N-[3-(dimethylamino)propyl]stearamide monoacetate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015-02-02 to 2015-07-23

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)

Version / remarks:

2004

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Samples were collected at 0, 24 and 48 hours from all test concentrations (0.05, 0.10, 0.20. 0.40 and 0.80 mg/L) and control.

Details on test solutions:

Method: ultrasonication of stock solution (0.1053 g test substance added to 100 mL deionised water).
Stock solution was then diluted with Elendt MT to the appropriate test concentrations.

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna, not from the first brood progeny, were less than 24 hours old at the start of the test.
Stock animals were maintained in Elendt M7 medium under similar conditions to test conditions.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

Not reported

Test temperature:

20.5 - 21.2 degrees Celsius

pH:

7.10 - 7.82

Dissolved oxygen:

92-100 %

Salinity:

NA

Nominal and measured concentrations:

The nominal concentrations were 0.05, 0.10, 0.20, 0.40 and 0.80 mg/L, the respective measured concentrations were in ranges 0.040-0.041, 0.083 - 0.087, 0.165-0.169, 0.341-0.353 and 0.890-0.928 mg/L. These were within 20% of the nominal concentrations.

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers
- Material, size, headspace, fill volume:100 mL, 50 mL test solution in each vessel
- Aeration: none
- Renewal rate of test solution (frequency/flow rate): NA
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4


TEST MEDIUM / WATER PARAMETERS
- Elendt M7
- Culture medium different from test medium:No


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: Complete darkness

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobility measured at 24 and 48 h.

RANGE-FINDING STUDY
- Test concentrations: 0.10, 1.01, 10.1 mg/L nominal concentrations
- Results used to determine the conditions for the definitive study: NS

Reference substance (positive control):

yes

Remarks:

Potassium dichromate, purity >99.8 %, Lot number: 13012220054

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.29 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The results can be seen in Table 1 in the "Any other information on results incl. tables" section

- Behavioural abnormalities: not reported
- Observations on body length and weight: not reported
- Other biological observations: not reported
- Mortality of control: not reported
- Other adverse effects control: not reported
- Abnormal responses: not reported
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: not reported
- Effect concentrations exceeding solubility of substance in test medium: not reported

Results with reference substance (positive control):

Potassium dichromate 24 h EC50 was 1.13 mg/L

Reported statistics and error estimates:

EC50 and 95% confidence limits were calculated by Trimmed Spearman-Karber Method (Version 1.5, USEPA)

Table 1. Acute Immobilization of Test Substance on Daphnia magna during the Definitive Test

Nominal Conc. (mg/l)	Measured Conc. (mg/L)	Initial number of Daphnids	24 h		48 h
			Number of immobilised Daphnids	Immobilisation rate (%)	Number of Immobilised Daphnids	Immobilisation rate (%)
Control	ND	5	0	0	0	0
		5	0		0
		5	0		0
		5	0		0
0.05	0.04	5	0	0	0	0
		5	0		0
		5	0		0
		5	0		0
0.10	0.083	5	0	0	0	10
		5	0		0
		5	0		1
		5	0		1
0.20	0.167	5	0	10	1	30
		5	0		1
		5	1		2
		5	1		2
0.40	0.347	5	2	30	2	55
		5	2		3
		5	1		3
		5	1		3
0.80	0.909	5	5	100	5	100
		5	5		5
		5	5		5
		5	5		5
EC50 (mg/L based on the nominal concentration)			0.43		0.29
95% confidence interval (mg/L, based on nominal concentrations)			0.40 – 0.46		0.26 – 0.32

Validity criteria fulfilled:

yes

Remarks:

None of the control Daphnids were immobilised, the dissolved oxygen concentrations varied between 92 and 100 % of air concentrations

Conclusions:

The effects of the substance were assessed under static test conditions on Daphnia magna according to OECD Guideline 202. The 48 h EC50 for the test substance was 0.29 mg/L based on nominal concentrations (95% confidence limit based on measured concentrations was 0.26 - 0.32 mg/L). 

Executive summary:

This test was carried out according to "The guidelines for the testing of Chemicals-Effects on Biotic Systems" (2nd edition, Beijing: China Environment Press, 2013) and with reference to procedure 202 of the "Guidelines for Testing of Chemicals" ("Daphnia sp., acute immobilisation test" (2004)) according to GLP. In it Daphnia magna were exposed to the test substance for 48 hours to nominal concentrations of 0.05, 0.10, 0.20, 0.40 and 0.80 mg/L. 20 daphnids were used for each exposure (4 replicates, 5 Daphnids in each). Immobilisation was estimated at 24 and 48 hours from the beginning of the experiment. 

During the test, pH values varied between 7.10 and 7.82 and dissolved oxygen values varied between 92 and 100 %, the temperature varied between 20.5 and 21.2 degrees Celsius. The amounts of the test substance were measured using HPLC-MS from samples collected at the beginning and at the end of the experiment and the resulting amounts were within 20% of the nominal concentrations. 

A toxic control experiment was carried out using K₂Cr₂O₇ with the resulting 24 h EC₅₀ of 1.13 mg/L. 

There was no immobilisation observed at the control and 0.05 mg/L treatments, but all Daphnids were immobilised at the 0.80 mg/L concentration after 24 hours. The resulting 48 h EC50 for the test substance was 0.29 mg/L based on nominal concentrations (95% confidence limit based on measured concentrations was 0.26-0.32 mg/L). 

 

 

 

Description of key information

48 h EC50 = 0.29 mg/L (Daphnia magna); OECD 202; Zhen (2015)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

0.29 mg/L

Additional information

The key study for this endpoint was carried out according to "The guidelines for the testing of Chemicals-Effects on Biotic Systems" (2nd edition, Beijing: China Environment Press, 2013) and with reference to procedure 202 of the "Guidelines for Testing of Chemicals" ("Daphnia sp., acute immobilisation test" (2004)) according to GLP. In it Daphnia magna were exposed to the test substance for 48 hours to nominal concentrations of 0.05, 0.10, 0.20, 0.40 and 0.80 mg/L. 20 daphnids were used for each exposure (4 replicates, 5 Daphnids in each). Immobilisation was estimated at 24 and 48 hours from the beginning of the experiment. 

During the test, pH values varied between 7.10 and 7.82 and dissolved oxygen values varied between 92 and 100 %, the temperature varied between 20.5 and 21.2 degrees Celsius. The amounts of the test substance were measured using HPLC-MS from samples collected at the beginning and at the end of the experiment and the resulting amounts were within 20% of the nominal concentrations. 

A toxic control experiment was carried out using K₂Cr₂O₇ with the resulting 24 h EC₅₀ of 1.13 mg/L. 

There was no immobilisation observed at the control and 0.05 mg/L treatments, but all Daphnids were immobilised at the 0.80 mg/L concentration after 24 hours. The resulting 48 h EC50 for the test substance was 0.29 mg/L based on nominal concentrations (95% confidence limit based on measured concentrations was 0.26-0.32 mg/L).