Benzeneacetaldehyde, cyclic acetal with glycerol

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Remarks:

ErC50 at 96h

Type of information:

(Q)SAR

Adequacy of study:

key study

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:

For this prediction one of the two main constituents are used for the prediction. This one constituent covers most of the substance identity and has the higher log Kow being more conservative for the prediction.
The short-term algae ErC50 for the neutral organic substance Phen Acetald Glycerine Acetal is predicted to be 123.49 mg/L based on the ECOSAR SAR for neutral organics using an estimated log Kow of 1.62, molecular weight of 194.23 and the equation: Log 72-96h-EC50 (mmol/L) = -0.6922 log Kow + 0.9253, that is 72-96h ErC50 (mg/L) = 10(-0.6922 log Kow + 0.9253) * MW.
Phen Acetald Glycerine Acetal is in the applicability domain of the ECOSAR prediction because: a) Phen Acetald Glycerine Acetal is an acetal with an additional alcohol group presenting the toxicity solely by its bioavailability (i.e. without fragments that activate this acetal and alcohol group); b) its log Kow is 1.62 (=< 6.4); c) its MW is 194.23 (=< 1000); and; d) the toxicity predicted is below its water solubility of 28841 mg/L.
The measured and predicted log Kows of Phen Acetald Glycerine Acetal present limited uncertainty in the log Kow descriptor value being < 0.5 (1.7 and 1.6, respectively).An ECOSAR Neutral organic analogue with a log Kow of 2.1 and a molecular weight of 129 has predicted value is 35.75 mg/L while the measured value is 90 mg/L, further limiting the uncertainty of the prediction. Phen Acetald Glycerine Acetal is an acetal with an additional alcohol group categorised as a neutral organic and is expected to have a similar uncertainty as the data in the training set. The ether in the vicinity of the alcohol is not expected to increase the reactivity of the alcohol being two C-atoms apart, the ether bond not being very electronegative, resulting in a pKa of the alcohol of > 14.
The fit in the applicability domain and the availability of an analogue in the training set results in limited uncertainty of the Phen Acetald Glycerine Acetal 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 study record, 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 v1.11'. United States Environmental Protection Agency, Office of Pollution Prevention and Toxics, Washington DC (2012).

GLP compliance:

no

Test organisms (species):

other: green algae

Water media type:

freshwater

Total exposure duration:

96 h

Key result

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

123.49 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: ECOSAR class: Neutral Organics

Details on results:

The ErC50 is 123.49 mg/L

Validity criteria fulfilled:

yes

Remarks:

The substance is in the applicability domain of the model.

Conclusions:

The 96-h ErC50 is 123.49 mg/L.

Executive summary:

See section: Justification of information.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Remarks:

EC10/NOEC

Type of information:

(Q)SAR

Adequacy of study:

key study

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:

For this prediction one of the two main constituents is used for the prediction. This one constituent covers most of the substance identity and has the higher log Kow being more conservative for the prediction.
The chronic algae ErC10 for the neutral organic Phen Acetald Glycerine Acetal is predicted to be 29.91 mg/L based on the ECOSAR SAR for neutral organics using an estimated log Kow of 1.62, molecular weight of 194.23 and the equation: Log 72-96h ErC10 (mmol/L) = -0.6029 log Kow + 0.1648, that is 72-96h ErC10 (mg/L) = 10(-0.6029 Log Kow + 0.1648) * MW.
Phen Acetald Glycerine Acetal is in the applicability domain of the ECOSAR prediction because: a) Phen Acetald Glycerine Acetal is an acetal with an additional alcohol group presenting the toxicity solely by its bioavailability (i.e. without fragments that activate this acetal and alcohol group); b) its log Kow is 1.62 (=< 8.0); c) its MW is 194.23 (=< 1000); and; d) the toxicity predicted is below its water solubility of 28841 mg/L.
The measured and predicted log Kows of Phen Acetald Glycerine Acetal present limited uncertainty in the log Kow descriptor value being < 0.5 (1.7 and 1.6, respectively). A fairly close analogue available in the ECOSAR training set with a Log Kow of 2.3 and molecular weight of 113 has an experimental toxicity of 5.7 mg/L and an ECOSAR prediction of 7.27 mg/L, supporting the reliability of the prediction. Phen Acetald Glycerine Acetal is an acetal with an additional alcohol group categorised as a neutral organic and is expected to have a similar uncertainty as the data in the training set. The ether in the vicinity of the alcohol is not expected to increase the reactivity of the alcohol being two C-atoms apart, the ether bond not being very electronegative, resulting in a pKa of the alcohol of > 14.
The fit in the applicability domain and the availability of an analogue in the training set results in limited uncertainty of the Phen Acetald Glycerine Acetal 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 study record, 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 v1.11'. United States Environmental Protection Agency, Office of Pollution Prevention and Toxics, Washington DC (2012).

GLP compliance:

no

Test organisms (species):

other: green algae

Water media type:

freshwater

Total exposure duration:

96 h

Key result

Duration:

96 h

Dose descriptor:

EC10

Effect conc.:

29.91 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: ECOSAR Class: Neutral Organics

Validity criteria fulfilled:

yes

Remarks:

The substance is in the applicability domain of the scientific valid model. In addition, N=34 and R2=0.7

Conclusions:

The ErC10 is 29.91 mg/L

Executive summary:

See 'Justification of Information' section.

Description of key information

EC50 for freshwater Algae: QPRF, 96hr Acute Algae ErC50: 123.49 mg/L

EC10 for freshwater Algae: QPRF, 96hr Chronic Algae ErC10: 29.91 mg/L

Key value for chemical safety assessment

EC50 for freshwater algae:

123.49 mg/L

EC10 or NOEC for freshwater algae:

29.91 mg/L

Additional information

For the executive summaries, see the Justification of information sections.