Reaction mass of 2-amino-2-methyl-1-propanol hydrochlorid (3207-12-3) and 2-amino-2-methyl-1-propanol (124-68-5)

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 2018-05-07 to 2018-06-30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

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)

Test material

Test material information

1

Reference substance name:

(2-hydroxy-1,1-dimethylethyl)ammonium chloride

EC Number:

221-713-5

EC Name:

(2-hydroxy-1,1-dimethylethyl)ammonium chloride

Cas Number:

3207-12-3

Molecular formula:

C4H11NO.ClH

IUPAC Name:

1-hydroxy-2-methylpropan-2-aminium chloride

Test material form:

liquid

Sampling and analysis

Analytical monitoring:

no

Details on sampling:

Due to complexity of test item, test concentration analysis was not possible.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Stock solution was freshly prepared prior to exposure by weighing required quantity of test item in a beaker and the subsequent addition of OECD alga media. The stock solution was mixed well using a glass rod. After the complete solubility of the test item, the stock solution was transferred into a measuring cylinder. A magnetic stirrer was used to maintain the homogeneity of the stock solution. The required test concentratons were prepared by adding appropiate amount of stock solutions and make up to the required volume using OECD alga medium.
- Controls: Positive control performed with 3,5 - dichlorophenol and blank control performed with the test solution without the test substance.

Test organisms

Test organisms (species):

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

Details on test organisms:

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

ACCLIMATION
- Culturing media and conditions were the same as the test.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Remarks on exposure duration:

None

Post exposure observation period:

Not performed

Test conditions

Hardness:

No data

Test temperature:

21 to 24 °C

pH:

No data

Dissolved oxygen:

No data

Salinity:

Not appliceble

Conductivity:

No data

Nominal and measured concentrations:

- Nominal concentrations: 0 (control), of 0.0131, 0.131, 1.31, 13.10, 65.5 and 131 mg/L
- Measured concentrations: No concentrations were measured

Details on test conditions:

TEST SYSTEM
- Test vessel: Sterilized, glass conical flasks (Erlenmeyer flasks) of 250 mL
- Fill volume: 100 mL
- Initial cells density: 5561 cells/mL
- Control end cells density: 5000 - 10000 cells/mL
- 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: The dilution water was prepared according to guideline
- Culture medium different from test medium: No
- Intervals of water quality measurement: The temperature (culture medium) and light intensity were monitored at least once in a day during pre-culture and exposure. The pH of the test concentrations was measured at the beginning (0 hours) and at the end (72 hours) of the exposure.

OTHER TEST CONDITIONS
- Sterile conditions: Yes
- Adjustment of pH: No
- Light intensity and quality: 4440 to 8880 lux


EFFECT PARAMETERS MEASURED: Growth and yield inhibition rate after 72 hours

TEST CONCENTRATIONS
- Test concentrations of the range finding study: 0 (control), of 0.0131, 0.131, 1.31, 13.10, 65.5 and 131 mg/L
- Results used to determine the conditions for the definitive study: During the range finding study, exponentially growing cells (5462 cells/mL) were exposed to range of selected concentrations. The growth rate inhibition of 0.11, 0.59, 0.98, 1.20, 1.58 and 1.78 % were observed in the tested concentrations of 0.0131, 0.131, 131, 13.10, 65.5 and 131 mg/L of the test item respectively as compared with the control.
Percent inhibition in yield of 0.6, 3.0, 4.9, 6.0, 7,8 and 8.7 % was observed in the tested concentrations of 0.0131, 0.131, 1.31, 13.10, 65.5 and 131 mg/L of the test substance respectively as compared with the control. Based on the results of range finding study, a limit test was conducted at the concentration of 131 mg/L.

Reference substance (positive control):

yes

Remarks:

3, 5 - dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 131 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 131 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

131 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 131 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 5

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 131 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 6

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

131 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

- Exponential growth in the control (for algal test): Yes
- Observation of abnormalities (for algal test): Not observed
- Unusual cell shape: Not observed
- Colour differences: Not observed
- Flocculation: Not observed
- Adherence to test vessels: Not observed
- Aggregation of algal cells: Not observed
- Any stimulation of growth found in any treatment: No
- Any observations that might cause a difference between measured and nominal values: No
- Effect concentrations exceeding solubility of substance in test medium: No
The algae cells were found healthy and normal in blank control and treatment groups. No treatment related changes were observed in the algal cell counts at 24, 48 and 72 hours exposure period during range finding and limit test (131 mg/L).
During limit test, percent inhibition in yield of 2.8 % was observed in the tested concentration of 131 mg/L.
The 72 hours ErC10 and ErC50 (growth rate), EyC10 and EyC50 (yield) of the test substance on Raphidocelis subcapitata was determined to be greater than 131 mg/L. The 72 hours No Observed Effect Concentration (NOEC) and the Lowest observed effect concentration (LOEC) were determined to be greater than 131 mg/L. The results are based on the nominal concentrations.

Results with reference substance (positive control):

- EC50: 1.28 mg/L
- Results with reference substance valid?: Yes. The 72 hours growth rate inhibition and percent inhibition in yield lies within the validity criteria acceptance range and establishes the acceptability of test system response and test procedures followed.

Reported statistics and error estimates:

The response variable in the control and treatment group was analyzed using a statistical Student’s t-test to compare means.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 72 hours ErC10 and ErC50 (growth rate), EyC10 and EyC50 (yield) of the test substance on Raphidocelis subcapitata was determined according to the principles of OECD 201 (2011) in a static growth inhibition test under GLP conditions. After 72 hours the NOEC was determined to be 131 mg/L. The ErC10 and the ErC50 were determined to be > 131 mg/L. The results are based on the nominal concentrations.

Executive summary:

The 72 hours ErC10 and ErC50 (growth rate), EyC10 and EyC50 (yield) of the test substance on Raphidocelis subcapitata was determined according to the principles of OECD 201 (2011) in a static growth inhibition test under GLP conditions. The aim of the study was the determination of NOEC, LOEC, EC10, EC20- and EC50-values of growth rate and yield over a period of 72 hours. Based on the results of range finding study, a limit test was conducted at the concentration of 131 mg/L. 6 replicates for each concentration and control were used. The algal growth (cell density) was assessed at 24, 48 and 72 hours post-exposure. Exponentially growing algae cells (5561 cells/mL) were exposed to the limit concentration of 131 mg/L. Due to the complexity of the test item, test concentration analysis was not performed, therefore all results are based on nominal values. A positive control with the reference substance 3, 5-dichlorophenol was performed obtaining a growth rate inhibition ErC50 of 1.60 mg/L and inhibition in yield EyC50 of 1.28 mg/L. This 72 hours growth rate inhibition and percent inhibition in yield lies within the validity criteria acceptance range and establishes the acceptability of test system response and test procedures followed. After 72 hours the NOEC was determined to be 131 mg/L. The ErC10 and the ErC50 were determined to be > 131 mg/L.