Hexadecyl lactate

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

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:

1. SOFTWARE: ECOSAR Program (v1.10)

2. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL: O=C(OCCCCCCCCCCCCCCCC)C(O)C

3. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
- Defined endpoint: LC50
----------------------------------------------------------------------------------------------------
Class Specific LogKow Cut-Offs
----------------------------------------------------------------------------------------------------
If the log Kow of the chemical is greater than the endpoint specific cut-offs
presented below, then no effects at saturation are expected for those endpoints.

Esters:
----------------------------------------------------------------------------------------------------
Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50, Mysid LC50)
Maximum LogKow: 6.0 (Fish 14-day LC50; Earthworm LC50)
Maximum LogKow: 6.4 (Green Algae EC50)
Maximum LogKow: 8.0 (ChV)

Baseline Toxicity SAR Limitations:
----------------------------------------------------------------------------------------------------
Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50)
Maximum LogKow: 6.4 (Green Algae EC50)
Maximum LogKow: 8.0 (ChV)
----------------------------------------------------------------------------------------------------
4. ADEQUACY OF THE RESULT
- Data can be used to determine the classification category and M-factor.

Principles of method if other than guideline:

ECOSAR v1.1 Class-specific Estimations based on Esters or Baseline toxicity.

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

Remarks:

Freshwater

Effect conc.:

0.019 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

96 h

Dose descriptor:

EC50

Remarks:

Marine water

Effect conc.:

0.008 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

 

--------------------------------------

ECOSAR v1.1 Class-specific Estimations

--------------------------------------

Esters

                                                                   Predicted

ECOSAR Class                Organism           Duration End Pt  mg/L (ppm)

=========================== ================== ======== ======  ==========

Esters                    : Fish               96-hr    LC50       0.076

Esters                    : Daphnid            48-hr    LC50       0.096

Esters                    : Green Algae        96-hr    EC50       0.019

Esters                    : Fish                         ChV        0.002

Esters                    : Daphnid                      ChV        0.017

Esters                    : Green Algae                  ChV        0.023

Esters                    : Fish (SW)          96-hr    LC50       0.087

Esters                    : Mysid              96-hr    LC50       0.008

Esters                    : Fish (SW)                    ChV        0.029

Esters                    : Mysid (SW)                   ChV    4.39e-005

Esters                    : Earthworm          14-day   LC50     125.895 *

 

=========================== ================== ======== ======  ==========

Neutral Organic SAR       : Fish               96-hr    LC50       0.016

(Baseline Toxicity)       : Daphnid            48-hr    LC50       0.020

                          : Green Algae        96-hr    EC50       0.019

                          : Fish                         ChV        0.003

                          : Daphnid                      ChV        0.004

                          : Green Algae                  ChV        0.042

 

 Note: * = asterisk designates: Chemical may not be soluble enough to

       measure this predicted effect. If the effect level exceeds the

       water solubility by 10X, typically no effects at saturation (NES)

       are reported.

 

 

------------------------------

Class Specific LogKow Cut-Offs

------------------------------

If the log Kow of the chemical is greater than the endpoint specific cut-offs

presented below, then no effects at saturation are expected for those endpoints.

 

Esters:

------

Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50, Mysid LC50)

Maximum LogKow: 6.0 (Fish 14-day LC50; Earthworm LC50)

Maximum LogKow: 6.4 (Green Algae EC50)

Maximum LogKow: 8.0 (ChV)

 

Baseline Toxicity SAR Limitations:

---------------------------------

Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50)

Maximum LogKow: 6.4 (Green Algae EC50)

Maximum LogKow: 8.0 (ChV)

 

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Test Item Name CERAPHYL® 41
CAS Number 93925-36-1
Batch/Lot Number 0001749388
Analysed Purity 100 % (Refer Certificate of Analysis in APPENDIX 7)
Manufactured by Ashland Inc.
Supplied to JRF by Ashland Inc.
Date of Manufacture June 18, 2014
Date of Expiry June 18, 2016
Appearance: Clear, water white to straw colored liquid
Storage Temperature: Ambient
Storage Container: In original container as supplied by the Sponsor

Analytical monitoring:

yes

Details on sampling:

The test solutions were analysed for concentration of dedocyl alcohol using the validated analytical method. Quantitative analysis of dodecanol, tridecanol, tetradecanol, dodecyl lactate, tridecyl lactate, tetradecyl lactate, and pentadecyl lactate was done in 100% WAF of CERAPHYL® 41 by area % normalization. Two replicates each of 100.5 mL were centrifuged at 2000 rpm for 10 minutes. Collected sample were centrifuged in order to remove algal cell. Samples were sent for test concentration analysis at 0 h.. Same procedure was followed for sample collection at 24 h, 48 h and 72 h.

Details on test solutions:

Quantity of 202.6 mg CERAPHYL® 41 were weighed in two replicates, and made up to 2000 mL with sterile distilled water in two different glass bottles (stock A and B) and kept for continuous stirring using magnetic stirrer for approximate 24 h at room temperature. After stirring, test solutions were kept for re-equilibrium for approximate 24 h. After phase separation, test solutions were collected from lower portion by “L” shaped glass tube without disturbing the phase. Volume of 1200 mL was collected from each bottle and mixed together (stock C). To prepared the concentration of 100% WAF prepared at 100 mg CERAPHYL® 41/L and OECD medium preparation, after sample collection, total 31.2 mL of OECD stock solutions (24 mL of stock solution I, 2.4 mL of stock solution II, 2.4 mL of stock solution III, and 2.4 mL of stock solution IV) were added to the collected sample for preparation of algal medium and used for the treatment.
The initial cell concentration of the alga stock culture was determined as 6138 cells/mL by using a haemocytometer and microscope. Each replicate was inoculated with 0.5 mL of alga culture to obtain the required cell density.

Test organisms (species):

Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)

Details on test organisms:

Strain Number : ATCC 22662
Origin and Source of Culture: American Type Culture Collection, 10801, University of Boulevard, Manassas, Virginia, 20110-2209, USA
Subculture Maintained at : Jai Research Foundation
Date of Receipt (at JRF) : May 13, 2010
Date of Last Subculture : January 19, 2016
Method of Cultivation : Static condition

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test temperature:

22 - 24 °C

pH:

8.0 - 8.2

Nominal and measured concentrations:

100% WAF prepared at 100 mg CERAPHYL® 41/L corresponding with an initially measured concentration of 1.8 mg/L

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 1.8 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

growth rate

Remarks on result:

other: Concentration refers to the nominal loading.

Description of key information

Estimation of the endpoint value for acute toxicity to invertebrates was based on a GLP study with C12-15 alkyl lactates, supported by EC50 values estimated by ECOSAR v. 1.1 (QSAR). C12-15 alkyl lactates were tested in a static 72-h test with Pseudokirchneriella subcapitata as test organism. The EC50 of C12-15 alkyl lactates was above its solubility limit, i.e. a TWA of 1.8 mg/L. Based on ECOSAR v1.1, EC50 of hexadecyl lactate for fresh water algae  = 0.019 mg/L, and for sea water algae = 0.008 mg/L. These values were based on the Ester class. Hence, these key values reflect a worse case scenario.

Key value for chemical safety assessment

EC50 for freshwater algae:

0.019 mg/L

EC50 for marine water algae:

0.008 mg/L