Reaction mass of 2,2'-[(4-methylphenyl)imino]bisethanol and Ethanol, 2-[[2-(2-hydroxyethoxy)ethyl](4-methylphenyl)amino]-

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:

4th - 27th February, 2013

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)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

(2008)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: ISO International Standard 6341: "Water quality - Determination of the inhibition of the mobility of Daphnia magna Straus - Acute toxicity test (1996)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations sampled for analysis
Range-finding test: 10 mg/L
Final test: 0 (blank-control), 32, 56 and 100 mg/L
- Sampling
Frequency: at t=0 h and t=48 h
Volume: 2 ml

- Sample storage conditions before analysis: Samples were stored in a freezer until analysis (≤ -15°C). On the day of analysis, the samples were defrosted at room temperature. If necessary, the samples were diluted with ISO-medium to obtain concentrations within the calibration range.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The preparation of test solutions started with the highest test concentration. No special treatment other than a short magnetic stirring period was applied to fully dissolve the test substance in test medium. The lower test concentrations were prepared by subsequent dilutions in test medium.
- Controls: blank control (test medium without test substance or other additives)
- Evidence of undissolved material: The final test solutions were all clear and colourless.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: In-house laboratory culture with a known history (at least third generation, obtained by acyclical parthenogenesis under specified breeding conditions)
- Age at study initiation: <24 h
- Method of breeding: 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. Each batch was started with newborn daphnids, i.e. less than 3 days old. M7 medium (according to: Elendt, B.-P., 1990 Selenium deficiency in Crustacea. An ultrastructural approach to antennal damage in Daphnia magna Straus. Protoplasma 154, 25-33) was used. Maximum age of the cultures was 4 weeks.
- Type of food and feeding frequency during breeding: suspension of fresh water algae, feed daily.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

180 mg/L expressed as CaCO3

Test temperature:

- Final test:
At start temperature varied between 19.9 and 20.3°C
The temperature continuously measured during the test varied between 18.9 and 19.6°C

pH:

- Final test
At start: 7.9
At the end: 8.1

Dissolved oxygen:

- Final test (mg/L)
At start: 9.9
At the end: 9.2 - 9.3

Nominal and measured concentrations:

- Nominal
Range-finding test: 0 (blank-control), 0.1, 1, 10 and 100 mg/L
Final test: 0 (blank-control), 10, 18, 32, 56 and 100 mg/L

- Measured: See the "Remarks on results including figures and tables" field for details.

Details on test conditions:

TEST SYSTEM
- Test vessel: All-glass, with a capacity of 100 ml and filled with 80 ml of test solution
- Aeration: No
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates)
Range-finding test: 4 replicates for the 100 mg/L and 2 replicates for 0.1, 1.0 and 10 mg/L
Final test: 4 replicates
- No. of vessels per control (replicates):
Range-finding test: 4 replicates
Final test: 4 replicates

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: tap water purified by Reverse Osmosis
- Breeding medium: M7
- Test medium: Adjusted ISO medium
- Intervals of water quality measurement
Range-finding test: Dissolved oxygen concentrations and pH were only measured in the control and the highest test concentration

Final test:
pH and dissolved oxygen - At the beginning 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.

OTHER TEST CONDITIONS
- Photoperiod: 16 h light : 8 h dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Immobility (including mortality) at 24 and 48 h.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: approx. X1.8
- Range finding study
- Test concentrations: 0 (blank-control), 0.1, 1, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

yes

Remarks:

potassium dichromate (K2Cr2O7)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

48 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks:

(including mortality)

Remarks on result:

other: 95% CL: 27 to 75 mg/L

Details on results:

- Range-finding test: No immobility was observed at concentrations of 0.10, 1.0 and 10 mg/L. The immobility at the highest concentration was 90% after 48 hours. Therefore, the expected EC50 was between 10 and 100 mg/L.

- Final test: The responses recorded were in agreement with what was expected based on the results of the range-finding test. Accelerator (PT 25E or PT 25E/2) did not induce significant acute immobilisation of Daphnia magna at 32 mg/L after 48 hours of exposure (NOEC)
- Acceptability of the test:
1. In the control, no daphnids became immobilised.
2. The oxygen concentration at the end of the test was ≥ 3 mg/L in control and test vessels.

