Dimethyl[2-[(2-methyl-1-oxoallyl)oxy]ethyl](3-sulphopropyl)ammonium hydroxide

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:

2017-03-20 - 2017-04-27

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-04-25 - 2017-04-27 (experimental phase)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

OECD Guideline for Testing of Chemicals No. 202, adopted 13. Apr. 2004: ”Daphnia sp., Acute Immobilisation Test“

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

Council Regulation (EC) No. 440/2008, Method C.2. “Daphnia sp. Acute Immobilisation Test”, adopted 30. May 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: The test item was stored in a closed vessel at room temperature (20 ± 5°C), away from humidity

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0, 100 mg/L

Vehicle:

no

Details on test solutions:

- Method: A test solution containing 101.4 mg/L test item in dilution water was prepared by direct addition, to prepare the limit test concentration of nominal 100 mg/L.
- Controls: Blank control were 4 vessels, each containing 20 ± 5 mL dilution water and 5 Daphnia
- Evidence of undissolved material (e.g. precipitate, surface film, etc): none stated

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: Berlin (Origin: Umweltbundesamt Berlin)
- Source: Daphnia magna is bred in the LAUS GmbH throughout the year. The animals are kept for the use in toxicity tests. They multiply by parthenogenesis, thus being genetically identical.
- Age of parental stock (mean and range, SD): In-house breeding since 2007-09-27
- Husbandry: The husbandry is performed similar to the method described in EN ISO 6341
Vessels: preserving glasses, nominal volume 2 L
Medium: M4-Medium (recipe of ELENDT)
Food: unicellular green algae (Desmodesmus subspicatus)
Medium renewal: twice a week
Photo period: 16/8 hours, using neon tubes
Temperature: 20 ± 2 °C
- Feeding during test: no

ACCLIMATION
- Acclimation period: none
- Acclimation conditions (same as test or not): Not the same, but switching from M4-medium (husbandry) to Dilution water (test) has been shown not to cause any detrimental effects for test Daphnia.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

no

Hardness:

2.502 mmol/L; 250 mg CaCO3/L

Test temperature:

19.8 – 21.1 °C

pH:

7.6 - 7.7 at test start
7.8 - 7.9 at test end

Dissolved oxygen:

8.5 - 8.9 at test start
8.4 - 8.5 at test end

Nominal and measured concentrations:

Nominal: 100 mg/L (The study was performed as a limit test because in a non-GLP pre-test at the concentrations 1 / 10 / 100 mg/L no toxicity was observed)
Measured: t0h = 98 mg/L, t48h = 107 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers, nominal volume 50 mL, tall shape
- Type (delete if not applicable): open
- Aeration: no
- Medium renewal: none
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:
Dilution water specification:
Parameter Concentration in mg/L
CaCl2*2H2O 293.80
MgSO4*7H2O 123.30
NaHCO3 64.80
KCl 5.80
Deviations from the nominal weighted loads were less than 5%. Exact values ae recorded in the raw data. After preparation, the dilution water was aerated and the pH was meas-ured. The pH was 7.7.
- Culture medium different from test medium: yes

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16/8 hours, using neon tubes

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : After 24 and 48 hours, the immobilised Daphnia were counted. The pH and the concentration of dissolved oxygen were measured at the beginning and at the end of the test.

VEHICLE CONTROL PERFORMED: no

RANGE-FINDING STUDY
- Test concentrations: 0 / 1 / 10 / 100 mg/L
- Results used to determine the conditions for the definitive study: since no immobilisation was observed in the non-GLP range-finder the definitive study was performed as a limit test at 100 mg/L nominal.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9) was used as positive control in a current reference study to assure that the test conditions are reliable.

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: none stated
- Mortality of control: 0%
- Other adverse effects control: none stated
- Abnormal responses: none stated
- 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: no

Results with reference substance (positive control):

Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9) was used as positive control in a current reference study (16102801R201). The 24h-EC50 value was determined to be 1.8 mg/L. The 24h-EC50 of K2Cr2O7 should lie between 0.6 and 2.1 mg/L.

Reported statistics and error estimates:

95% confidence interval could not be determined as no immobilisation occurred.

Validity criteria fulfilled:

yes

Conclusions:

The study was conducted under GLP according to OECD guideline 202 and EU method C.2 on the registered substance itself. The method is to be considered scientifically reasonable with no deficiencies in documentation or deviations from the guidelines, the validity criteria were met. Hence, the results can be considered as reliable to assess the toxicity of SPE towards daphnids.
The toxicity against Daphnia magna was tested in a static limit test at a nominal test concentration of 100 mg/L. The concentrations showed no toxicity. None of the animals were immobilised neither in the treatment nor in the control.
Based on the obtained results, sodium N,N-Dimethyl-N-(2-methacryloyloxyethyl)-N-(3-sulfopropyl)-ammonium betaine; (SPE) does not need to be classified as hazardous to the aquatic environment according to the Regulation (EC) No. 1272/2008.

