(Z)-N-octadecyldocos-13-enamide

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 Sep 2019 to 09 Jan 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Version / remarks:

2012

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.20 (Daphnia magna Reproduction Test)

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Samples of the fresh test preparations were taken on Days 0, 5, 12 and 20 and of the expired test preparations on Days 1, 6, 13 and 21. Duplicate samples were taken and stored frozen

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test item solutions were prepared by stirring an excess (10 mg/L) of test item in test water using a propeller stirrer at approximately 1500 rpm for 48 hours. After the stirring period any undissolved test item was removed by filtration (0.2 μm Gelman Acrocap filter, first approximate 500 mL used to pre-condition the filter was discarded) to produce the required 100% v/v saturated solution of the test item.
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Age at study initiation (mean and range, SD): not specified
- Stage and instar at study initiation: adult
- Method of breeding: parthenogenesis
- Feeding during test
- Food type: Each daphnid received approximately 5 to 20 μL of an algal suspension (Raphidocelis subcapitata) daily and approximately 5 μL of GM 300 fish food suspension on Days 0 to 3. Feeding was at a level of approximately 0.1 to 0.2 mg carbon/daphnid/day, dependent on the age and size of the animals. Equal amounts of food were given to each daphnid.

ACCLIMATION
- Acclimation period: not specified
- Acclimation conditions (same as test or not): not specified
- Type and amount of food: Each culture was fed daily with a mixture of algal suspension (Raphidocelis subcapitata (formally known as Pseudokirchneriella subcapitata)) and GM300 fish food suspension.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

21 d

Hardness:

see in the "Any other information on results incl. tables" section

Test temperature:

see in the "Any other information on results incl. tables" section

pH:

see in the "Any other information on results incl. tables" section

Dissolved oxygen:

see in the "Any other information on results incl. tables" section

Salinity:

n.a.

Conductivity:

n.a.

Nominal and measured concentrations:

see in the "Any other information on results incl. tables" section

Details on test conditions:

TEST SYSTEM
- Test vessel: glass vessel
- Type (delete if not applicable): closed
- Aeration: no, the diluent water only was aerated prior to use.
- Renewal rate of test solution (frequency): Day 0 to 1, 5 to 6, 12 to 13 and 20 to 21
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10
- No. of vessels per vehicle control (replicates): n.a.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted Elendt M4 medium
- Details in the "Any other information on results incl. tables" section

OTHER TEST CONDITIONS
- Photoperiod / Light intensity: 16 hours light (not exceeding 1500 Lux) and 8 hours darkness with 20 minute dawn and dusk transition periods for 21 days.


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Immobilization
- Reproduction
- Body lenght
=> intervals: Days 0, 5, 12 and 20 and of the expired test preparations on Days 1, 6, 13 and 21

TEST CONCENTRATIONS
- saturated solution of the test item i.e. 0.052 µg/L

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

>= 0.052 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

immobilisation

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

>= 0.052 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

>= 0.052 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

>= 0.052 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 0.052 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

>= 0.052 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 0.052 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

>= 0.052 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

immobilisation

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 0.052 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

immobilisation

Details on results:

- Behavioural abnormalities: none
- Observations on body length and weight: none
- Other biological observations: none
- Mortality of control: none
- Other adverse effects control: none
- Immobilisation of control: none
- Abnormal responses: none

 

Summary of Findings Following the Exposure of Daphnia magna for 21 Days

Geometric Mean Measured Concentration (μg/L)	Parental (P1) Generation Mortalities (Initial Population = 10 – Control Group) (Initial Population = 9 – Test Group)			Total Number of Live Young	Number of Live Young from Parents Surviving to the End of the Test		Number of Live Young at the End of the Test Excluding Parents that were Accidental or Inadvertent Mortalities
	Total	Accidental	Inadvertent		Total	Average per Parent	Total	Average per Parent
Control	1	0	1	1463	1463	163	1463	163
0.052	1	0	1	1393	1311	164	1311	164

 

Summary of Daily Observations

Day	Geometric Mean Measured Concentration (μg/L)
	Control		0.052
	Adults Surviving	Live Young	Adults Surviving	Live Young
1	10	0	9		0
2	10	0	9		0
3	10	0	9		0
4	9	0	9		0
5	9	0	9		0
6	9	0	9		0
7	9	0	9		0
8	9	141	9		86
9	9	0	9		39
10	9	0	9		0
11	9	272	9		209
12	9	0	9		2
13	9	0	9		0
14	9	317	9		290
15	9	0	9		0
16	9	0	9		0
17	9	382	9		290
18	9	0	9		84
19	9	0	8		0
20	9	123	8		160
21	9	228	8		151
TOTALS	9	1463	8		1311

