1-Propanaminium, 2-hydroxy-N-(2-hydroxyethyl)-N-methyl-N-[2-[(1-oxo-9-octadecen-1-yl)amino]ethyl]-3-sulfo-, methyl sulfate, sodium salt (1:1:1)

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:

12.11.2018 - 29.11.2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2006

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

A water accommodated fraction (WAF) equilibration trail was performed prior to exposure. The purpose of the equilibration trail is to determine the optimum mixing duration to be used for WAF preparation. One individual WAF was prepared at each of three loading levels 1.0, 50.0 and 100 mg/L. At 2, 4, 6, 24 and 72 hours after initiation of mixing, mixing was stopped and the solutions were allowed to settle for one hour. A sample of WAF was removed from each loading level and mixing was resumed. The concentration of organic carbon that had solubilized into the WAF from the test substance was measured using the TOC analyzer (TOC Analyzer/TNML; Make: Shimadzu; Model: LCPH E200 ROHS).

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Strain: ATCC 22662
- Source: American Type Culture Collection
- Method of cultivation: in OECD alga medium

ACCLIMATION
- Acclimation period:no
- Culturing media and conditions: same as test
- Any deformed or abnormal cells observed: no

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

22.1 to 22.3 °C

pH:

8.04 to 8.11

Nominal and measured concentrations:

Nominal concentration: 7.0, 12.0, 20.4, 34.6, 58.8 and 100.0 mg/L
no measured concentrations

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- Material, fill volume: glass, 250 mL
- Initial cells density: 5726 cells/mL
- Control end cells density: 961583 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes, OECD algae medium

TEST MEDIUM PARAMETERS
- Preparation of dilution water: OECD algae medium as described in OECD guideline 201

OTHER TEST CONDITIONS
- Sterile test conditions: no
- Adjustment of pH: no
- Light intensity and quality: 5232 to 5964 Lux

EFFECT PARAMETERS MEASURED
- Determination of cell concentrations: with counting chamber after 24, 48 and 72 h

TEST CONCENTRATIONS
- Range finding study: yes
- Test concentrations: 0.01, 0.1, 1.0, 10.0, 50.0 and 100.0 mg/L
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol

Key result

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

41.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EL10

Effect conc.:

17.67 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

12 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

23.35 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: yield

Details on results:

- Exponential growth in the control: yes
- Observation of abnormalities: no
- Any stimulation of growth found in any treatment: no
- Any observations that might cause a difference between measured and nominal values: no

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- ErL50 (72h): 1.11 mg/L
- EyL50 (72h): 0.29 mg/L

Table 1: Percent inhibition in cell density, growth rate and yield

Group	Nominal Loading (mg/L)	72h % Inhibition in  Cell Density	72h % Inhibition in Growth Rate	72h % Inhibition in Yield
G1	0	-	-	-
G2	7.0	6.3	1.27	6.3
G3	12.0	22.4	4.95	22.5
G4	20.4	38.0	9.37	38.3
G5	34.6	50.0	13.55	50.3
G6	58.8	89.3	44.40	89.9
G7	100.0	100	100	100

-: Not applicable 

Table 2: TOC analysis during expusure (main study)

		TOC During Exposure (mg)
Group	Nominal Loading rate (mg/L)	Day 0 (Fresh)	Day 3 (Aged)
G1	0.0	-	-
G2	7.0	2.561	1.962
G3	12.0	3.717	3.228
G4	20.4	6.617	5.542
G5	34.6	8.299	7.302
G6	58.8	19.40	17.10
G7	100.0	30.20	26.24

Validity criteria fulfilled:

yes

Conclusions:

The 72 hour EL50 and EL10 of the test item on Raphidocelis subcapitata are 41.8 mg/L and 17.67 mg/L, respectively. The 72 hours NOEC is 12 mg/L and the Lowest observed effect concentration (LOEC) is 20.4 mg/L.

Executive summary:

