N-[3-(dimethylamino)propyl]dodecanamide N-oxide

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 Jan - 28. Feb 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

Adopted April 13, 2004

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

N-[3-(dimethylamino)propyl]dodecanamide N-oxide

EC Number:

263-218-7

EC Name:

N-[3-(dimethylamino)propyl]dodecanamide N-oxide

Cas Number:

61792-31-2

Molecular formula:

C17H36N2O2

IUPAC Name:

N-[3-(dimethylamino)propyl]dodecanamide N-oxide

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Control and the following test item concentrations: 32; 56 and 100 mg/L
- Sampling method: Single samples (2 mL) were taken after 0 and 48 h
- Sample storage conditions before analysis: Test samples were stored in the freezer (≤ -15°C).

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Preparation of test solutions started with the highest concentration of 100 mg/L (i.e. 340 mg test item/L) applying approximately 3 to 3¼ hours of magnetic stirring to completely dissolve the test item in test medium. Lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium. All test solutions were clear and colorless at the end of the preparation procedure. Note that the appearance of the highest test concentration was not recorded directly after preparation.
- Controls: Medium without test item
- Evidence of undissolved material: No, during the test period it was clear and colourless

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone: Straus
- Age at study initiation (mean and range, SD): Daphnia, less than 24 hours old
- Method of breeding: Approx. 250 newborn daphnids in 5 L of medium, after 7 days half of the medium was renewed, daily feeding, max age of cultures: 4weeks, Temp: 18-22 °C, Culture medium: M7
- Source: In-house laboratory culture with a known history
- Age of parental stock: More than two weeks old, at least third generation, obtained by a cyclical parthenogenesis under specified breeding conditions
- Feeding during test : No

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES, INCLUDING CULTURING CONDITIONS: Daphnia, less than 24 hours old, from parental daphnids of more than two weeks old.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

180 mg/L (CaCO3)

Test temperature:

20 - 21 °C

pH:

8.0 - 8.1 (Control)
7.8 - 8.1 (Test item concentrations)

Dissolved oxygen:

8.9 - 9.6 mg/L (Control)
7.4 - 9.7 mg/L (Test item concentrations)

Nominal and measured concentrations:

Control, 10, 18, 32, 56 and 100 mg/L (nominal)
Since the measured test item cocnentration were within a range of 80 to 120% of nominal the toxicological endpoints were evaluted based on the nominal test item concentrations.
The measured test item concentrations were determined at test end (48h): 33.4 (32), 63.4 (56) and 107 (100) mg/L (nominal test item concentrations).

Details on test conditions:

TEST SYSTEM
Test vessel:
- Type: open
- Material, size, headspace, fill volume: 60 mL all-glass test vessels, 10 mL headspace
- Volume of solution: 50 mL of test solution
- No. of organisms per vessel: 5 daphnids per vessel, 20 per test group
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: At least 2 mL of test solution per daphnid

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Tap water purified by Reverse Osmosis (RO-water, GEON Waterbehandeling, Berkel-Enschot, The Netherlands), additionally following salts were added (analytical grade):
CaCl2 x 2H2O: 211.5 mg/L; MgSO4x7H2O: 88.8 mg/L; NaHCO3: 46.7 mg/L; KCl: 4.2 mg/L
- Culture medium different from test medium: Yes
- Intervals of water quality measurement: pH and oxygen concentration were measured at test start and test end

OTHER TEST CONDITIONS
- Photoperiod: 16 h

EFFECT PARAMETERS MEASURED: Immobility

RANGE-FINDING STUDY
- Test concentrations: Control, 0.1; 1.0; 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: No immobility was observed in the control and at the three lowest test concentrations throughout the test period. Complete immobility was found at the highest test concentration after 48 h.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

71 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95%-confidence interval

Remarks:

65 - 76

Details on results:

- Immobilisation of control: No immobility was observed in the control

Reported statistics and error estimates:

The 48h-EC50 value was calculated by applying the Spearman-Karber procedure (non-linear; without trimming) on the percentages of affected daphnids and the logarithms of the corresponding nominal test item concentrations. ToxRat Professional v 3.2.1 (ToxRat Solutions® GmbH, Germany) was used to perform the analyses.

Any other information on results incl. tables

Biological Result

Tabe 1: Number of Introduced Daphnids and Incidence of Immobility in the Final Test 

Time (h)	Replicate	N-[3-(dimethyloxidoamino)propyl]-dodecanamide Nominal concentration (mg/L)
		Control	10	18	32	56	100
0	A	5	5	5	5	5	5
	B	5	5	5	5	5	5
	C	5	5	5	5	5	5
	D	5	5	5	5	5	5
Total introduced		20	20	20	20	20	20
24	A	0	0	0	0	1	5
	B	0	0	0	0	0	4
	C	0	0	0	0	0	5
	D	0	0	0	0	1	4
Total immobilised		0	0	0	0	2	18
Effect %		0	0	0	0	10	90
48	A	0	0	0	0	1	5
	B	0	0	0	0	0	5
	C	0	0	0	0	0	5
	D	0	0	0	0	1	5
Total immobilised		0	0	0	0	2	20
Effect %		0	0	0	0	10	100

Analytical Results:

Samples taken from the nominal concentrations of 32, 56 and 100 mg/L showed that the measured concentrations were in agreement with nominal at the start of the test, i.e. were 109 -113%, and remained stable during the test period, i.e. were 104-113% of nominal at the end of the test. Small test item responses were detected in the control samples. The maximum contribution to the 32 mg/L sample ranged between 0.0012 and 0.00054%. Therefore, the contribution was not considered to affect the study results.

In view of these results, effect parameters were expressed in terms of analytically confirmed nominal concentrations.

Table 2: Validity criteria

Criterion from the guideline	Outcome	Validity criterion fulfilled
In the control, including the control containing the solubilising agent, not more than 10% of the daphnids should have been immobilized.	0	Yes
The dissolved oxygen concentration at the end of the test should be ≥ 3 mg/L in control and test vessels.	7.4 – 8.9 mg/L	Yes

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

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