Results with reference substance (positive control):

Potassium dichromate (K2Cr2O7): The 48h-EC50 was 0.53 mg/L with a 95% confidence interval between 0.49 and 0.62 mg/L.

- Range-finding test

Measured concentrations:

Concentrations of the test substance in test medium in the range-finding 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]	Analysed corrected^2 [mg/L]
0	04 -Feb-2013	11 -Feb-2013	10	11.4	10.0	100
48	06 -Feb-2013	11 -Feb-2013	10	11.4	10.1	101	100

¹          Samples were stored in the freezer (≤ -15°C) until the day of analysis.

²          Corrected for the 113% mean recovery of all procedural recovery samples analysed in this series.

Biological results:

Incidence of immobility in the range-finding test

Concentration Accelerator (PT 25E or PT 25E/2) (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
0.1	A B	5 5	0 0	0	0 0	0
1.0	A B	5 5	0 0	0	0 0	0
10	A B	5 5	0 0	0	0 0	0
100	A B C D	5 5 5 5	3 2 1 1	35	5 4 5 4	90

- Final test

Measured concentrations:

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]	Analysed corrected^2 [mg/L]
0	25 -Feb-2013	04 -Mar-2013	0	n.d.	n.d.	n.a.
			32	37.4	33.6	105
			56	64.8	58.3	104
			100	116	104	104
48	27 -Feb-2013	04 -Mar-2013	0	n.d.	n.d.	n.a.
			32	37.4	33.6	105	100
			56	64.7	58.2	104	100
			100	116	104	104	100

¹          Samples were stored in the freezer (≤ -15°C) until the day of analysis.

²          Corrected for the 111% mean recovery of the 100 mg/l procedural recovery samples analysed in this series.

n.d.    Not detected.

n.a.     Not applicable.

Biological results:

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

Concentration Accelerator (PT 25E or PT 25E/2) (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 (2) 0 0	0
10	A  B C D	5 5 5 5	0 0 0 0	0	0 0 0 0	0
18	A  B C D	5 5 5 5	0 0 0 0	0	0 0 0 0	0
32	A  B C D	5 5 5 5	0 0 1 0 (1)	5	0 0 1 0	5
56	A  B C D	5 5 5 5	1 1 1 4	35	4 5 4 5	90
100	A  B C D	5 5 5 5	1 1 1 3	30	5 3 5 4	85

( ) between brackets: number of daphnia observed trapped at the surface of the test solutions. These organisms were reimmersed into the respective solutions before recording of mobility.

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the present study Accelerator (PT 25E or PT 25E/2) did not induce significant acute immobilisation of Daphnia magna at 32 mg/L after 48 hours of exposure (NOEC). The 48h-EC50 was 48 mg/L based on analytically confirmed nominal exposure concentrations (95% confidence interval between 27 and 75 mg/L).

Executive summary:

In a 48-h acute toxicity study conducted according to OECD guideline 202, water fleas (Daphia magna) were exposed to Accelerator (PT 25E or PT 25E/2) under static conditions at the following nominal concentrations: 0 (blank-control), 10, 18, 32, 56 and 100 mg/L. Accelerator (PT 25E or PT 25E/2) did not induce significant acute immobilisation of Daphnia magna at 32 mg/L after 48 hours of exposure. The 48h-EC50 was 48 mg/L based on analytically confirmed nominal exposure concentrations (95% confidence interval between 27 and 75 mg/L). The study is considered to be reliable without restrictions.

Description of key information

In a 48-h acute toxicity study conducted according to OECD guideline 202, water fleas (Daphia magna) were

exposed to Accelerator (PT 25E or PT 25E/2). The 48h-EC50 was 48 mg/L based on analytically confirmed

nominal exposure concentrations. The study is considered to be reliable without restrictions.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

48 mg/L

Additional information

In a 48-h acute toxicity study conducted according to OECD guideline 202, water fleas (Daphia magna) were exposed to Accelerator (PT 25E or PT 25E/2) under static conditions at the following nominal concentrations: 0 (blank-control), 10, 18, 32, 56 and 100 mg/L. Accelerator (PT 25E or PT 25E/2) did not induce significant acute immobilisation of Daphnia magna at 32 mg/L after 48 hours of exposure. The 48h-EC50 was 48 mg/L based on analytically confirmed nominal exposure concentrations (95% confidence interval between 27 and 75 mg/L). The study is considered to be reliable without restrictions.