Amides, C16-C18 (even) , N,N'-ethylenebis

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:

01 Nov - 22 Nov 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

no

GLP compliance:

yes

Remarks:

according to the Japanese GLP Standard

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0, 100 mg/L
- Sampling method: 100 mL test solution was sampled directly from each test vessel six times, at day 8 (new: freshly prepared test solution), day 9 (old: old test solution before renewal), day 14 (new), day 15 (old), day 20 (new) and 21 (old).
- Sample storage conditions before analysis: analysis was conducted immediately after sampling, no storage

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: test item is immiscible with water and therefore a WAF was prepared by adding the test item in dilution water. After 30 minutes sonication, test water was stirred (750 rpm) for 24 hours at 20 °C. Test water was filtered with No. 2 filter paper.
- Controls: dilution water
- Evidence of undissolved material (e.g. precipitate, surface film, etc): test water was always colorless when it was freshly prepared.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: Incorporated Administrative Agency, National Institute for Environmental Studies, Tsukuba, Japan
- Age at study initiation: within 24 hours
- Feeding during test: yes
- Food type: Chlorella vulgaris
- Amount: 0.2 mg C/day

ACCLIMATION
- Acclimation period: 21 days (2005/10/04 - 2005/11/01)
- Acclimation conditions (same as test or not): similar to test condition (Renewal rate of water and density of animals: acclimation condition: three times in a week and 1 animal/80 mL, test condition: once in 24 hours and 5 animals/100 mL)
- Type and amount of food: Chlorella vulgaris, 0.15 mg C/day
- Feeding frequency: daily
- Health during acclimation (any mortality observed): no mortality, no presence of males and ephippia

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

21 d

Hardness:

238 - 242 mg/L (CaCO3)

Test temperature:

20.0 - 20.3 °C (20 ± 1 °C)

pH:

7.3 - 8.2

Dissolved oxygen:

7.1 - 8.8 mg/L (more than 60% of saturated oxygen)

Nominal and measured concentrations:

Nominal concentration: 100 mg/L of test substance
Measured concentration (time-weighted mean): 0.00564 mg/L of test substance

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL beaker
- Type: closed
- Material, fill volume: glass, 80 mL
- Aeration: not applied
- Renewal rate of test solution (frequency/flow rate): once in 24 hours
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt M4 medium
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: not adjusted
- Photoperiod: 16 hours in the light, 8 hours in the dark
- Light intensity: <800 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable)
- Mortality of parental animals: observed daily
- Numbers of juveniles produced per adult: counted daily after first brood production
- Time required to first brood production: observed

RANGE-FINDING STUDY
- Test concentrations: 0, 100 mg/L (loading rate)
- Results used to determine the conditions for the definitive study: Based on the acute toxicity study (test nummer A030055-2), EC50 of immobility inhibition was observed in the 100 mg/L group (0.00223 mg/L: measured concentration).

Reference substance (positive control):

yes

Remarks:

potassium dichromate (reagent grade)

Duration:

21 d

Dose descriptor:

NOELR

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

reproduction

Remarks:

cumulative number of juveniles produced per adult alive

Duration:

21 d

Dose descriptor:

NOELR

Effect conc.:

> 39.8 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Remarks:

refers to N N'-ethylene-bis-octadecanamide

Basis for effect:

reproduction

Remarks:

cumulative number of juveniles produced per adult alive

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

> 0.006 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks:

cumulative number of juveniles produced per adult alive

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

> 0.002 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

act. ingr.

Remarks:

refers to N N'-ethylene-bis-octadecanamide

Basis for effect:

reproduction

Remarks:

cumulative number of juveniles produced per adult alive

Details on results:

- Mortality of parent animals: no mortality was observed
- Mean cumulative no. of offspring produced per female for 21 days: control: 119.6, 0.00564 mg/L: 123.7
- Number of males and females (parental): 10 females in each group
- Time to first brood release or time to hatch: control: 8 days, 0.00564 mg/L: 8 days

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: EC50 for immobilisation: 0.75 mg/L

Reported statistics and error estimates:

LC50 and EC50 value and its 95% confidence limits could not be determined by statistical method because the mortality of parental Daphnia and the reproduction inhibition rate at the maximum concentration level was less than 50%. Welch's paired comparison test was applied for NOEC.

Table 1. Measured concentration of the test substance in test water duting a 21- day exposure period

Loading rate (mg/L)		Measured concentration (mg/L)						-
	Date	8 new	9 old	14 new	15 old	20 new	21 old	TWM
Control		<0.0002	<0.0002	<0.0002	<0.0002	<0.0002	<0.0002	-
100		0.00369	0.00338	0.00931	0.00508	0.00963	0.00828	0.00564

new: freshly prepared test solution

old: old test solution before renewal

TWM: time-weighted mean mesured concentration during 21 days

Table 2: Validity criteria for OECD 211.

Criterion from the guideline	Outcome	Validity criterion fulfilled
The mortality of the parent animals in the control (femaleDaphnia) does not exceed 20% at the end of the test.	0%	yes
The mean number of living offspring produced per parent animalsurvivingat the end of the test is ≥ 60 in the control.	119.6	yes

 

Validity criteria fulfilled:

yes

Remarks:

Please refer to table 2 in section "Any other information on results incl. tables"

Description of key information

The substance is not chronically toxic to aquatic invertebrates.

Additional information

The chronic toxicity of the substance to Daphnia magna was investigated in a study conducted according to OECD Guideline 211. The study was set up as a semi-static limit test with a nominal loading rate of 100 mg/L (WAF). The test solutions were renewed daily. Analytical dose verification by LC/MS performed with fresh and aged test medium resulted in a measured concentration of 0.00564 mg/L (time-weighted mean). During the exposure period of 21 days no mortalities of parent animals were observed. An effect on the reproduction rate of D. magna was not determined. Therefore, a NOEC (21 d) > 0.0056 mg/L (time-weighted mean) based on the reproduction rate was recorded.

Based on the available study results, the substance is not considered to be chronically toxic to aquatic invertebrates.