Propanoic acid, 2-hydroxy-, propyl ester, (2S)-

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Justification for type of information:

The acute aquatic effect concentration was predicted using an equation developed by the authors, using the log Kow as the predictive variable. The relationship between log Kow and acute aquatic effect concentrations for fish was developed using four different lactates (ethyl lactate, butyl lactate, 2-ethylhexyl lactate, octyl lactate), see table attached as image. The derived equation implies that acute fish toxicity is solely driven by the log Kow. The use of the log Kow as the predictive variable for acute aquatic toxicity was not justified by Bowmer et al. (1998).

Reason / purpose for cross-reference:

read-across source

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

168 mg/L

Conc. based on:

test mat.

Details on results:

Acute fish toxicity of four lactates excluding propyl lactate (ethyl lactate, butyl lactate, 2-ethylhexyl lactate, octyl lactate) and lactic acid was measured. An equation was derived to estimate aquatic toxicity of other lactates based on the log Kow, see table attached as image. This QSAR returns an LC50 for acute fish toxicity for propyl lactate of 168 mg/L.

Validity criteria fulfilled:

not applicable

Conclusions:

This derivation on the basis of the log Kow is not sufficiently justified and thus the predicted LC50 value for propyl lactate is regarded as not reliable.

Executive summary:

On the basis of equations using the log Kow as predictor, acute fish toxicity was calculated, resulting in an LC50 of 168 mg/L.

The derivation of acute aquatic toxicity on the basis of the log Kow was based on four data points only (four measured LC50 values for fish). The approach using the log Kow as a basis for prediction of acute aquatic toxicity was not justified. Therefore, the predicted LC50 value of propyl lactate is regarded as not reliable.

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reference 2

Endpoint:

short-term toxicity to fish

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

Qualifier:

according to guideline

Guideline:

other: ECHA guidance on information requirements and chemical safety assessment, chapter R.6: QSARs and grouping of chemicals

Deviations:

no

GLP compliance:

no

Specific details on test material used for the study:

SMILES: C(=O)(C(C)O)OCCC

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

55 mg/L

Remarks on result:

other: calculated

Validity criteria fulfilled:

yes

Conclusions:

The substance falls within the applicability domain of the model. The estimated LC50 for propyl-(S)-lactate is 55 mg/L

Executive summary:

For the determination of the acute toxicity to fish value the 'Leadscope Enterprise model for acute toxicity to fathead minnow (96-h mortality, LC50)' as included in the Danish QSAR Database, has been applied. Based on the calculated 96-h LC50 value of 55 mg/L it can be concluded that propyl-(S)-lactate shows low acute toxicity to fish within the 10–100 mg/L range.

Description of key information

The LC50 for acute fish toxicity of Propyl (S)-lactate is predicted to be 55 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

ca. 55 mg/L

Additional information

A recent and valid QSAR calculation (Leadscope, Danish QSAR data base) is used as the key study, resulting in an LC50 of 55 mg/L. An older publication, reporting a non-validated simple QSAR model (regression based, scarce data set) is considered unreliable hence used as supportive data only. The corresponding LC50 is reported to be 168 mg/L.