1-Decanaminium, N-decyl-N,N-dimethyl-, hexanedioate (2:1)

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:

20 March 2017 - 04 May 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

13 April 2004

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Reference substance 001

Cas Number:

210420-85-2

Constituent 2

Reference substance name:

N-methyldidecylamine

EC Number:

230-990-1

EC Name:

N-methyldidecylamine

Cas Number:

7396-58-9

Molecular formula:

C21H45N

IUPAC Name:

N-decyl-N-methyldecan-1-amine

Constituent 3

Reference substance name:

Water

EC Number:

231-791-2

EC Name:

Water

Cas Number:

7732-18-5

Molecular formula:

H2O

IUPAC Name:

Dihydrogen oxide

impurity 1

Reference substance name:

Unknown impurities

Molecular formula:

Not available

IUPAC Name:

Unknown impurities

Test material form:

solid

Details on test material:

- Appearance: Slightly yellow gel
- Storage conditions: At room temperature; container flushed with nitrogen

Specific details on test material used for the study:

Correction for purity: 1.081
Solubility in water: > 1000 g/L

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Single samples for possible analysis were taken from all test concentrations and the control according to the schedule below.
Frequency at t=0 h and t=48 h
Volume 2.0 mL from the approximate centre of the test vessels
Storage Samples were stored in a freezer (=-15°C) until analysis at the analytical laboratory of the Test Facility.
At the end of the exposure period, the replicates were pooled at each concentration before sampling.

No samples for analysis were taken from the control in the range-finding test.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION:
- Correction for purity: A correction factor of 1.081 for purity was applied (reported concentrations represent corrected values).
- Method: Direct application to test medium.
Preparation of test solutions started with 100 mg/L (highest test concentration in combined limit/range-finding) or 10 mg/L (range-finding and final test) applying a one to two-hour period of low-speed magnetic stirring to accelerate dissolution of the test item in medium and to prevent possible micelle formation. Lower test concentrations were prepared by subsequent dilutions in test medium. All test solutions were clear and colorless at the end of the preparation procedure.
Test solutions were prepared twice for each experiment. The first volume was used to pre-incubate the test vessels for one day as to minimize any possible adsorption of the test item to the glass surfaces.
- Controls: Test medium without test item or other additives.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain: Straus, 1820
- Source: in-house laboratory culture with a known history. At least third generation, obtained by a cyclical parthenogenesis under specified breeding conditions.
- Age of parental stock: Daphnids originated from a healthy stock, 2nd to 5th brood, showing no signs of stress such as mortality >20%, presence of males, ephippia or discoloured animals and there was no delay in the production of the first brood.
- Age at study initiation: < 24 hours, from parental daphnids of more than two weeks old.
- Feeding during test: no

ACCLIMATION
- Acclimation period: no

BREEDING:
- Method: each batch was started with newborn daphnids, i.e. less than 3 days old, by placing about 250 of them into 5 litres of medium (M7) in an all-glass culture vessel. After 7 days of cultivation half of the medium was renewed twice a week.
- Feeding: daily, a suspension of fresh water algae.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

180 mg/L

Test temperature:

19.8-20.5 °C

pH:

7.9-8.0

Dissolved oxygen:

8.8-9.0 mg O2/L

Nominal and measured concentrations:

Nominal concentrations: 0.010, 0.018, 0.032, 0.056 and 0.10 mg/L
Geometric mean concentrations: 0.007, 0.015, 0.029, 0.056 and 0.11 mg/L, respectively corresponding to nominal concentrations above.
The test concentrations were based on measurement of two components (1-Decanaminium,N-decyl-N,N-dimethyl and Hexanedioate, which, according to the spectral data, represent 70.5% and 15.7% of the test item, resp.). Since the results based on Hexanedioate were nearly all below the limit of detection, the average measured concentration was calculated using only the measured concentrations of 1-Decanaminium,N-decyl-N,N-dimethyl.

