Boric acid (H3BO3), solid soln. with strontium oxide, europium-doped

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:

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)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Boric acid (H3BO3), solid soln. with strontium oxide, europium-doped

EC Number:

310-028-8

EC Name:

Boric acid (H3BO3), solid soln. with strontium oxide, europium-doped

Cas Number:

102110-29-2

Molecular formula:

SrB4O7:Eu

IUPAC Name:

Boric acid (H3BO3), solid soln. with strontium oxide, europium-doped

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Sponsored by ZHEJING JINGNENG PHOSPHOR MATERIAL CO., LTD. ; 170825
- Expiration date of the lot/batch: 24 Aug 2019
- Purity: 99%


STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room Temperature, protected from light
- Stability under test conditions: not specified
- Solubility and stability of the test substance in the solvent/vehicle: Insoluble in water, soluble in the inorganics acid


TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: The test item has been prepared at 1000 mg/L, 100 mg/L and 10 mg/L in culture medium. The solutions have been extracted for 72 h at room temperature. From extract at 10 mg/L two solutions have been prepared (1 mg/L and 0.1 mg/L) under stirring.
- Final dilution of a dissolved solid, stock liquid or gel: ten-fold dilutions

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test item has been prepared at 1000 mg/L, 100 mg/L and 10 mg/L in culture medium. The solutions have been extracted for 72 h at room temperature. From extract at 10 mg/L two solutions have been prepared (1 mg/L and 0.1 mg/L) under stirring.
- Controls: Culture medium

Test organisms

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchneriella subcapitata
- Strain: subcapitata
- Age of inoculum (at test initiation): not specified


ACCLIMATION
- Culturing media and conditions (same as test or not): same as test
- Any deformed or abnormal cells observed: none

Study design

Test type:

static

Water media type:

other: culture medium

Limit test:

yes

Total exposure duration:

72 h

Remarks on exposure duration:

By steady stirring at 23°C + 2°C under continuous light( with fluorescent lamp 8000 lux) for 72 + 2 hours.

Test conditions

Test temperature:

23 ± 2°C

pH:

7.7-8.0

Nominal and measured concentrations:

Range finding test: 1000 mg/L, 100 mg/L, 10 mg/L, 1 mg/L and 0.1 mg/L
Definitive test: 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- Material, size, headspace, fill volume: Glass, 250 ml
- Aeration: not specified
- Renewal rate of test solution (frequency/flow rate): static
- Initial cells density: 10000 cell/mL
- Control end cells density: 10000 cell/mL
- No. of organisms per vessel: 10000 cell/mL
- No. of vessels per concentration (replicates):6
- No. of vessels per control (replicates):10000 cell/mL
- No. of vessels per vehicle control (replicates):6

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The culture medium has been used as dilution water
- Culture medium different from test medium: no


OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Photoperiod: Continuous
- Light intensity and quality: with fluorescent lamp 8000 lux


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: Burker chamber


TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 1000 mg/L, 100 mg/L, 10 mg/L, 1 mg/L and 0.1 mg/L
- Results used to determine the conditions for the definitive study:After the results of the range finding test, a limit test has been performed.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Basis for effect:

growth rate

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): yes
- Unusual cell shape:not specified
- Colour differences: not specified
- Flocculation: not specified
- Aggregation of algal cells: not specified
- Any stimulation of growth found in any treatment: not specified
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values:not specified

Reported statistics and error estimates:

No deviation has been detected during the study.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

- Cell concentration(control ) increased at least 16(factor) within three days and specific growth rate of 0.92 day -1. - CVss specific growth rates in the control cultures must not exceed 35%. -CVwp in replicate control cultures must not exceed 7%.

Conclusions:

The obtained results, in compliance with assay validity criteria, showed that Algae EC50 of the nominal concentration of the test item “Boric acid (H3BO3), solid soln. with strontium oxide, europium-doped” after 72 hours is > 100.00 mg/L.

Executive summary:

In a 72 hour acute toxicity study according to the guideline of OECD 201 , the cultures of Pseudokirchneriella subcapitata exposed to Boric acid (H3BO3), solid soln. with strontium oxide, europium-doped. During the range finding test, the algae have been exposed to 5 different dilutions of the test item(1000, 100, 10, 1, 0.1 mg/L ) for 72 hours. After the results of the range finding test a limit test (100 mg/L) has been performed.The EC₅₀ values based on cell density were more than 100 mg/L. 

 

This toxicity study is classified as acceptable and satisfies the guideline requirements for Pseudokirchneriella subcapitata toxicity study.

 

Results Synopsis

 

Test Organism: Green alga

Test Type (Flowthrough, Static, Static Renewal): static

 

72.hr EC₅₀:  ＞ 100 mg /L