3 mg/L.

Executive summary:

The acute Daphnia EC50 for the neutral organic Veilex #3 is predicted to be 20.3 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 48h LC50 (mmol/L) = -0.858 log Kow + 1.3848. The 48-h LC50 is considered equivalent to the 48-h EC50 as defined in OECD TG 202.

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 (=< 5); 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-Picoline, 5-ethyl (CAS# 104-90-5, with an estimated Log Kow of 2.4 and molecular weight of 121) which has an experimental toxicity of 39.6 mg/L and an ECOSAR prediction of 26.15 mg/L, presenting the limited uncertainty of the prediction for 2-Picoline, 5-ethyl 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 Daphnia 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 48h-EC50 of Veilex #3 to Daphnia is 20.3 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

20.3 mg/L

Additional information

The acute Daphnia EC50 for the neutral organic Veilex #3 is predicted to be 20.3 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 48h LC50 (mmol/L) = -0.858 log Kow + 1.3848. The 48-h LC50 is considered equivalent to the 48-h EC50 as defined in OECD TG 202.

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 (=< 5); 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-Picoline, 5-ethyl (CAS# 104-90-5, with an estimated Log Kow of 2.4 and molecular weight of 121) which has an experimental toxicity of 39.6 mg/L and an ECOSAR prediction of 26.15 mg/L, presenting the limited uncertainty of the prediction for 2-Picoline, 5-ethyl 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 Daphnia 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.