2,4,6-trimethylcyclohex-3-ene-1-methanol

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:

2016-2017

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 prediction is presented in the study record. The full justification is attached in the accompaning file attached to this study record.
The acute Daphnia EC50 for the neutral organic Isocyclogeraniol is predicted to be 5.6 mg/L based on the ECOSAR SAR for neutral organics using an estimated log Kow of 3.3, molecular weight of 154.25 and the equation: Log 48h LC50 (mmol/L) = -0.858 log Kow + 1.3848
Isocyclogeraniol falls within the applicability domain of the ECOSAR prediction because: a) isocyclogeraniol is a neutral organic presenting the toxicity solely by its bioavailability (i.e. without fragments that activate this chemical class); b) its log Kow is 3.3 (=< 5); c) its MW is 154.25 (< 1000); and; d) the toxicity predicted is below its measured water solubility of 656.2 mg/L.
There is limited uncertainty of the prediction. The measured and predicted log Kows of isocyclogeraniol are very similar. The measured EC50 values of the substances in the ECOSAR training with similar log Kows are similar to what is predicted for isocyclogeraniol. The Neutral Organic fragrance types of neutral organics present higher EC50 values, indicating that the calculated EC50 for isocyclogeraniol could be conservative (see QMR). 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 below, further supports this prediction.

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 v1.1'. United States Environmental Protection Agency, Office of Pollution Prevention and Toxics, Washington DC (2011).

GLP compliance:

no

Specific details on test material used for the study:

SMILES: OCC(C(CC(=C1)C)C)C1C

Test organisms (species):

Daphnia sp.

Water media type:

freshwater

Total exposure duration:

48 h

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

5.6 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 Isocyclogeraniol to Daphnia is 5.6 mg/L.

Validity criteria fulfilled:

yes

Remarks:

The ECOSAR-Neutral organic 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 Isocyclogeraniol to Daphnia is 5.6 mg/L.

Executive summary:

The acute Daphnia EC50 for the neutral organic Isocyclogeraniol is predicted to be 5.6 mg/L based on the ECOSAR SAR for neutral organics using an estimated log Kow of 3.3, molecular weight of 154.25 and the equation: Log 48h LC50 (mmol/L) = -0.858 log Kow + 1.3848

Isocyclogeraniol falls within the applicability domain of the ECOSAR prediction because: a) Isocyclogeraniol is a neutral organic presenting the toxicity solely by its Neutral organic mode of action (i.e. without fragments that activate this chemical class); b) its log Kow is 3.3 (=< 5); c) its MW is 154.25 (< 1000); and; d) the toxicity predicted is below its measured water solubility of 656.2 mg/L.

There is limited uncertainty of the prediction. The measured and predicted log Kows of Isocyclogeraniol are very similar, 3.6 and 3.3, respectively. The measured EC50 values of the substances in the ECOSAR training, with similar log Kows, are similar to what is predicted for Isocyclogeraniol. The Neutral Organic fragrance types of neutral organics present higher EC50 values, indicating that the calculated EC50 for Isocyclogeraniol could be conservative (see QMR). 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 of the QPR, present in the study record, further supports this prediction.

Description of key information

The acute Daphnia EC50 for the neutral organic Isocyclogeraniol is predicted to be 5.6 mg/L based on the ECOSAR SAR for neutral organics using an estimated log Kow of 3.3, molecular weight of 154.25 and the equation: Log 48h LC50 (mmol/L) = -0.858 log Kow + 1.3848

Isocyclogeraniol falls within the applicability domain of the ECOSAR prediction because: a) isocyclogeraniol is a neutral organic presenting the toxicity solely by its bioavailability (i.e. without fragments that activate this chemical class); b) its log Kow is 3.3 (=< 5); c) its MW is 154.25 (< 1000); and; d) the toxicity predicted is below its measured water solubility of 656.2 mg/L.

There is limited uncertainty of the prediction. The measured and predicted log Kows of isocyclogeraniol are very similar. The measured EC50 values of the substances in the ECOSAR training with similar log Kows are similar to what is predicted for isocyclogeraniol. The Neutral Organic fragrance types of neutral organics present higher EC50 values, indicating that the calculated EC50 for isocyclogeraniol could be conservative (see QMR). 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. The adequate and reliable documentation further supports this prediction.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

5.6 mg/L