Reaction mass of 3-methyl-1-octylpyridinium chloride and 4-methyl-1-octylpyridinium chloride

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 guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2015

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of 3-methyl-1-octylpyridinium chloride and 4-methyl-1-octylpyridinium chloride

EC Number:

941-484-1

Molecular formula:

not possible

IUPAC Name:

Reaction mass of 3-methyl-1-octylpyridinium chloride and 4-methyl-1-octylpyridinium chloride

Test material form:

liquid: viscous

Sampling and analysis

Analytical monitoring:

yes

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Strain: Desmodesmus subspicatus CHODAT SAG 86.81 (formerly Scenedesmus subspicatus CHODAT)
- Source (laboratory, culture collection): 'Sammlung von Algenkurturen', Göttingen (SAG), (Collection of Algae Cultures, Institute for Plant Physiology), University of Göttingen, Germany
- Method of cultivation: Fresh stocks were prepared every month on Z-Agar. Light intensity amounted to 35 - 70 µE·m-2 x s-1 for 24 h per day.

Study design

Test type:

static

Water media type:

freshwater

Total exposure duration:

72 h

Test conditions

Hardness:

This medium has a nominal hardness of 0.24 mmol Ca+Mg/L.

Test temperature:

Nominal range: 21 - 24 °C, controlled at ± 2 °C

pH:

7.80 - 8.47

Nominal and measured concentrations:

nominal (mg/L): 4.00, 1.6, 0.64, 0.256, 0.102
The measured test item concentrations were all within ± 20 % of the nominal concentrations.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: all Sterile Erlenmeyer flasks of 250 mL volume filled with 100 mL test medium
- Aeration: no
- Initial cells density: Nominal: approximately 5 x 10^3 - 10^4 cells/mL Current: 4998 cells/mL

- Control end cells density (mena): 551691 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: Nutrient medium Z according to LÜTTGE et al. (1994)

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: double distilled water
- Total organic carbon: NaHCO3 50 mg/L
- Ca/mg ratio:of 0.24 mmol Ca+Mg/L
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: no. The pH-value at the beginning of the test was measured in one additional replicate per concentration level and control. At the test end, it was measured from pooled replicates per test item concentration and control, respectively.
Photoperiod: 24 hours/day light
- Light intensity: 60 - 120 µE · m-2 · s-1

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): algal cell concentration determined by photometric measurement after 0, 24, 48 and 72 h
- Determination of cell concentrations: Chlorophyll a-fluorescence, excitation at 436 nm, emission at 685 nm.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: The measured test item concentrations were all within ± 20 % of the nominal concentrations.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.611 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95 % confidence interval: 0.523-0.713

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

1.45 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95 % confidence interval: 0.137-1.54

Effect concentrations 3

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.256 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.436 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: yield

Remarks on result:

other: 95 % confidence interval: 0.274-0.586

Effect concentrations 5

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.679 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: yield

Remarks on result:

other: 95 % confidence interval: 0.469-1.08

Effect concentrations 6

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.256 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: yield

Details on results:

- Observation of abnormalities (for algal test): unusual observations were not made
- Any stimulation of growth found in any treatment: growth and yield of the algae was increased at concentrations of 0.256 mg/L
- 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
- EC50: 0.586 mg/L (growth rate)

Any other information on results incl. tables

The validation criteria were fulfilled as algal growth in the control between 0 and 72 h exceeded the factor of 16 as requested by the underlying OECD guideline.With the current test it was found to be 111. The mean coefficient of variation of the section-by-section (0 - 24, 24 - 48 and 48 – 72 h) growth rate in the control cultures must not exceed 35% and it was 17.5% in the current test.

The coefficient of variation of the average specific growth rate in the control cultures, measured during the exposure period (0-72 h) must not exceed 7% and it was 3.81% in the current test.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In this study, the test item was found to inhibit the growth of the freshwater green alga Desmodesmus subspicatus after 72 hours with the
following effect values: The NOEC-value for growth rate after 72 hours was 0.256 mg/L. The EC50-value for inhibition of growth rate (ErC50) with 95 % confidence intervals after 72 hours was determined to be 1.45 (1.37 – 1.54) mg/L.