Benzenemethanaminium, N,N,N-trimethyl-, 2-hydroxy-2-methylpropanoate (1:1)

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guidline Study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

benzyltrimethylazanium 2-hydroxy-2-methylpropanoate

EC Number:

805-580-6

Cas Number:

1431696-36-4

Molecular formula:

C14 H23 O3 N

IUPAC Name:

benzyltrimethylazanium 2-hydroxy-2-methylpropanoate

Details on test material:

- Identification: BTMA-HIB
- Chemical name: N,N,N-trimethyl -, 2-hydroxy- 2-methylpropanoate (1:1)
- Physical form: Solid
- Water solubility: Miscible
- Purity: >90%; treated as 100% pure
- Storage: at room temperature, under N2

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

HPLC analyses of the test substance concentrations were conducted in the
definitive test at the beginning of the test and after 24, 48 and 72 h of exposure.

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

- Common name: Desmodesmus subspicatus
- Strain: SAG 86.81
- Source (laboratory, culture collection): Collection of algal cultures in University of Göttingen/Germany
- Age of inoculum (at test initiation): The axenic slope culture is yearly re-purchased. Potassium dichromate is used to control the sensitivity of the culture twice a year.
- Method of cultivation: 250 ml flask containing 100 ml of sterile OECD medium inoculated with cell material from axenic slope cultures; Continuous illumination (2000–3000 lux) from Osram Fluora L18W77 and Osram Daywhite L18W840 (Osram AG, Winterthur, Switzerland); 22 ± 2 °C, thermo-controlled room

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

22 ± 2°C

pH:

7.2-7.8

Dissolved oxygen:

Not measured

Salinity:

Not measured, freshwater

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL flasks
- Material, size, headspace, fill volume: 250 mL Erlenmeyer flasks, test volume 100 mL
- Shaking rate: continuous (appr. 130 rpm)
- Type of flow-through (e.g. peristaltic or proportional diluter): None
- Renewal rate of test solution (frequency/flow rate): One application at test start
- Initial cells density: 0.5x10^4 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6
- No. of vessels per test group for estimating initial concentration control analsis only (replicates): 3
- No. of vessels per blank control for estimating initial concentration: 6


GROWTH MEDIUM
- Standard medium used: yes


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: OECD medium prepared according to OECD Guidleine for Testing of Chemicals, No. 201 Algal growth inhibition test, Mar 2006, Annex 5 corrected July 2011
- pH-value: The pH of the control medium should not increase by more than 1.5 units during the test. Determined in the medium batch which is used for the preparation and dilution of the stock solution
- Starting cell density: 0.50–0.85 μg/ml with respect to dry weight corresponding to about 2–5•103 cells/ml (i.e. OD680 of about 0.005 units)

OTHER TEST CONDITIONS
- Sterile test conditions: no
- Adjustment of pH: no
- Photoperiod: Source: continuous from Osram Fluora L 18W77 and Osram Daywhite L 18W840 (Osram AG, Winterthur, Switzerland);
- Light intensity and quality: Light intensity (target): the light intensity amounts to about 3000 lux which corresponds to about 40 μE•m-2•s-2 according to the OECD TG no. 2011; Homogeneity (target): the light intensity is maintained within ±15% from the average light intensity over the incubation area


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Observation: Cell concentrations were determined every 24 h using a spectrophotometer (680 nm wavelength). Aliquots of 5 ml were removed from each test flask under sterile conditions. Cell concentrations at time 0 h were only determined in the control vessels
- Chemical analysis: The chemical analysis of EMIM Dicyanamid was performed with a combined approach. The cation (1H-imidazolium, 1-ethyl-3-methyl-) was measured by HPLC. Additionally, EMIM Dicyanamid was measured by dissolved organic carbon (DOC) determinations. Both analysis were conducted in the definitive test at the beginning, and after 24, 48 and 72 h of exposure.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

198 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 189-207

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

49.4 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 43.7-55.0

Applicant's summary and conclusion

Validity criteria fulfilled:

yes