Coconut oil, reaction products with polyethylene glycol and trimethylolpropane

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:

1997

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

IDENTIFICATION AND QUANTIFICATION OF TEST SUBSTANCE/PRODUCT
- Detection method (e.g. ECD, UV, MS, ICP-AES, ICP-MS): TOC-infraredanalysator

Vehicle:

no

Details on test solutions:

stock solution 1 g/L in VE-water

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: Green algae
- Strain: Scenedesmus subspicatus (CHODAT (86.81 SAG))
- Source (laboratory, culture collection): Institut für Wasser-, Boden- und Lufthygiene, Berlin; subsequently in-house breeding
- Method of cultivation: in sterile-aerated Erlenmeyer flasks on light benches


ACCLIMATION
- Acclimation period: A preculture is withdrawn from a stock culture by tranfer 3 days prior to the beginning of the test from which preculture the test cultures are inoculated at a cell density of approximately 20 000 cells/mL.
- Culturing media and conditions (same as test or not): not mentioned
- Any deformed or abnormal cells observed: not mentioned

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

none

Hardness:

Growth/test medium chemistry as described in guideline 92/69/EEC (C.3.), no further details mentioned

Test temperature:

23.4 - 23.8 °C

pH:

initiation of the test: 7.9 - 8
end of the test: 8.1 - 9.4

Dissolved oxygen:

not mentioned

Nominal and measured concentrations:

Nominal: 2; 9.9; 98.6; 986 mg/L
measured: 1. meaurement: 1.2; 9.9; 70; 738 mg/L; 2. measurement: 6.3; 12.5; 88; 951 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: sterile-aerated Erlenmeyes flasks
- Initial cells density: 2x10E4 cells/mL
- Control end cells density: 127 x10E4 cells/mL
- No. of vessels per concentration (replicates): 5
- No. of vessels per control (replicates): 8
- No. of vessels per vehicle control (replicates): not applicable


GROWTH MEDIUM
- Standard medium used: yes


TEST MEDIUM / WATER PARAMETERS
no details mentioned


OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: not adjusted
- Photoperiod: not specified
- Light intensity and quality: approx. 8000 lux, white


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Cell numbers for exposure times of 24, 48, 72 h
- Determination of cell concentrations: The cell numbers were determined photometrically at a wavelenght of 685 nm
- Chlorophyll measurement: no
- Other: none


TEST CONCENTRATIONS
- Spacing factor for test concentrations: not mentioned
- Range finding study: not mentioned

Reference substance (positive control):

no

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

5.9 mg/L

Basis for effect:

biomass

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 11.7 mg/L

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

7.8 mg/L

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

6.1 mg/L

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

10 mg/L

Basis for effect:

biomass

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): no observations made
- Any stimulation of growth found in any treatment: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: yes

Effective concentrations on the basis of cell growth:
EbC50 (72 h) = 10 mg/L
EbC10 (72 h) = 6.1 mg/L
EbC90 (72 h) = not mentioned
Effective concentrations based on the specific growth rate µ:
ErC50 (0-72 h) = > 11.7 mg/L
ErC10 (0-72 h) = 7.8 mg/L
ErC90 (0-72 h) = not mentioned

Results with reference substance (positive control):

no reference substance tested

Reported statistics and error estimates:

no statistical evaluation performed

Table 1: Cell density data:

concentration [mg/mL]	cell number (x 10E4 cells/mL) after
	0 h	24 h	48 h	72 h
control	2	9	41	127
0.18	2	9	40	134
0.37	2	9	39	135
0.73	2	9	40	131
1.46	2	10	37	119
2.93	2	10	38	135
5.86	2	11	32	122
11.7	2	-5	26	50

                                                                         

Table 2: Growth curves:

concentration [mg/mL]	biomass (area under the growth curve)	inhibition of biomass [%]	growth rate µ (0 - 72 h)	inhibition of growth rate [%]
control	108.5	-	1.384	-
0.18	111	- 2.3	1.402	- 1.3
0.37	110.5	- 1.8	1.404	- 1.4
0.73	109.5	- 0.9	1.394	- 0.7
1.46	101.5	6.5	1.362	1.6
2.93	110.5	- 1.8	1.404	-1.4
5.86	99	8.8	1.37	1
11.7	41	62.2	1.073	22.5

Validity criteria fulfilled:

yes

Executive summary:

The acute toxicity of Marlowet 4753 (Coconut oil, reaction products with polyethylene glycol and trimethylolpropane) to aquatic algae Scenedesmus subspicatus was investigated in a static test according to 92/69/EEC.

On the basis of growth rate, a mean effective concentration ErC50 (72 h) was greater than the highest tested concentration of 11.7 mg/L. The NOEC based on biomass was 5.9 mg/L, the EC10 of the study based on growth rate was 7.8 mg/L. The substance was not soluble in test medium (synthetic fresh water). The concentrations were tested as emulsions, generating fine drops down to a dilution of approx. 2 mg/L.

Description of key information

The acute toxicity of Marlowet 4753 (Coconut oil, reaction products with polyethylene glycol and trimethylolpropane) to aquatic algae Scenedesmus subspicatus was investigated in a static test according to 92/69/EEC.

On the basis of growth rate, a mean effective concentration ErC50 (72 h) was greater than the highest tested concentration of 11.7 mg/L. The NOEC based on biomass was 5.9 mg/L, the EC10 of the study based on growth rate was 7.8 mg/L. The substance was not soluble in test medium (synthetic fresh water). The concentrations were tested as emulsions, generating fine drops down to a dilution of approx. 2 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

11.7 mg/L

EC10 or NOEC for freshwater algae:

5.9 mg/L