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

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Remarks:

EC10/NOEC

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 is presented below.
The chronic algae ChV for the ester Bicyclononalactone is predicted to be 8.4 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 96h ChV (mmol/L) = -0.5583 (log Kow) - 0.4017. The endpoint is considered equivalent to the 72h-ErC10/NOEC as defined in OECD TG 201.
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 (=< 8.0); 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 much in line showing limited uncertainty. Bicyclononalactone is categorised as an ester and substances with similar Mode of Action used for in the ECOSAR training set and fragrance types of esters (see QMR) present conservative predictions and therefore the prediction has acceptable uncertainty.
The fit in the applicability domain and the somewhat conservative predictions results in limited uncertainty of the Bicyclononalactone prediction. This shows that the prediction is sufficiently 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 esters (see attached report). The adequate and reliable documentation, presented in the accompanying files attached to the study record, further supports this prediction.

Qualifier:

according to guideline

Guideline:

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

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):

other: green algae

Water media type:

freshwater

Total exposure duration:

72 h

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

8.4 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: ECOSAR Class: Esters

Remarks:

ChV is equivalent to EC10/NOEC

Details on results:

Bicyclononalactone prediction for chronic algae toxicity results in a 72h-ErC10 of 8.4 mg/L.

Validity criteria fulfilled:

yes

Remarks:

The ECOSAR-Ester equation is valid when using the OECD criteria. In addition, N=13 and R2 is 0.74

Conclusions:

ECOSAR v1.11 predicted that the 72h-ErC10 of Bicyclononalactone to green algae is 8.4 mg/L.

Executive summary:

The executive summary is presented in the 'Justification of information' section.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Remarks:

ErC50 at 72h

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:

Executive summary:
The acute algae ErC50 for the esters Bicyclononalactone is predicted to be 38 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 96-h EC50 (mmol/L) = -0.6993 (log Kow) + 0.4715. The 96h-EC50 is considered equivalent to the 72h ErC50 as defined in OECD TG 201. 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 (=< 6.4); 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 Kow are in the same range and do not indicate uncertainty for the predictions. The measured EC50 values of the substances in the ECOSAR training set with a similar log Kow are in the same range as predicted for Bicyclononalactone. The measured EC50 values for fragrance types of esters have higher values than the predicted ones. This means that the uncertainty of the predicted EC50 for acute algae is as can be expected from experimental testing. The fit in the applicability domain and the limited uncertainty of the prediction 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 esters (see attached report). The adequate and reliable documentation, presented in the accompanying files in the record, further supports this prediction.

Qualifier:

according to guideline

Guideline:

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

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):

other: green algae

Water media type:

freshwater

Total exposure duration:

72 h

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

38 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: QSAR predicted value; ECOSAR class: Esters

Validity criteria fulfilled:

yes

Remarks:

The ECOSAR-Ester equation is valid when using the OECD criteria. In addition, N=20 and R2 is 0.86

Conclusions:

ECOSAR v1.11 predicted that the 72h-EC50 of Bicyclononalactone to green algae is 38 mg/L.

Executive summary:

ECOSAR v1.11 predicted that the 72h-EC50 of Bicyclononalactone to green algae is 38 mg/L.

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

Description of key information

ECOSAR v1.11 predicted that the 72h-ErC50 of Bicyclononalactone to green algae is 38 mg/L.

ECOSAR v1.11 predicted that the 72h-ErC10 of Bicyclononalactone to green algae is 8.4 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

38 mg/L

EC10 or NOEC for freshwater algae:

8.4 mg/L

Additional information

The executive summaries are presented in the "Justification for type of information".