Resin acids and Rosin acids, barium salts

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:

2021

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Resin acids and Rosin acids, barium salts

EC Number:

269-142-0

EC Name:

Resin acids and Rosin acids, barium salts

Cas Number:

68188-14-7

Molecular formula:

N/A

IUPAC Name:

Resin acids and Rosin acids, barium salts

Test material form:

solid

Details on test material:

Specific details on test material used for the study
SOURCE OF TEST MATERIAL
- Batch number of test material: EXP NR.3757-01
- Expiration date of the lot/batch: 31 Dec 2029
STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: refrigerator
- Stability under storage conditions: The stability of the test substance under storage conditions is
guaranteed until 31 Dec 2029 as indicated by the sponsor, and the sponsor holds this responsibility.
- Stability under test conditions: no data

Specific details on test material used for the study:

Test substance No.: 19/0421-1
Batch identification: EXP NR.3757-01

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Details on test solutions:

The test solutions were prepared separately for each test concentration. The test substance was weighed into 1-L volumetric flasks and stirred on a magnetic stir plate for about 48 hours at room
temperature. Following, undissolved test substance was be removed by twofold filtration (fourfold for the 320 mg/L treatment) with a membrane filter (pore size 0.2 μm). The first 50-100 mL of the
filtered solutions were discarded (used to condition the filter). Solutions were inspected visually for the presence of any undissolved test substance by observing the scattering of a laser
light through the test solution (Tyndall effect). Following filtration, test solutions appeared clear and colorless, Tyndall effect was negative(a).
(a)All test solutions were visibly clear following preparation, except the 320 mg/L treatment, containing white particulates, presumably caused by abrasion of the filter material, while revealing a negative tyndall effect.

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

-Test species and strain: Desmodesmus subspicatus CHODAT (SAG 86.81)
- Age (on study day 0): A stock algal culture is maintained continuously at the test facility. Before the exposure an inoculum culture is prepared from the stock culture and incubated for 3 days at 21 – 24 °C (max. temperature difference 2 °C). After this time, the inoculum culture is in exponential growth phase and can be used to initiate the test (study day 0).
- Supplier: Collection of algal cultures in University of Göttingen/Germany

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: Erlenmeyer flasks (nominal volume 250 mL) plugged with gas permeable silicone sponge caps, 100 ml fill volume
- Initial cells density: 0.5 x 104 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6


GROWTH MEDIUM
- Standard medium used: yes

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16:8
- Light intensity and quality: Average 4900 lux (within ±15% variability) at a wave length of 400 - 700 nm

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

8.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

Some samples for analytical monitoring were filtered before analysis. The measured concentrations (geometric mean) of the main constituent of the test substance in the test water were in a range
of 35-77% of the nominal concentrations. This was most likely due to limited solubility of the test substance in the test medium, and an additional decrease of the test substance over 72 h. Moreover, the test substance is a UVCB and as such every constituent contributes to a different degree to overall solubility, depending on its own individual solubility and its mass fraction in the test substance. Thus, for an evaluation of the results the nominal concentrations should be used and were considered to be an accurate representation of exposure levels throughout the experiment.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes