Hexadecyl palmitate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes (incl. QA statement)

Remarks:

Ministerium für Arbeit, Integration und Soziales des Landes Nordrhein-Westfalen, Germany

Analytical monitoring:

yes

Details on sampling:

- Concentrations: control, 100 mg/L. The concentrations of tetradecyl myristate in the test media were analysed at test start directly after distribution of the stock test item WAF into the 60 mL glass beakers (fresh test media at test start). Furthermore, a second sample of the stock WAF was taken at this time to investigate a possible 'wall effect' of the used glass beakers. Another sample was taken at the end of the test after 48 hours (aged test media at test end).
- Sampling method: As the volume of the analytical sub-sample required for sampling was large compared to the total test media volume, the test item concentration was determined from samples taken from additionally prepared glass beakers. Five millilitres were pipetted directly into 20 mL extraction (centrifuge) tubes and 15 mL of purified water added. The pipette tips were rinsed multiple times and the surface wiped with a lint free paper towel prior taking the analytical sub-sample.
- Sample storage conditions before analysis: The samples were measured immediately after sampling without further storage.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test substance pellets were crushed by mortar and pestle and the Water Accommodated Fraction (WAF) prepared with the test item powder. A test preparation with a loading of 100 mg/L dilution water was prepared according to the OECD guideline No. 23, and stirred slowly at 300 rpm to avoid bubble and foam formation using a stirring bar on a magnetic stirrer for 48 h at room temperature (about 20 °C). Finally, the test preparation was filtered using a 0.2 µm membrane filter (Sartolab 150V, vacuum capsule sterile - Sartorius) to separate insoluble parts from the aqueous phase in accordance with the OECD guideline No. 29. The aqueous phase (WAF) was drawn off and used for testing. The control consisted of dilution water only and was not stirred for 48 h.
- Eluate: no
- Differential loading: yes
- Controls: yes, dilution water control

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: Obtained from the German Federal Environment Agency, Institut für Wasser-, Boden- und Lufthygiene, Germany. Specimens used in the test were bred in the laboratory at Fraunhofer IME.
- Age at study initiation (mean and range, SD): < 24 h
- Method of breeding: Adult Daphnia, at least 3 weeks old, were separated from the stock population by sieving. Batches of 30 - 50 animals were held at room temperature in ca. 1.8 L of dilution water for one week. During this week, the daphnids were fed daily with an algal suspension (Desmodesmus subspicatus) and LiquizellR. Algae growing in the log-phase were centrifuged and the pellet was re-suspended in a few mL of medium. Thirty milliliters of this suspension was given to 1 L of medium. The water was changed once per week. Newborn Daphnia (between 4 - 23 h old) were removed by wide-bore pipette (to avoid damage) and isolated in fresh dilution water for at least 1 h prior to being added randomly to the test vessels containing the appropriate test or control media.
- Feeding during test: no

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test temperature:

20.2 - 20.4 °C

pH:

7.91 - 8.49

Dissolved oxygen:

6.3 - 8.2 mg O2/L

Nominal and measured concentrations:

nominal: control, 100 mg/L
measured: < LOQ, 0.128 µg/L (geometric mean)

Details on test conditions:

TEST SYSTEM
- Test vessel
- Type: covered with a glass pane
- Material, size, headspace, fill volume: glass, 60 mL, headspace: 10 mL, fill volume: 50 mL
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Purified drinking water was used according to the OECD guideline. The purification included filtration with activated charcoal, passage through a lime-stone column and aeration. To avoid copper contamination, plastic water pipes were used for the test facilities. The water was aerated to the point of oxygen saturation.
- Chlorine: < 0.02 mg/L
- Alkalinity: 2 mmol/L
- Conductivity: 244.5 µS/cm
- Nitrate: 1.7 mg/L
- Nitrite: 0.005 mg/L
- Ammonium: < 0.01 mg/L
- Phosphate: 0.73 mg/L
- Culture medium different from test medium: no
- Intervals of water quality measurement: regularly

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light / 8 h dark
- Light intensity: 518 - 536 lux

EFFECT PARAMETERS MEASURED: After 24 h and 48 h, the number of immobile animals in each beaker was counted. The animals were considered to be immobile if they were not able to swim within 15 sec of gentle agitation of the test vessels. Any abnormalities in appearance and behaviour were also recorded.

