Octahydro-2H-1-benzopyran-2-one

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 ECOSAR-prediction is presented below. The accompanying files are attached in the present record.
The acute Daphnia EC50 for the ester Bicyclononalactone is predicted to be 83 mg/L based on the ECOSAR SAR for esters using an estimated log Kow of 1.55, molecular weight of 154.21 and the equation: Log 48h-LC50 (mmol/L) = -0.6305 (log Kow) + 0.7049. The LC50 in ECOSAR is considered equivalent to the EC50 as defined in OECD TG 202. Bicyclononalactone is in the applicability domain of the ECOSAR prediction because: a) Bicyclononalactone is an ester presenting the toxicity solely by its bioavailability (i.e. without fragments that activate this ester); b) its log Kow is 1.55 (=< 5); c) its MW is 154.21 (< 1000); and; d) the toxicity predicted is below its measured water solubility of 3462 mg/L. The measured and predicted log Kows of Bicyclononalactone are 1.4 and 1.55, respectively, not indicating additional uncertainty. The ECOSAR training set substances with similar log Kows and the IFF types of esters (QMR) show that the predictions are roughly in line and do not indicate additional uncertainty other than what can be expected from experimental information. The fit in the applicability domain and the availability of an analogue in the training set results in limited uncertainty of the Bicyclononalactone 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 esters (see attached report). The adequate and reliable documentation, presented in the report, further supports this prediction.

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

Deviations:

not applicable

GLP compliance:

no

Specific details on test material used for the study:

SMILES: O=C(OC(C(CCC1)C2)C1)C2

Test organisms (species):

Daphnia sp.

Water media type:

freshwater

Total exposure duration:

48 h

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

83 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: QSAR predicted value

ECOSAR v1.11 predicted that the 48h-EC50 of Bicyclononalactone to Daphnia is 83 mg/L.

Validity criteria fulfilled:

yes

Remarks:

The ECOSAR-Ester equation is valid when using the OECD criteria. In addition, N=40 and R2 is 0.80

Conclusions:

ECOSAR v1.11 predicted that the 48h-EC50 of Bicyclononalactone to Daphnia is 83 mg/L.

Executive summary:

ECOSAR v1.11 predicted that the 48h-EC50 of Bicyclononalactone to Daphnia is 83 mg/L.

Please refer to the section "Justification for type of information".

Description of key information

ECOSAR v1.11 predicted that the 48h-EC50 of Bicyclononalactone to Daphnia is 83 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

83 mg/L

Additional information

Please refer to the section "Justification for type of information".