1-Propanaminium, 2-hydroxy-N-(2-hydroxypropyl)-N,N-dimethyl-, esters with fatty acids, C16-18 (even numbered) and C18 unsatd., Me sulfates (salts)

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:

2013-05-22 to 2013-06-12

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:

13 April 2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Qualifier:

according to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

Version / remarks:

Third edition, 1996-04-01

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Name of test material (as cited in study report): 1-Propanaminium, 2-hydroxy-N-(2-hydroxypropyl)-N,N-dimethyl-, esters with fatty acids, C16-18 (even numbered), C18 (unsatd.), Me sulfates (salts)

Analytical monitoring:

yes

Details on sampling:

Frequency: At the start and the end of both refreshment periods.
Volume: 2 mL from the approximate centre of the test vessels
Storage: Samples were stored in a freezer until analysis.
At the end of each refreshment period, the replicates were pooled at each concentration before sampling.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
For the preparation of test solutions test medium (IHSS Suwannee River, USA) was preheated to approximately 60°C. Into this medium 25 mg of MDIPA-Esterquat C16-18 and C18 unsatd. (55°C - 60°C) was added in small amounts. After the dosage the stirring was continued for a further 5 to 10 minutes. Thereafter, the dispersion was left to cool down to room temperature. The lower test concentrations were prepared by subsequent dilutions of the 25 mg/L concentration in test medium. All test vessels were pre-incubated for 30 minutes with the respective test solution before the start of the test.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain: Straus, 1820
- Source: In-house laboratory culture with a known history
- Age at study initiation (mean and range, SD): <24 h
- Method of breeding:
Start of each batch: newborn daphnids, i.e. less than 3 days old, by placing about 250 of them into 5 litres of medium in an all-glass culture vessel.
Maximum age of the cultures: 4 weeks
Renewal of the cultures: After 7 days of cultivation half of the medium twice a week.
Temperature of medium: 18-22°C
Feeding: Daily, a suspension of fresh water algae.
Medium: M7, as prescribed by Dr. Elendt-Schneider
- Feeding during test: no

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

180 mg/L expressed as CaCO3

Test temperature:

19.5 - 20.2 °C

pH:

fresh media: 7.8
24/48 h old media: 7.9-8.0

Dissolved oxygen:

fresh media: 7.5 - 9.0 mg/L
24/48 h old media: 8.3 - 8.9 mg/L

Nominal and measured concentrations:

nominal: 0, 2.5, 4.5, 8.1, 14 and 25 mg/L + 4 mg/L humic acid (2 mg/L DOC), corresponding to measured concentrations of 2.73, 2.87 (fresh), 2.59,2.73 (old); 4.91, 5.29 (fresh) 4.86, 5.07 (old); 8.75, 9.21 (fresh), 8.73, 8.97 (old); 15.3, 15.9 (fresh) 13.4, 14.1 (old); 28.3, 28.7 (fresh) 24.3, 25.7 (old) mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL, all-glass, containing 80 ml of test solution
- Aeration: no
- Renewal rate of test solution (frequency/flow rate): renewal of test solutions after 24 h
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Adjusted ISO medium, with 4 mg humic acid per litre, water from IHSS Suwannee River
- Total organic carbon: 2 mg/L (measured for control: <2.0 mg/L)

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light
- Light intensity: no data

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Immobility (including mortality): at 24 and at 48 h
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 medium: continuously in a temperature control vessel, beginning at the start of the test

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
- Range finding study
The test concentrations used for final test were based on the results of preceding screening tests with Daphnia magna.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

6.7 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks on result:

other: 5.8 - 8.0

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

13 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks on result:

other: 11 - 16

Details on results:

- Behavioural abnormalities: no
- Mortality of control: 0
- Other adverse effects control: no
- Abnormal responses: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: nominal concentration analytically confirmed
- Effect concentrations exceeding solubility of substance in test medium

Results with reference substance (positive control):

- Results with reference substance valid? yes
- 48 h EC50=0.53 mg/L, 95% confidence interval 0.49 - 0.62 mg/L; valid range: 0.49 - 0.62 mg/L

Reported statistics and error estimates:

48h-EC50 = 6.65 mg/L
95 % fiducial limits: 5.83 - 7.97 mg/L
index of regression significance: g=0.02
chi-squared=11.68, with 18 degrees of freedom
regression line: log10(conc.)=0.40+(probit-3.10)/4.49

Analysis of the samples taken at the start of both refreshment periods showed that measured concentrations were in agreement with nominal (108-117%). These concentrations remained stable during the following 24 hours (84-103% of initial at the end of both refreshment periods). Given these results, effect parameters were based on the nominal concentrations.

 

At the start of both refreshment periods measured DOC concentrations ranged between 1.0 and 3.5 mg/L for all concentrations up to and including 14 mg/L. These concentrations remained stable during the refreshment period. Measured DOC at 25 mg/L was 11 mg/L at the start of both refreshment periods and decreased to 8.6/8.7 mg/L at the end of the refreshment periods.