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 1, 10 and 100 mg/L (nominal WAF)
- Results used to determine the conditions for the definitive study: EL50 > 100 mg/L

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

>= 0.128 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOELR

Effect conc.:

> 0.128 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 0.128 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOELR

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Details on results:

- Other biological observations: No signs of disease or stress were observed. All surviving specimens gave the impression of healthy condition.
- Mortality of control: 0%

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50/LC50: EC50 (24 h): 0.87 mg/L

Table1: Measured concentrations of tetradecyl myristate [µg/L].

Nominal loading	Test duration				Geometric mean
	Mean measured 0 h		Mean measured 48 h
[mg/L]	[µg/L]	% nominal	[µg/L]	% nominal	[µg/L]	[%]
100	0.172	1.72 E-4	0.096	9.59 E -5	0.128	1.28 E-4
Control	<LOQ	-	<LOQ	-	-	-

 

 Table 2: Immobility raw data

Geometric mean conc. [mg/L]	Control	100
0 h	5	5
	5	5
	5	5
	5	5
Number of replicates:	4	4
Total Introduced:	20.00	20.00
24 h	0	0
	0	0
	0	0
	0	0
Number of replicates:	4	4
Total Immobile:	0.00	0.00
48 h	0	0
	0	0
	0	0
	0	0
Number of replicates:	4	4
Total Immobile:	0.00	0.00

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

Refer to analogue justification provided in IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

>= 0.128 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

Source: CAS 3234-85-3, Evonik, 2012, D. magna, 48 h

Duration:

48 h

Dose descriptor:

LOELR

Effect conc.:

> 0.128 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

Source: CAS 3234-85-3, Evonik, 2012, D. magna, 48 h

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 0.128 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

Source: CAS 3234-85-3, Evonik, 2012, D. magna, 48 h

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

Source: CAS 3234-85-3, Evonik, 2012, D. magna, 48 h

Duration:

48 h

Dose descriptor:

LOELR

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

Source: CAS 3234-85-3, Evonik, 2012, D. magna, 48 h

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

Source: CAS 3234-85-3, Evonik, 2012, D. magna, 48 h

Conclusions:

No toxict effects to D. magna (OECD 202) up to the limit of water solubility (< 0.02 mg/L).

Description of key information

No acute effects up to the limit of water solubility (OECD 202, D. magna); read-across

Additional information

There is no study available assessing the short-term toxicity of the target substance hexadecyl palmitate (CAS 540-10-3) to aquatic invertebrates. Therefore, a read-across to the structurally related source substance tetradecyl myristate (CAS 3234-85-3) was conducted in accordance with Regulation (EC) No 1907/2006 Annex XI, 1.5. The source substance is characterized by a similar fatty acid chain length (C14, myristic acid) as well as fatty alcohol (C14, tetradecanol) as the target substance, which is composed of both a C16 fatty acid (palmitic acid) and fatty alcohol (hexadecanol). Hence, the source substance is considered a suitable representative for the assessment of the acute toxicity of the target substance to aquatic invertebrates. A detailed read-across justification is provided in in the analogue justification in IUCLID section 13.

The available study with the source substance tetradecyl myristate (CAS 3234-85-3) was conducted according to the OECD guideline 202 and GLP. In a static limit test, D. magna was exposed to a water accommodated fraction with a nominal loading level of 100 mg/L test item for 48 h. GC/EI-MS analysis at the beginning and end of exposure resulted in a measured geometric mean concentration of 0.128 µg/L. No immobilization was recorded after 48 h resulting in an EL50 of > 0.128 µg/L (measured, geometric mean) and > 100 mg/L (nominal), respectively.

Based on the structural and chemical similarity of the target and source substances, the target substance is expected to exhibit a similar ecotoxicological profile as the source substance. Therefore, it can be concluded that hexadecyl palmitate (CAS 540-10-3) will not exhibit short-term toxic effects to aquatic invertebrates up to the limit of water solubility (< 0.846 µg/L).