Executive summary:

The acute toxicity of N-[2-(methacryloyloxy)ethyl]-N,N-dimethyl-3-sulfopropan-1-aminium hydroxide was determined in a study according to OECD TG 202 under GLP.

Findings and Results:

One valid experiment was performed.

The study was performed as a limit test at the concentration 100 mg/L. 20 Daphnia were exposed to the test item for 48 hours in a static test system. After 24 and 48 hours, the immobilised Daphnia were counted.

The treatment showed no significant toxicity. None of the animals were immobilised in the blank control, only 1 animal (5 % total) was immobilised in the treatment.

Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9) was used as positive control in a current reference study to assure that the test conditions are reliable.

At the beginning and at the end of the test, the content of the test item in the test solutions was determined using HPLC - determination. The measured concentration was 98 % and 107 % of the nominal concentration. Therefore, the determination of the biological results was based on the nominal concentration.

The following results were determined for the test item N,N-Dimethyl-N-(2 -methacryloyloxyethyl)-N-(3-sulfopropyl)-ammonium betaine; (SPE) (species: Daphnia magna).

48h-NOEC ≥ 100 mg/L

48h-LOEC > 100 mg/L

24h-EC50 > 100 mg/L

48h-EC50 > 100 mg/L

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

Version adopted 23. Mar. 2006, Annex 5 corrected: 28 July 2011

Deviations:

yes

Remarks:

Deviations from the Study Plan: The concentration of the stock solution was slightly higher than stated in the study plan. As the biological results were based on the measured concentrations, this can be stated as uncritical.

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

Version adopted 07. December 2015

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Dimethyl[2-[(2-methyl-1-oxoallyl)oxy]ethyl](3-sulphopropyl)ammonium hydroxide

EC Number:

222-860-8

EC Name:

Dimethyl[2-[(2-methyl-1-oxoallyl)oxy]ethyl](3-sulphopropyl)ammonium hydroxide

Cas Number:

3637-26-1

Molecular formula:

C11H21NO5S

IUPAC Name:

dimethyl[2-[(2-methyl-1-oxoallyl)oxy]ethyl](3-sulphopropyl)ammonium hydroxide

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room Temperature (20 ± 5°C), keep away from humidity

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0, 10, 18, 32, 56, 100 mg/L
- Sampling method: not specified. Samples for the analytical determination were taken at test start and test end.
- Sample storage conditions before analysis: not specified

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution containing 102.0 mg/L test item in algal medium (demineralised water enriched with minerals but without algae) was prepared. Lower test concentrations were prepared by serial dilution of the stock solution in algal medium.
- Controls: medium without any test item
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): none stated

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: Desmodesmus subspicatus (unicellular freshwater green alga)
- Strain: Sammlung von Algenkulturen, Pflanzenphysiologisches Institut der Universität Göttingen [SAG], Strain-No. 86.81
- Source (laboratory, culture collection): The culture of Desmodesmus subspicatus was obtained in January 2016 by MBM Sciencebridge GmbH (Institut für Pflanzenphysiologie of Universität Göttingen)
- Age of inoculum (at test initiation): 4 days
- Method of cultivation: The algae are kept as stock culture on solid agar at 2 - 8 °C. From the stock culture, a permanent culture was prepared. From an aliquot of the permanent culture, the pre-culture was prepared.

ACCLIMATION
- Acclimation period: 4 days
- Culturing media and conditions (same as test or not): An aliquot of the permanent culture was brought into nutrient medium and incubated under continuous lighting for 96 hours. The resulting culture grew exponentially.
Before usage, the pre-culture was checked for the absence of cell aggregates and the cell number of culture was determined.
- Any deformed or abnormal cells observed: no

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

23.1 - 24.0 °C

pH:

8.1 - 8.2 at test start
8.7 - 9.1 at test end

Nominal and measured concentrations:

Nominal: 0, 10, 18, 32, 56, 100 mg/L
Found (t0): Found (t72h): Geometric mean measured concentration (0-72h): 0, 6.93, 13.86, 26.09, 49.97, 85.23 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: flasks
- Type (delete if not applicable): open (covered with perforated plastic foil)
- Material, size, headspace, fill volume: glass flasks with a total volume of 65 mL, filled with 45 ± 1 mL of the respective test solution
- Initial cells density: 2*10E3 cells/mL
- Control end cells density: 686510 cells/mL (mean)
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:

