Reactionmass of dodecan-2-yl prop-2-enoate and dodecan-3-yl prop-2-enoate and dodecan-4-yl prop-2-enoate

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24th-27th September, 2019

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 3M FMRD, CPDC lot 6
- Expiration date of the lot/batch: 09/27/2021
- Purity: 99.1 wt %
- Storage condition of test material: In the sample chamber of this facility, stored at room temperature (15-25 °C).
- Stability under test conditions: Unstable
- Physical state: Clear colorless liquid.

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 mg/L (blank control) and 100 mg/L (nominal)
- Sampling method: For determination of test item concentrations in the static test, samples were taken from test group and control group of test media in 0, 24, 48 and 72 hour. The sample was taken from the leftover test solution for fresh samples and from one replicate for old samples. 10 mL of the sample was pretreated before analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Preparation of the test solutions started with the highest concentration of 100 mg/L, applying a 24 hour period of magnetic stirring ( 200 rpm) to attempt dissolution of the test item in medium. The test item was allowed to separate to the surface of solution for about 30 minutes, and the test solution on the bottom was taken to use for exposure.
- Controls: Test medium without test substance or other additives.

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Source: CTI-CSERC (Suzhou) CO., LTD
- Age of inoculum: Not reported
- Method of cultivation: propagation under same conditions as test.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test temperature:

22.9-23.2 °C

pH:

7.38-8.18

Nominal and measured concentrations:

See Table 1

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL, glass conical flasks, 100 mL fill volume
- Aeration: Shaking at 150 PRM
- Renewal rate of test solution: None
- Initial cells density: 5000 cell/mL
- Control end cells density: 325000 cell/mL
- No. of vessels per concentration (replicates): six
- No. of vessels per control (replicates): six

GROWTH MEDIUM
- Standard medium used: yes, OECD medium

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: no
- Photoperiod: continuous
- Light intensity and quality: 4440-8880 Lux, cool white light

EFFECT PARAMETERS MEASURED :
- Determination of cell concentrations: Manual cell counting with a microscope daily
- Other: abnormal cells also determined daily by microscopy, pH measured at beginning and end of test, light intensity measured daily with five points at test vessel level, temperature continuously monitored.


TEST CONCENTRATIONS
- Range finding study: Yes
- Test concentrations: 0 mg/L (blank), 100 mg/L (nominal)
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

no

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 0.024 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: No effect at only concentration tested.

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.024 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

- Exponential growth in the control: No
- Observation of abnormalities: no abnormalities
- Any stimulation of growth found in any treatment: no
- Effect concentrations exceeding solubility of substance in test medium: yes

Reported statistics and error estimates:

-% inhibition in test sample growth rate: 2.1% (P=0.051)
-% inhibition in test sample yield: 7.4% (P=0.058)
- Significance calculated as two-tailed T-test
- Mean coefficient of variation for section-by-section specific growth rates in the control cultures: 35%
- Coefficient of variation of average specific growth rates: 1.5%

Table 2. Cell counts from definitive test

Mean concentration (mg/L)	Replicate	0h (x10^4 cell/mL)	24 hour	48 hour	72 hour
Blank Control	1	0.5	2.0	14.5	33.0
	2	0.5	1.8	12.3	32.5
	3	0.5	1.8	11.5	33.0
	4	0.5	1.8	13.5	35.8
	5	0.5	2.0	13.5	29.5
	6	0.5	2.3	12.8	34.3
100	1	0.5	2.0	12.5	28.5
	2	0.5	2.3	11.5	32.5
	3	0.5	2.3	13.3	32.0
	4	0.5	2.3	14.5	28.3
	5	0.5	2.0	13.0	31.5
	6	0.5	2.0	12.3	30.8

Table 3. Growth rates (1/day) during the algae definitive test.

