Oligomerisation products of ethylene oxide with reaction products of rape oil and ethanolamine

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:

From 31 January 2000 to 18 April 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Stock solution of the test substance
(1) 1.25 g/L ultrapure water (Seral, purelab plus)
(2) 0.0125 g/L ultrapure water (Seral, purelab plus); this solution was prepared by diluting solution (1) 1:100

Vehicle:

no

Details on test solutions:

Mineral Nutrient Salts:
NH4Cl: 1.5g
MgCl2·6H2O: 1.2g
CaCl2·2H2O: 1.8g
MgSO4·7H2O: 1.5g
KH2PO4: 0.16g
dissolved in 1L ultrapure water

Fe-Complex:
FeCl3·6H2O:0.08g
Na2EDTAx2H2O: 0.10g
dissolved in 1L ultrapure water

Trace-Elements:
H3BO3 :185 mg
MnCl2·4H2O: 415 mg
ZnCl2: 3mg
CoCl2·6H2O: 1.5mg
CuCl2·2H2O: 0.01mg
Na2MoO4·2H2O: 7mg
dissolved in 1L ultrapure water

Sodium Hidrogen carbonate:
NaHCO3: 1.0g

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: Scenedesmus subspicatus CHODAT
- Source (laboratory, culture collection): Sammlung von Algenkulturen, Pflanzenphysiologisches Institut der Universität Göttingen

Test type:

not specified

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

24 to 25.5 ºC

pH:

10.55

Nominal and measured concentrations:

Screening-Test: 0.1, 1, 10, 100 mg/L and control
Main Test: 2.5, 5, 10, 20, 40, 80 mg/L and control

Details on test conditions:

TEST SYSTEM
Stock solutions were made in ultrapure water.
One part of the stock solutions was diluted according to the table below and inoculated with the algal suspension.
The second part was diluted equivalent to the test solution the algal suspension being replaced by a 1:10 diluted intermediate dilution blank.
These blanks were incubated under the same conditions under constant light as the test solution to be tested.
The measured turbidityin those test solution was subtracted from those with the algal inoculation. In the same way, seven control solutions without any test substance but with algal inoculation were prepared as well as one test solution without any test substance and without algal inoculation.

Reference substance (positive control):

no

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

3.2 mg/L

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

4.9 mg/L

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

4.7 mg/L

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

22 mg/L

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

11.9 mg/L

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

410 mg/L

Basis for effect:

growth rate

*

	Number	of	cells [1/mL]		Inhibition of Biomass	Inhibition of the
Concnetration of the test substance [mg/L]	t0	t25h	t49h	t72h	Production [%] EbC	Growth Rate [%] ErC	t0	t72h
Control	7.43*10^4	4.01*10^5	1.17*10^6	3.69*10^5	0.0	0.0	8.23	10.55
80	7.28*10^4	-*)	1.36*10^5	8.10*10^6	89.3	38.3	8.24	8.86
40	8.03*10^4	5.03*10^4	3.52*10^5	1.89*10^6	64.4	19.0	8.26	9.79
20	8.18*10^4	1.94*10^5	6.27*10^5	2.76*10^6	37.9	9.9	8.32	10.08
10	8.33*10^4	8.43*10^5	8.43*10^5	3.13*10^6	23.7	7.2	8.32	10.33
5	7.80*10^4	9.13*10^5	9.13*10^5	3.17*10^6	20.2	5.1	8.31	10.42
2.5	7.60*10^4	2.96*10^5	9.23*10^5	3.10*10^6	20.2	5.0	8.27	10.39

Validity criteria fulfilled:

yes

Conclusions:

NOEC(72h)=3.2 mg/L (biomass)
NOEC(72h)=4.9 mg/L (growth rate)
ErC50=410 mg/L
EbC50= 22 mg/L

Executive summary:

The chronic toxicity of the subtance towads algae was tested according to OECD Guideline 201. The toxic effect was investigated by determination of the inhibition of the biomass production and the growth rate of the algae after an exposure period of 72 h. Under the conditions being tested the NOEC (no observed effect concentration) was determined as being 3.2 mg/L for biomass production and 4.9 mg/L for the growth rate. The inhibition of the growth rate to 50% (ErC50) was calculated as being 410mg/L and EbC50 as being 22 mg/L.

Description of key information

The chronic toxicity of the subtance towads algae was tested according to OECD Guideline 201. The toxic effect was investigated by determination of the inhibition of the biomass production and the growth rate of the algae after an exposure period of 72 h.

Key value for chemical safety assessment

EC50 for freshwater algae:

410 mg/L

EC10 or NOEC for freshwater algae:

4.9 mg/L

Additional information

Under the conditions of the test the following results were determined:

NOEC (biomass): 3.2 mg/l

NOEC (growth rate): 4.9 mg/l

EbC50 (biomass): 22 mg/l

ErC50 (growth rate): 410 mg/l.

For the purposes of chemical safety assessment and classification the results based on growth rate are the key values.