2-isobutyl-4-methyltetrahydro-2H-pyran-4-yl acetate

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 study according to OECD guideline

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

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:

2-isobutyl-4-methyltetrahydro-2H-pyran-4-yl acetate

EC Number:

942-380-9

Cas Number:

131796-64-0

Molecular formula:

C12H22O3

IUPAC Name:

2-isobutyl-4-methyltetrahydro-2H-pyran-4-yl acetate

Details on test material:

- Name of test material (as cited in study report): pyranyl acetate pure
- Physical state: Colourless to yellowish, clear, liquid
- Analytical purity: 99.0 corrected area-%
- Lot/batch No.: ZH 146
- Expiration date of the lot/batch: December 2015
- Stability under test conditions: Hydrolysis half-lives: 1088. 7 h (pH 4, 50 °C),
5800.9 h (pH 9, 20 °C) (BASF study no 15L00024)
- Storage condition of test material: Ambient (room temperature)

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

-Analytical evaluation of the test concentrations of pyranyl acetate pure and the control was carried out via LC-MS/MS from freshly
prepared media after 0 hours and old test media after 72 hours.
Samples for the test item analysis at the beginning of the exposure were taken from an additionally prepared replicate with algae. For the test item analysis after 72 hours, samples were taken out of the test replicates.
- Sample storage conditions before analysis: All samples were stored at room temperature until preparation, if
necessary. Prepared samples were stored at room temperature (autosampler) until analysis.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- The stock solution of 120 mg/L was freshly prepared with dilution water
and gently agitated until the solution was clear.

Test organisms

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchnerie/la subcapitata HINDAK, SAG 61.81
- Source (laboratory, culture collection): Sammlung von Algenkulturen (SAG)
Pflanzenphysiologisches lnstitut der Universitat Gottingen Nikolausberger Weg 18, D-37073 Gottingen
- Age of inoculum (at test initiation): A three days old preculture, prepared in dilution water, was used as inoculum. For the start of the test, the preculture was directly pipetted into each test medium and the control.
- Cultivation at test facility: Fresh stocks are prepared every month on Z-Agar. Light intensity amounted to 35 - 70 μE · m-2 · s-1 for 24 hours per day.

ACCLIMATION
- Culture medium: Nutrient medium Z according to LOTTGE et al. (1994)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Hardness:

22.3 CaC03 mg/L

Test temperature:

21.5 - 22.5 °C

pH:

7.82-9.01

Nominal and measured concentrations:

Nominal concentrations: control, 120, 60, 30, 15, 7.25 mg/L
Measured concentrations: control, 132, 55.8, 29.7, 14.2, 7.42, mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Sterile Erlenmeyer flasks (vol. 250 ml) with cotton wool plugs.
- Test volume: 100 ml
- Initial cells density: Nominal: approximately 5 x 103 - 104 cells/mL, Actual: 6.153 x 103 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 LOTTGE et a/. (1994)


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: According to the guidelines

OTHER TEST CONDITIONS

- Adjustment of pH: no
- Photoperiod: 24 hours/day light
- Light intensity and quality: Approximately 60 - 120 μE · m-2 · s-1


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: The cell density was measured daily via Chlorophyll afluorescence,
excitation at 436 nm, emission at 685 nm. Dilution water was used as background signal.

TEST CONCENTRATIONS
5 concentrations were tested in a geometrical series with a dilution factor of 2: 7.25 - 15.0 - 30.0 - 60.0 - 120 mg/L.
The concentrations were based on the results of a preliminary range finding test.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

17.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

27.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

74.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Results with reference substance (positive control):

EC50 based on nominal concentrations (mg/L], (0-72 hours): 0.613
95 % confidence interval: 0.589 - 0.638

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In this study, pyranyl acetate pure was found to inhibit the growth of the freshwater green alga
Pseudokirchneriella subcapitata over the period of 72 hours. The ECso-value for inhibition of
specific growth rate (ErCso) after 72 hours was 74.6 mg test item/L, the EC20- and EC10-values
were determined to be 27. 7 and 17.1 mg test item/L, respectively.
All effect values are based on nominal concentrations of the
test item.