Acute immobilisation of daphnids after 24 and 48 hours in the final test

Nominal conc. MDIPA-Esterquat C16-18 and C18 unsatd. (mg/l)	Vessel number	Number Daphnia exposed	Response at 24 h		Response at 48 h
			number	Total %	number	Total %
control	A B C D	5 5 5 5	0 0 0 0	0	0 0 0 0	0
2.5^1	A B C D	5 5 5 5	0 0 0 0	0	0 0 0 0	0
4.5^1	A B C D	5 5 5 5	0 0 0 0	0	2 0 2 2	30
8.1^1	A B C D	5 5 5 5	1 0 1 0	10	4 3 3 1	55
14^2	A B C D	5 5 5 5	2 3 3 1	45	4^4 5^4 5^4 5^4	95
25^3	A B C D	5 5 5 5	5 5 5 5	100	5 5 5 5	100

¹Clear yellow solution

²Very slightly hazy yellow solution

³Slightly hazy yellow solution

⁴A test substance precipitate was observed

Concentrations of the test substance in test medium - final test

Time of sampling [hours]	Date of sampling	Date of analysis^1	Concentration		Relative to nominal [%]	Relative to initial [%]
			Nominal [mg/l]	Analysed [mg/l]
0	10-Jun-2013	14-Jun-2013	0	n.d.	n.a.
(fresh)			2.5	2.87	115
			4.5	5.29	117
			8.1	9.21	114
			14	15.9	114
			25	28.3	113
24	11-Jun-2013	14-Jun-2013	0	n.d.	n.a.	n.a.
(old)			2.5	2.59	104	90
			4.5	4.86	108	92
			8.1	8.97	111	97
			14	13.4	96	84
			25	24.3	97	86
24	11-Jun-2013	14-Jun-2013	0	n.d.	n.a.
(fresh)			2.5	2.73	109
			4.5	4.91	109
			8.1	8.75	108
			14	15.3	109
			25	28.7	115
48	12-Jun-2013	14-Jun-2013	0	n.d.	n.a.	n.a.
(old)			2.5	2.73	109	100
			4.5	5.07	113	103
			8.1	8.73	108	100
			14	14.1	101	92
			25	25.7	103	90

n.d.       Not detected. The limit of detection of the method was determined to be 0.0002 mg/l taking a dilution factor of two into account. The small signal observed is probably caused by carry over since a similar response was observed in the analytical blank.

n.a.       Not applicable.

 

Validity criteria fulfilled:

yes

Conclusions:

The 48h-EC50 of MDIPA-Esterquat C16-18 and C18 unsatd. was 6.7 mg/L in ISO medium containing 4 mg humic acid per litre. The 95% confidence interval was between 5.8 and 8.0 mg/L.

Executive summary:

The 48–hr-acute toxicity of MDIPA-Esterquat C16-18 and C18 unsatd. to Daphnia magna was studied under semi-static conditions.  Daphnids were exposed to control and test chemical at analytically confirmed nominal concentrations of 0, 2.5, 4.5, 8.1, 14 and 25 mg/L in the presence of 4 mg/L (< 2mg/L DOC) humic acid for 48 h.  Immobilisation was observed daily. 

The 48-hour EC50 was 6.7 mg/L (analytically confirmed nominal concentration) based on immobilisation.  

 

Results Synopsis

Test Organism Age: Daphnia magna, <24 h

Test Type: semi-static renewal

 

48h-EC50: 6.7 mg a.i./L

Endpoint(s) Effected:  immobilisation

Description of key information

48 h EC50 6.7 mg a.i./L (nominal, analytically confirmed) (Daphnia magna); OECD guideline 202, GLP, RL1; in the presence of 4 mg/L humic acid

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

6.7 mg/L

Additional information

The 48–hr-acute toxicity of MDIPA-Esterquat C16-18 and C18 unsatd. to Daphnia magna was studied under semi-static conditions. Daphnids (<24 h) were exposed to control and test chemical at analytically confirmed nominal concentrations of 0, 2.5, 4.5, 8.1, 14 and 25 mg/L in the presence of 4 mg/L (< 2 mg/L DOC) humic acid for 48 h.  Immobilisation was observed daily. 

The 48-hour EC50 was 6.7 mg/L (analytically confirmed nominal concentration) based on immobilisation.  

In a supporting study, the 48 hr-acute toxicity of MDIPA-Esterquat C16-18 and C18 unsatd. to Daphnia magna was studied under semi-static conditions.  Daphnids were exposed to control and test chemical at nominal concentrations of 0, 2.5, 4.5, 8.1, 14 and 25 mg/L in the presence of 4 mg/L (< 2 mg/L TOC) humic acid for 48 h.  Immobilisation was observed daily. 

The 48-hour EC50 was 13.69 (12.03 - 15.58) mg/L (nominal concentration) based on immobilisation.  

 

Similar results were obtained with the closely related read-across substance MDEA-Esterquat C16-18 and C18 unsatd.: 

The 24-hr acute toxicity of MDEA-Esterquat C16-18 and C18 unsatd. to Daphnia magna was investigated under static conditions in a study conducted according to OECD TG 202 (Part I). Daphnids were exposed to 0, 0.1, 0.32, 1.0, 3.2, 10 and 32 mg/L (nominal) for 24 hours. Immobilisation was observed at test termination. The 24-h EC50 was 14.8 mg/L with 95% CL of 8.4 - 26.2 mg/L (nominal each). No other effects were noted. The study period of 24 h was recommended before adoption of the OECD Guideline 202 in 2004. Therefore this study does not meet the time criterium (study duration 24 h instead of 48 h) of today standard methods.