 

 

Body Length of Surviving Adults at Day 21

Geometric Mean Measured Concentration (μg/L)	Individual Daphnia Lengths (mm)
	1	2	3	4	5	6	7	8	9	10	Av	SD
Control	4.1	4.1	4.0	4.1	-	4.0	4.0	4.1	4.1	4.2	4.08	0.07
0.052	-	4.0	4.2	4.0	-	4.2	4.2	4.0	4.0	4.1	4.09	0.10

 

 

Reconstituted Water – Elendt M4 Medium

Main Compounds mg/L		Trace Elements* μg/L			Vitamins μg/L
CaCl2.2H2O	293.8	B	H3BO3	500	Thiamine HCl	75
MgSO4.7H2O	123.3	Fe	FeSO4.7H2O†	200	Cyanocobalamine (B12)	1.0
KCl	5.8	Mn	MnCl2.4H2O	100	Biotin (B6)	0.75
NaHCO3	64.8	Li	LiCl	50
Na2SiO3.9H2O	10.0	Rb	RbCl	50
NaNO3	0.274	Sr	SrCl2.6H2O	50
KH2PO4	0.143	Br	NaBr	12.4
K2HPO4	0.184	Mo	Na2MoO4.2H2O	25.2
		Cu	CuCl2.2H2O	6.4
		Zn	ZnCl2	6.3
		Co	CoCl2.6H2O	2.5
		I	KI	2.5
		Se	Na2SeO3	1.0
		V	NH4VO3	0.3
		EDTA	Na2EDTA.2H2O	2500

Water Hardness: 2.5 mmol/L (= 250 mg/L as CaCO3) Alkalinity: 0.9 mmol/L

 

 

validation criteria

	Required	Actual
Control mortality	=<20%	10%
Mean number of live young per surviving adult (control group)	>=60 after 21 days	163
Coefficient of variation for control group*	=< 25%	5.4%
Ephippia produced	0	0
Dissolved oxygen	>3 mg O2/L	≥8.5 mg O2/L
pH (control group)	6 to 9 Variation =< 1.5	7.6 to 8.7 1.1

Validity criteria fulfilled:

yes

Remarks:

For further details please refer to “Any other information on results incl. tables”.

Description of key information

EC10 (21 d) > 0.052 μg/L (geometric mean measured)

NOEC (21 d) >= 0.052 μg/L (geometric mean measured)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC10

Remarks:

No toxicity within the range of water-solubility

Effect concentration:

> 0.052 µg/L

Fresh water invertebrates

Dose descriptor:

NOEC

Remarks:

No toxicity within the range of water-solubility

Effect concentration:

>= 0.052 µg/L

Additional information

A study was performed to assess the chronic toxicity of the test item to Daphnia magna. The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (2012) No 211. Daphnia magna were exposed (10 replicates of a single daphnid per group) to solutions of test item at a nominal concentration of 100% v/v saturated solution (nominal concentration of 10 mg/L loading rate) for a period of 21 days under semi static conditions.

Due to the limited solubility of test item and low achievable test concentrations in the test media a "limit test" was conducted at a concentration of 100% v/v saturated solution to confirm that at the highest attainable test concentration no reduction of reproduction or adverse reactions to exposure were observed.

A nominal amount of test item (110 mg) was dispersed in 11 liters of test water with the aid of propeller stirring at approximately 1500 rpm for 48 hours. After 48 hours the stirring was stopped and any undissolved test item was removed by filtration through a 0.2 μm Gelman Acrocap filter (first approximate 500 mL discarded in order to pre-condition the filter) to give a 100% v/v saturated solution.

The concentration and stability of the test item in the test preparations were verified by chemical analysis on Days 0, 5, 12 and 20 (fresh media) and on Days 1, 6, 13 and 21 (expired media).

The numbers of live and dead adult Daphnia and young daphnids (live and dead) were determined daily. The Daphnia were fed daily with a mixture of algal suspension and GM 300 fish food suspension for Days 0 to 3 and from Day 4 onwards were fed an algal suspension only.

 Analysis of the fresh test preparations on Days 0, 5, 12 and 20 showed measured test concentrations to range from 0.025 to 0.094 μg/L. A general decline in measured test concentration of the old test preparations on Days 1, 6, 13 and 21 was observed to be between 0.035 to 0.062 μg/L and hence it was considered appropriate to calculate the results based on the geometric mean measured test concentration in order to give a “worst case” analysis of the data. The geometric mean measured concentration for the 100% v/v saturated solutions was determined to be 0.052 μg/L.

Exposure of Daphnia magna to the test item resulted in no effects with an EC10 (21 d) > 0.052 μg/L and a NOEC (21 d) >= 0.052 μg/L.