The test item was assessed on Raphidocelis subcapitata for Growth Inhibition Test as per the OECD Guidelines for Testing of Chemicals (Section 2), Effects on Biotic Systems, Guideline No. 201, “Freshwater Alga and Cyanobacteria, Growth Inhibition Test” adopted on 23 March 2006. A range finding study was conducted with six nominal loading rates of 0.01, 0.1, 1.0, 10.0, 50.0 and 100.0 mg/L along with control, each loading rate contains 2 replicates except control possessing 3 replicates. The algal growth (cell density) was assessed at 24, 48 and 72 hours of post-exposure during the test. During the range finding study, exponentially growing cells (5775 cells/mL) were exposed to range of selected nominal loading rates. The growth rate inhibition of 0.08, 1.20, 2.86, 4.81, 58.49 and 92.99%, was observed in the tested nominal loading rates of 0.01, 0.1, 1.0, 10.0, 50.0 and 100.0 mg/L respectively as compared with the control. Percent inhibition in yield of 0.5, 6.1, 13.7, 22.0, 54.4 and 100% was observed in the tested nominal loading rates of 0.01, 0.1, 1.0, 10.0, 50.0 and 100.0 mg/L of the test itemrespectivelyas compared with the control. Based on the results of range finding study, a main study was conducted at the nominal loading rates 7.0, 12.0, 20.4, 34.6, 58.8 and 100 mg/L along with control. The algal growth (cell density) was assessed at 24, 48 and 72 hours post-exposure. Exponentially growing alga cells (5726 cells/mL) were exposed to the selected nominal loading rates. A growth rate inhibition of 1.27, 4.97, 9.37, 13.55, 44.40 and 100 % was observed at the nominal loading rates 7.0, 12.0, 20.4, 34.6, 58.8 and 100 mg/L respectively as compared with the control. Similarly, inhibition in yield of 6.3, 22.5, 38.3, 50.0, 89.3 and 100% was observed at the nominal loading rates 7.0, 12.0, 20.4, 34.6, 58.8 and 100 mg/L respectively as compared with the control. The present alga growth inhibition study fulfills the validity criteria of the test. The following results were calculated:The 72 hours EL10 value for growth rate (ErL10) is 17.67 mg/L (Effective Loading). The 72 hours EL10 value for yield (EyL10) is 9.30 mg/L (Effective Loading). The 72 hours EL50 value for growth rate (ErL50) is 41.80 mg/L (Effective Loading). The 72 hours EL50 value for yield (EyL50) is 23.35 mg/L (Effective Loading). The 72 hours No Observed Effect Loading Rate (NOEL) is 12.0 mg/L and Lowest Observed Effect Loading Rate (LOEL) is 20.4 mg/L, respectively. All results are based on the nominal loading rate concentrations.

Description of key information

The 72 hour EL50 and EL10 of the test item on Raphidocelis subcapitata are 41.8 mg/L and 17.67 mg/L, respectively. The 72 hours NOEC is 12 mg/L and the Lowest observed effect concentration (LOEC) is 20.4 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

41.8 mg/L

EC10 or NOEC for freshwater algae:

17.67 mg/L

Additional information

The test item was assessed on Raphidocelis subcapitata for Growth Inhibition Test as per the OECD Guidelines for Testing of Chemicals (Section 2), Effects on Biotic Systems, Guideline No. 201, “Freshwater Alga and Cyanobacteria, Growth Inhibition Test” adopted on 23 March 2006. A range finding study was conducted with six nominal loading rates of 0.01, 0.1, 1.0, 10.0, 50.0 and 100.0 mg/L along with control, each loading rate contains 2 replicates except control possessing 3 replicates. The algal growth (cell density) was assessed at 24, 48 and 72 hours of post-exposure during the test. During the range finding study, exponentially growing cells (5775 cells/mL) were exposed to range of selected nominal loading rates. The growth rate inhibition of 0.08, 1.20, 2.86, 4.81, 58.49 and 92.99%, was observed in the tested nominal loading rates of 0.01, 0.1, 1.0, 10.0, 50.0 and 100.0 mg/L respectively as compared with the control. Percent inhibition in yield of 0.5, 6.1, 13.7, 22.0, 54.4 and 100% was observed in the tested nominal loading rates of 0.01, 0.1, 1.0, 10.0, 50.0 and 100.0 mg/L of the test itemrespectivelyas compared with the control. Based on the results of range finding study, a main study was conducted at the nominal loading rates 7.0, 12.0, 20.4, 34.6, 58.8 and 100 mg/L along with control. The algal growth (cell density) was assessed at 24, 48 and 72 hours post-exposure. Exponentially growing alga cells (5726 cells/mL) were exposed to the selected nominal loading rates. A growth rate inhibition of 1.27, 4.97, 9.37, 13.55, 44.40 and 100 % was observed at the nominal loading rates 7.0, 12.0, 20.4, 34.6, 58.8 and 100 mg/L respectively as compared with the control. Similarly, inhibition in yield of 6.3, 22.5, 38.3, 50.0, 89.3 and 100% was observed at the nominal loading rates 7.0, 12.0, 20.4, 34.6, 58.8 and 100 mg/L respectively as compared with the control. The present alga growth inhibition study fulfills the validity criteria of the test. The following results were calculated: The 72 hours EL10 value for growth rate (ErL10) is 17.67 mg/L (Effective Loading). The 72 hours EL10 value for yield (EyL10) is 9.30 mg/L (Effective Loading). The 72 hours EL50 value for growth rate (ErL50) is 41.80 mg/L (Effective Loading). The 72 hours EL50 value for yield (EyL50) is 23.35 mg/L (Effective Loading). The 72 hours No Observed Effect Loading Rate (NOEL) is 12.0 mg/L and Lowest Observed Effect Loading Rate (LOEL) is 20.4 mg/L, respectively. All results are based on the nominal loading rate concentrations.