Amines, C20-22-alkyldimethyl

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 23 March 2010 to 15 April 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: According to the OECD 201 and it is GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

ISO 8692 (Water Quality - Fresh Water Algal Growth Inhibition Test with Scenedesmus subspicatus and Selenastrum capricornutum)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Amines, C20-22-alkyldimethyl

EC Number:

296-866-4

EC Name:

Amines, C20-22-alkyldimethyl

Cas Number:

93164-85-3

Molecular formula:

CnH2nN(CH3)2 n: from 18 to 22

IUPAC Name:

Amines, C20-22-alkyldimethyl

Details on test material:

- Physical state: white solid
- Storage: at room temperature in the dark under nitrogen
- Stability under storage conditions: stable

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Preparation of test solution started with an aqueous mixture at a loading rate of 100 mg/L. This mixture was magnetically stirred for 21 hours (final test) or 22 hours (combined limit/range-finding) after which the resulting dispersion was left to settle for 4 hours. After settlement a clear solution with a floating layer was obtained. The Water Soluble Fraction (WSF) was collected by siphoning the middle fration through glass wool after it was used for testing. The control received similar treatment related effects. The lower test concnetration were prepared by subsequent dilution of the WSF in test medium. All final test solution were clear and colourless.

Test solutions

Vehicle:

no

Details on test solutions:

Volumes of 50mL were added to each replicates of the respective test concentration. Subsequently, 1 mL of an algal suspension was added to each replicate providing a cell density of 10^4 cells/mL.

Test organisms

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchneriella subcapitata, strain NIVA CHL 1
- Source (laboratory, culture collection): in-house laboratory culture

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

pH:

8.1

Nominal and measured concentrations:

0.10, 0.32, 1.0, 3.2, 10 and 32% of a WSF prepared at a loading rate of 100 mg/L

Details on test conditions:

-Test vessels: 100mL, all-glass, containing 50 mL of the test solution
Replicates
3 replicates of each test concnetration
6 repliactes of the control
2 replicates of the highest concentration without algae
1 replicate of each test concentration for sampling purposes.
Controls: test medium without test substance or other additives

Reference substance (positive control):

yes

Results and discussion

Effect concentrations

Effect concentrations 1

Dose descriptor:

NOEC

Effect conc.:

0.16 µg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.26 µg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 0.02-3.2

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

1.7 µg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 0.15-20

Effect concentrations 4

Dose descriptor:

NOEC

Effect conc.:

0.16 µg/L

Conc. based on:

test mat.

Basis for effect:

other: yield

Effect concentrations 5

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.26 µg/L

Conc. based on:

test mat.

Basis for effect:

other: yield

Remarks on result:

other: 0.04-0.76

Effect concentrations 6

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.62 µg/L

Conc. based on:

test mat.

Basis for effect:

other: yield

Remarks on result:

other: 0.16-2.4

Any other information on results incl. tables

Mean cell densities (x10^4 cellss/mL) during the combined limit/range-finding test

Test substance	Exposure	time	(hours)
%WSF / initial µg/L	0	24*	48*	72*
control	1.0	4.1	24.2	115.2
0.10 / 0.6	1.0	4.5	24.0	114.4
1.0 / 6.0	1.0	4.1	20.0	92.5
10 / 60	1.0	1.0	1.0	1.0
100 / 600	1.0	1.0	1.0	1.0

* Droplets were observed against wall of test vessels. These disappeared when shaking the vessels

Percentage reduction of growth rate and inhibition of yield during the combined limit/range-finding test

Test substance	Mean growth rate	Mean growth rate	Yield (0 -72h)	Yield (0 -72h)
%WSF / initial µg/L	µ (0 -72h)	Reduction (%)	x10^4 cells/mL	inhibition (%)
control	0.06589		114.18
0.10 / 0.6	0.06583	0.1	113.43	0.7
1.0 / 6.0	0.06272	4.8	91.46	19.9
10 / 60	0.00000	100.0	0.00	100.0
100 / 600	0.00000	100.0	0.00	100.0

Measured concentrations versus nominal concentrations

% WSF	Measured conc. t= 0 h (µg/L)	Measured conc. t= 24 h (µg/L)	Mesured conc. t=72 h (µg/L)	TWA conc. (µg/L)
0.10	0.139	0.045*	0.045*	0.06
0.32	0.443	0.045*	0.045*	0.08
1.0	3.23	0.045*	0.045*	0.16
3.2	8.53	0.174	0.161	0.52
10	30.9	1.10	0.587	2.48
32	101	0.412	0.316	2.39

*Concentration used is half the LOD (LOD=0.090µg/L)

Mean cell density (x10^4 cells/mL) during the final test

%WSF / TWA µg/L	Exposure	time	(hours)
	0	24	48	72
control	1.0	9.4	31.6	160.4
0.10 / 0.06	1.0	9.7	33.6	161.2
0.32 / 0.08	1.0	9.4	30.5	161.1
1.0 / 0.16	1.0	10.2	33.4	163.7
3.2 / 0.52	1.0	6.5	14.1	65.1
10 / 2.48	1.0	3.7	7.3	30.1
32 / 2.39	1.0	1.4	1.0	2.6

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the present study Pseudokirchneriella subcapitata, reduce growth rate and inhibited the yield of this fresh water algae species significantly at TWA concentrations of 0.52µg/L and higher.
the EC50 for growth rate reduction (ErC50:0-72h) was estimated to be 1.7 µg/L with a 95% confidence interval ranging from 0.15 to 20µg/L.
The EC50 for yield inhibition (E γC50:0 -72h) was 0.62µg/L with a 95% confidence interval ranging from 0.16 to 2.4µg/L. The NOEC for both growth rate reduction and yield inhibition was 0.16µg/L.

Executive summary:

The study procedures described in this report were based on the OECD Guideline No.201.

Analyses of samples taken at the start of the test showed measured concentrations of 0.139, 0.443, 3.23, 8.53, 30.9 and 101µg/L in The test solution containing 0.10, 0.32, 1.0, 3.2, 10 and 32% of the WSF, respectively. The study met the acceptability criteria prescribed by the protocol and was considered valid. the substance reduced growth rate and inhibited the yield of this fresh water algae especies significantly at TWA concentrations of 0.52µg/L and higher. The EC50 for growth rate reduction (ERC50:0 -72h) was estimated to be 1.7µg/L with a 95% confidence interval ranging from 0.15 to 20µg/L. The EC50 for yield inhibition (E γC50:0 -72h) was 0.62µg/L with a 95% confidence interval ranging from 0.16 to 2.4µg/L. The NOEC for both growth rate reduction and yield inhibition was 0.16µg/L.