Benzeneacetaldehyde, cyclic acetal with glycerol

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

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 acute Daphnia EC50 for the neutral organic Phen Acetald Glycerine Acetal is predicted to be 191.6 mg/L based on the ECOSAR SAR for neutral organics using an estimated log Kow of 1.62, molecular weight (MW) of 194.23 and the equation: Log 48h EC50 (mmol/L) = -0.858 log Kow + 1.3848, that is 48h-EC50 (mg/L) = 10(-0.858 Log Kow + 1.3848) * 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 (=< 5); 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 (1.7 and 1.6, respectively) present limited uncertainty in the log Kow descriptor value being < 0.5. The ECOSAR analogue with a log Kow of 2.1, a molecular weight of 129 presents a predicted value of 45.46 mg/L, while the measured value is 28.5 mg/L, further showing limited uncertaintly. 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 Daphnia 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):

Daphnia sp.

Water media type:

freshwater

Total exposure duration:

48 h

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

191.6 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: ECOSAR class: Neutral Organics

Validity criteria fulfilled:

yes

Remarks:

The substance is in the applicability domain of the model.

Conclusions:

The Daphnia 48-h EC50 is 191.6 mg/L

Executive summary:

The acute Daphnia EC50 for the neutral organic Phen Acetald Glycerine Acetal is predicted to be 191.6 mg/L based on the ECOSAR SAR for neutral organics using an estimated log Kow of 1.62, molecular weight (MW) of 194.23 and the equation: Log 48h EC50 (mmol/L) = -0.858 log Kow + 1.3848, that is 48h-EC50 (mg/L) = 10^(-0.858 Log Kow + 1.3848) * 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 (=< 5); c) its MW is 194.23 (=< 1000); and; d) the toxicity predicted is below its water solubility of 28841 mg/L.

A fairly close analogue available in the ECOSAR training set is Quinoline (CAS #91-22-5 with a Log Kow of 2.1 and molecular weight of 129) with an experimental toxicity of 28.5 mg/L and an ECOSAR prediction of 45.46 mg/L, presenting the limited uncertainty of the prediction for Quinoline and thus also for Phen Acetald Glycerine Acetal.

The measured and predicted log Kows of Phen Acetald Glycerine Acetal present limited uncertainty in the log Kow descriptor value being < 0.5.

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 Daphnia toxicity on neutral organics (see attached report). The adequate and reliable documentation, presented in the study record, further supports this prediction.

Description of key information

EC50 for freshwater invertebrates: QPRF, 48h Acute Daphnia EC50: 191.6 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

191.6 mg/L

Additional information

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