Mean concentration (mg/L)	T = 0-24 hour	T = 24-48 hour	T = 48-72 hour	T = 0-72 hour
Control	1.39	1.98	0.82	1.40
	1.28	1.92	0.97	1.39
	1.28	1.85	1.05	1.40
	1.28	2.01	0.98	1.42
	1.39	1.91	0.78	1.36
	1.53	1.72	0.99	1.41
Mean	1.36	1.90	0.93	1.40
SD	7.3%	5.5%	11%	1.5%
100	1.39	1.83	0.82	1.35
	1.53	1.61	1.04	1.39
	1.53	1.75	0.88	1.39
	1.53	1.84	0.67	1.35
	1.39	1.87	0.89	1.38
	1.39	1.82	0.92	1.37
Mean	1.46	1.79	0.87	1.37
SD	5.3%	5.3%	14%	1.3%

 

Validity criteria fulfilled:

yes

Remarks:

control biomass increase >16 (65x), CV for section-by-section growth rates ≤35% (35%), CV for average growth rates <7 (1.5%).

Conclusions:

72 hour EC50 > 100 mg/L (nominal) in Pseudokichneriella subcapitata (OECD 201).
72 hour EC50 > 0.024 mg/L (measured) in Pseudokichneriella subcapitata (OECD 201).

72 hour NOEC > 100 mg/L (nominal) in Pseudokichneriella subcapitata (OECD 201).
72 hour NOEC > 0.024 mg/L (measured) in Pseudokichneriella subcapitata (OECD 201).

Executive summary:

The 72 hour EC50 to Pseudokichneriella subcapitata was determined in a limit test according to OECD 201 guidelines. Nominal concentrations of 100 mg/L and a blank control were run using 6 replicates per concentration and no dispersant. Measured geometric mean concentrations of the substance during the test were 0.024 mg/L. No impairment of growth rate nor abnormal cells were observed throughout the test when compared to the control. An EC50 >100 mg/L (nominal concentration) and EC50 > 0.024 mg/L (measured) was determined. As well as a NOEC of >100 mg/L (nominal concentrations) and NOEC > 0.024 mg/L (measured).

Study was conducted under international guidelines and was compliant with GLP criteria. Test substance concentrations were not maintained at >=80% of the initial concentration at later timepoints. As there is no practical way to renew test solution in an algae growth inhibtion test, the available study result is the best possible outcome when utilizing this method..Therefore, this study is considered reliable with restrictions. The result is considered suitable for use in Risk Assessment, Classification & Labeling, and PBT analysis.

Description of key information

72 hour EC50 > 100 mg/L (nominal) in Pseudokichneriella subcapitata (OECD 201).

72 hour EC50 > 0.024 mg/L (measured) in Pseudokichneriella subcapitata (OECD 201).

72 hour NOEC > 100 mg/L (nominal) in Pseudokichneriella subcapitata (OECD 201).

72 hour NOEC > 0.024 mg/L (measured) in Pseudokichneriella subcapitata (OECD 201).

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L

EC10 or NOEC for freshwater algae:

100 mg/L

Additional information

The 72 hour EC50 to Pseudokichneriella subcapitata was determined in a limit test according to OECD 201 guidelines. Nominal concentrations of 100 mg/L and a blank control were run using 6 replicates per concentration and no dispersant. Measured geometric mean concentrations of the substance during the test were 0.024 mg/L. No impairment of growth rate nor abnormal cells were observed throughout the test when compared to the control. An EC50 >100 mg/L (nominal concentration) and EC50 > 0.024 mg/L (measured) were determined. A NOEC of >100 mg/L (nominal concentrations) and NOEC > 0.024 mg/L (measured) were also determined.

Study was conducted under international guidelines and was compliant with GLP criteria. Test substance concentrations were not maintained at >=80% of the initial concentration at later timepoints. As there is no practical way to renew test solution in an algae growth inhibition test, the available study result is the best possible outcome when utilizing this method. Therefore, this study is considered reliable with restrictions. The result is considered suitable for use in Risk Assessment, Classification & Labeling, and PBT analysis.