Stock Solution I:
NH4Cl 1500 mg
MgCl2*6H2O 1200 mg
CaCl2*2H2O 1800 mg
MgSO4*7H2O 1500 mg
KH2PO4 160 mg
H2O deionised ad 1000 mL

Stock Solution II:
FeCl3*6H2O 64 mg
Na2EDTA*2H2O 100 mg
H2O deionised ad 1000 mL

Stock Solution III:
H3BO3 185 mg
MnCl2*4H2O 415 mg
ZnCl2 3 mg
CoCl2*6H2O 1.5 mg
CuCl2*2H2O 0.01 mg
Na2MoO4*2H2O 7 mg
H2O deionised ad 1000 mL

Stock Solution IV:
NaHCO3 50 g
H2O deionised ad 1000 mL

Algal Medium:
Stock Solution I 10.0 mL
Stock Solution II 1.0 mL
Stock Solution III: 1.0 mL
Stock Solution IV 1.0 mL
H2O deionised ad 1000 mL

Deviations from the nominal weighted loads were less than 5%.

- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Photoperiod: continous
- Light intensity and quality: illumination rate of 7200 Lux]

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: before the start of incubation and every 24 hours, the cell number was determined with an electronic particle counter

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.7 - 1.8
- Test concentrations: 0, 10, 18, 32, 56, 100 mg/L

Reference substance (positive control):

yes

Remarks:

Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9) was used as positive control in a separate reference test.

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 85.23 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

other: growth rate and yield

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 85.23 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 6.93 - < 13.86 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

other: yield

Effect concentrations 4

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

13.86 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

other: growth rate and yield

Effect concentrations 5

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

6.93 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

other: growth rate and yield

Effect concentrations 6

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: growth rate and yield

Effect concentrations 7

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 8

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 10 - < 18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: yield

Effect concentrations 9

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: growth rate and yield

Effect concentrations 10

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: growth rate and yield

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): normal and healthy appearance of the algae at the end of the test
- Unusual cell shape: no
- Colour differences: no
- Flocculation: not stated
- Adherence to test vessels: not stated
- Aggregation of algal cells: not stated
- Any stimulation of growth found in any treatment: A very slight stimulation of algal growth compared to the control was observed at the lowest test concentration of nominal 10 mg/L for the parameter yield (0.11%) and the parameter growth rate (0.05%).
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: During the validation of the analytical method the test item showed a mean stability of 96.8 % of a 10 mg/L and 100 mg/L solution in algal medium under test conditions without algal cells over 3 days. With the presence of algal cells stability was lower. The measured concentrations lay between 97 % and 103 % of the nominal concentrations at the beginning of the test and between 50 % and 77 % of the nominal concentrations at the end of the test.
- Effect concentrations exceeding solubility of substance in test medium: no

Results with reference substance (positive control):

