Propanoic acid, 2-hydroxy, C12-C16 (even numbered) alkyl esters

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Calculation of the LC50 of Ceraphyl 41 based on the individual QSAR data for the C12-C15 lactates.

Justification for type of information:

QSAR prediction: migrated from IUCLID 5.6

Reason / purpose for cross-reference:

(Q)SAR model reporting (QMRF)

Principles of method if other than guideline:

Calculation of the LC50 of a mixture based on individual LC50 values for the components assuming a similar mode of action.

GLP compliance:

no

Test organisms (species):

other: Fresh water algae

Water media type:

freshwater

Total exposure duration:

96 h

Key result

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

0.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Ceraphyl 41

Basis for effect:

growth rate

Key result

Duration:

4 d

Dose descriptor:

other: ChV

Effect conc.:

0.091 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Description of key information

Value calculated based on ECOSAR estimated individual ErC50 values for the C12, C14 and C16 lactates being the main constituents of Propanoic acid, 2-hydroxy, C12-C16 (even numbered) alkyl esters.

Key value for chemical safety assessment

EC50 for freshwater algae:

0.097 mg/L

EC10 or NOEC for freshwater algae:

0.091 mg/L

Additional information

Estimation of the EC50 ofPropanoic acid, 2-hydroxy, C12-C16 (even numbered) alkyl estersfor growth rate of fresh-water algea:

Assumption: Similar Mode of Action for C12-15 lactates

f=fraction of chemical in mixture

Calculation:

	f	EC50	1/EC50	f/EC50
C12-lactate	0.6	0.378	2.646	1.5873
C14-lactate	0.3	0.086	11.628	3.4884
C16-lactate	0.1	0.019	52.632	5.2632
			Σf/EC50	10.339
EC50 - Propanoic acid, 2-hydroxy, C12-C16 (even numbered) alkyl esters			0.097	mg/L

Estimation of the chronic value of Propanoic acid, 2-hydroxy, C12-C16 (even numbered) alkyl esters for fresh water algae:

Calculated based on QSAR values for Ester Toxicity:

Lactate	ChV	1/ChV	f	f/ChV
Dodecyl lactate	0.235	4.255	0.60	2.5532
Tetradecyllactate	0.074	11.51	0.30	4.0541
Hexadecyllactate	0.023	43.47	0.10	4.3478
			Σf/ChV	10.96
ChV ofPropanoic acid, 2-hydroxy, C12-C16 (even numbered) alkyl esters				0.091

f= estimated average fraction of chemical in mixtures

Based on the analytical results of the 96h algal test with octyl lactate in the referred study, alkyl lactates with C-chains of 8 carbons or more, degrade rapidly due to hydrolysis and bacterial activity.