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 ml, all-glass
- Fill volume: 80 mL, silanized and pre-incubated with test concentrations for 24 hours
- 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
- Standard medium used: yes, adjusted ISO medium
- Source/preparation of dilution water: tap water purified by reverse osmosis
- Culture medium different from test medium: yes, M7 was used as culture medium

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours, daily

EFFECT PARAMETERS MEASURED: mobility at 24 and 48 hours.
- Additional measurements: pH and dissolved oxygen at the beginning, after 24 hours of exposure and at the end of the test, for all concentrations and the control. Temperature of the medium: continuously in a temperature control vessel.

COMBINED LIMIT/RANGE-FINDING STUDY
- Test concentrations: 0.10, 1.0, 10 and 100 mg/L
- Results: since all daphnids became immobile, a range-finding test was conducted to determined the doses for the final test.

RANGE-FINDING STUDY
- Test concentrations: 0.0010, 0.010 and 0.10 mg/L
- Results used to determine the conditions for the definitive study: yes, the EC50 was expected to be between 0.010 and 0.10 mg/L.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (Feb 2017)

Results and discussion

Effect concentrations

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.035 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95%-CI: 0.030-0.060

Remarks:

Based on measured concentrations of 1-Decanaminium,N-decyl-N,N-dimethyl

Details on results:

- No biological, behavioural or other abnormalities were observed in the control group or any of the test concentrations.
- Analysis showed that test concentrations of Hexanedioate were nearly all below the detection limit. Estimated values for the three highest concentrations indicated that they were likely close to or at nominal. These results could however not be used to reliably calculate average exposure concentrations for the test item.
- Analysis based on 1-Decanaminium,N-decyl-N,N-dimethyl showed that test concentrations were in agreement with nominal at the start of the test but decreased to 52 - 93% of initial concentrations at t=48 h.
- Measured concentrations for the test substance were calculated according to spectral data (Meas. conc. 1-Decanaminium,N-decyl-N,N-dimethyl *100/70.5). From these values, the geometric mean concentrations were calculated which were used to determine the effect concentrations.
- Individual pH, temperature and dissolved oxygen values remained within acceptable limits throughout the duration of the study.

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- 48h-EC50: 0.48 mg/L, 95%-confidence interval: 0.43-0.53 mg/L
- Other: results fell within the historical range.

Reported statistics and error estimates:

The 24 and 48h-EC50-value was calculated from the weibits of the percentages of affected daphnids and the logarithms of the corresponding test item concentrations (average measured) using the maximum likelihood estimation method.

Any other information on results incl. tables

Table 1 Average exposure concentrations versus nominal concentrations

1-Decanaminium, N-decyl-N,N-dimethyl-, hexanedioate (2:1) Nominal concentration (mg/L)	Measured test item concentration^#(mg/L)		Average exposure (mg/L)
	t=0h	t=48h
0.010	0.010	0.0052	0.007
0.018	0.019	0.012	0.015
0.032	0.034	0.025	0.029
0.056	0.061	0.051	0.056
0.10	0.111	0.104	0.11

^#= Meas. conc.1-Decanaminium,N-decyl-N,N-dimethyl *100/70.5

Table 2 Number of Introduced Daphnids and Incidence of Immobility in the Final Test

Time (h)	Replicate	Average concentration 1-Decanaminium, N-decyl-N,N-dimethyl-, hexanedioate (2:1) (mg/L)
		Control	0.007	0.015	0.029	0.056	0.11
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	5	5
	B	0	0	0	0	5	5
	C	0	0	0	0	4	5
	D	0	0	0	0	5	5
	Total immobilised	0	0	0	0	19	20
	Effect %	0	0	0	0	95	100
48	A	0	0	0	1	5	5
	B	0	0	0	3	5	5
	C	0	0	0	0	5	5
	D	0	0	0	0	5	5
	Total immobilised	0	0	0	4	20	20
	Effect %	0	0	0	20	100	100

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

1). In the control, no daphnids became immobilised or showed other signs of disease or stress. 2). The oxygen concentration at the end of the test was = 3 mg/L in control and test vessels (e.g., =8.8 mg/L).

Conclusions:

The 48h-EC50 of 1-Decanaminium, N-decyl-N,N-dimethyl-, hexanedioate (2:1) towards Daphnia magna, was 0.035 mg/L based on geometric mean measured concentrations.