The 72h-EC50s of potassium dichromate were determined in a separate reference test. For the estimation of the 72h-EC50s of the positive control, the fits showed sufficient statistical correspondence of the data with the dose-response-equation. The values were within the range of the laboratory. The results of the last study with the positive control K2Cr2O7 were:
72h ErC50 = 0.80 mg/L (0.78 - 0.83 mg/L)
72h EyC50 = 0.54 mg/L (0.52 - 0.56 mg/L)
The study was performed under GLP conditions in October 2016.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The study was performed according to OECD TG 201 with no relevant deviations (only one minor deviation from the study plan with no influence on the integrity of the study, see "Material and Methods", "Test guideline"), the results were so obtained via a scientifically reasonable method. The validity criteria for the study as given by the OECD Guideline 201 were met and the study is therefore considered to be valid. Hence, there is no doubt that the obtained results are not reliable: The toxic effect was investigated by determination of the inhibition of the growth rate of the algae and the yield during the exposure period of 72 hours. The maximum concentration investigated was 100 mg/L (nominal), corresponding to 85.23 mg/L (geometric mean measured).
At the start and at the end of the test, the content of the test item in the test solutions was determined using HPLC. The measured concentrations lay between 97 % and 103 % of the nominal concentrations at the beginning of the test and between 50 % and 77 % of the nominal concentrations at the end of the test. During the validation of the analytical method the test item showed a mean stability of 96.8 % of a 10 mg/L and 100 mg/L solution in algal medium under test conditions without algal cells over 3 days. With the presence of algal cells stability was lower. Therefore, the geometric mean of the measured concentration was used for the determination of the results. Geometric mean is calculated by multiplication of the n participating concentrations and taking the nth root.
The following EC-values (72h; growth rate; geometric mean measured concentrations) were determined accordingly:
LOEC (growth rate and yield) = 13.86 mg/L
NOEC (growth rate and yield) = 6.93 mg/L
EC50 (growth rate and yield) > 85.23 mg/L
Based on these results, the test item does not need to be classified as acute toxic to the aquatic environment. With regard to chronic toxicity, taking into account the facts that the test item is soluble in water, i.e. above the determined EC50 value, and not readily biodegradable, the test item should be in theory, taking into account a EC50 which was not proven to be >100 mg/L, classified as aquatic chronic Cat. 3 according to the Regulation (EC) No. 1272/2008.
However, at the start of the test the measured concentrations of N,N-Dimethyl-N-(2-methacryloyloxyethyl)-N-(3 -sulfopropyl)-ammonium betaine; (SPE) were within ± 20 % of the nominal concentration, wherefore the biological results were based on the nominal concentrations in addition. Based on nominal concentrations the EC10 and the EC50 (72h) for the relevant parameter growth rate were determined to be > 100 mg/L. The actual ErC10 and ErC50 could not be calculated statistically due to the low effects, but assuming a realistic dose-response-curve it is expected to be significant higher than nominal 100 mg/L, corresponding to 85.23 mg/L based on geometric mean measured concentrations.
As stated for the validation of the analytical method the test item was stable under test conditions without algal cells over 3 days, with a mean stability of 96.8 % for a 10 mg/L and 100 mg/L solution in algal medium. With the presence of algal cells stability was lower, which will be the case in the aquatic environment as well.
Within the acute study on Daphnia performed under GLP according OECD TG 202 in the same lab than the study on algae (see “Cross-reference” section Administrative data) the test item N,N-Dimethyl-N-(2-methacryloyloxyethyl)-N-(3 -sulfopropyl)-ammonium betaine; (SPE) was stable for the test duration of 48 hours and no immobilization or other signs of intoxication were determined at all. Accordingly the test item did not have to be classified as acute or chronic toxic to the aquatic environment.
Taking into account these additional explanations N,N-Dimethyl-N-(2-methacryloyloxyethyl)-N-(3 -sulfopropyl)-ammonium betaine; (SPE) is not considered to be harmful to the environment and is not classified as acute or chronic toxic to the aquatic environment based on the results of the algae study as well.

Executive summary:

The study was performed according to OECD TG 201 under GLP using 5 concentrations ranging from 10 to 100 mg/L. Incubation time (test system Desmodesmus subspicatus) was 72 hours. The cell concentration of each replicate was determined by measuring the cell numbers every 24 hours with an electronic particle counter. Growth rate µ and the yield were determined from the cell number at the respective observation times.

Significant inhibition of algal growth was observed at the following concentrations: 18 / 32 / 56 / 100 mg/L nominal concentration

At the start and at the end of the test, the content of the test item in the test solutions was determined using HPLC. The measured concentrations lay between 97 % and 103 % of the nominal concentrations at the beginning of the test and between 50 % and 77 % of the nominal concentrations at the end of the test. During the validation of the analytical method the test item showed a mean stability of 96.8 % of a 10 mg/L and 100 mg/L solution in algal medium under test conditions without algal cells over 3 days. With the presence of algal cells stability was lower. Therefore, the determination of the results was based on the geometric mean of the measured concentrations. As the measured concentrations at the start of the test were within ± 20 % of the nominal concentration the biological results were additionally based on the nominal concentrations.

As in the 4 highest treatments inhibition of algal growth was in the same range and below 10 % regarding the endpoint growth rate and below 50 % regarding the endpoint yield, only the NOEC and LOEC was determined via ToxRat® Professional.

The 72h-EC50s of potassium dichromate (K2Cr2O7, CAS No. 7778-50-9) were determined in a separate reference test. The values lay within the range of the laboratory (growth rate 0.73 - 1.10 mg/L, yield 0.21 - 0.66 mg/L).

The following results for the test item N,N-Dimethyl-N-(2-methacryloyloxyethyl)-N-(3 -sulfopropyl)-ammonium betaine; (SPE) were determined:

Results of the test item based on measured concentrations

Endpoint	NOEC	LOEC	EC10	EC50
Growth Rate	6.93 mg/L	13.86 mg/L	> 85 mg/L	> 85 mg/L
Yield	6.93 mg/L	13.86 mg/L	between 6.93 - 13.86 mg/L	> 85 mg/L

Results of the test item based on nominal concentrations

Endpoint	NOEC	LOEC	EC10	EC50
Growth Rate	10 mg/L	18 mg/L	> 100 mg/L	> 100 mg/L
Yield	10 mg/L	18 mg/L	between 10 - 18 mg/L	> 100 mg/L