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Ecotoxicological information

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
Study period:
2018-04-13 - 2018-04-26
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:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid
Specific details on test material used for the study:
Molecular formula: HOCH2C(Br)=C(Br)CH2OH
Molecular Mass: 245.91 g/mol
Characteristics (Physical Appearance):
White crystalline powder
CAS No.:
3234-02-4
Batch Number:
1088
Purity:
100% by GC

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no
Details on test solutions:
100 mg of trans-2,3-dibromo-2-butene-1,4-diol was suspended in OECD media to prepare a stock solution of a final volume of 10 ml, with a nominal concentration of 10 mg/ml. This stock was suitably added to test containers to attain the desired test concentration.

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
Test species:
Unicellular green alga, Pseudokirchneriella subcapitata (Selenastrum capricornutum)
Justification for selection of species:
Species recommended by OECD Guideline No. 201.
Strain:
ATCC-22662
Source:
Procured from American Type Culture Collection (ATCC) and maintained at INTOX PVT. LTD.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
72 h

Test conditions

Test temperature:
25.2 to 25.5 0C.
pH:
7.59 to 8.20 (0 hour to 72 hours)
Reference substance (positive control):
yes
Remarks:
Potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Growth inhibition Test of trans-2,3-dibromo-2-butene-1,4-diol in fresh water green alga -Pseudokirchneriella subcapitata (Selenastrum capricornutum) was performed in compliance with the OECD Guideline for Testing of Chemicals, Section 2, No. 201, ‘Freshwater Alga and Cyanobacteria, Growth Inhibition Test’, adopted by the Council on 23 March 2006 and Annex 5 corrected: 28 July 2011.
The ErC50 (72 hours) value of trans-2,3-dibromo-2-butene-1,4-diol in fresh water unicellular green alga - Pseudokirchneriella subcapitata is estimated to be greater than 100 mg/L.
The EyC50 (72 hours) value of trans-2,3-dibromo-2-butene-1,4-diol in fresh water unicellular green alga - Pseudokirchneriella subcapitata is estimated to be greater than 100 mg/L.
Executive summary:

Growth inhibition Test of trans-2,3-dibromo-2-butene-1,4-diol in fresh water green alga -Pseudokirchneriella subcapitata (Selenastrum capricornutum) was performed in compliance with the OECD Guideline for Testing of Chemicals, Section 2, No. 201, ‘Freshwater Alga and Cyanobacteria, Growth Inhibition Test’, adopted by the Council on 23 March 2006 and Annex 5 corrected: 28 July 2011.

trans-2,3-dibromo-2-butene-1,4-diol was tested for its possible inhibitory effect on growth of alga, Pseudokirchneriella subcapitata. Exponentially growing cultures of the algae were exposed to test item at concentration of 100 mg/L for a period of 72 hours, along with a concurrent blank control group. Potassium dichromate, used as a reference item, was also concurrently tested at concentrations of 0.4, 0.8 and 1.6 mg/L. The cell concentration, i.e. the number of cells per ml, for all the concentrations, was counted at 24, 48 and 72 hours of the exposure by counting them under microscope in a haemocytometer counting chamber and the inhibition of growth in relation to the control culture was determined.

Percent inhibition of growth rate in fresh water unicellular green alga, Pseudokirchneriella subcapitata at 72 hours, was 3.36 recorded at the concentration of 100 mg/L. In reference item group percent inhibition of growth rates in fresh water unicellular green alga, Pseudokirchneriella subcapitata at 72 hours, were 18.16, 46.83 and 96.71 recorded at the concentrations of 0.4, 0.8 and 1.6 mg/L respectively.

Percent inhibition in yield in fresh water unicellular green alga, Pseudokirchneriella subcapitata at 72 hours, was 9.58 recorded at the concentrations of 100 mg/L respectively. In reference item group percent yield in fresh water unicellular green alga, Pseudokirchneriella subcapitata at 72 hours was 42.61, 77.90 and 99.36 recorded at the concentrations of 0.4, 0.8 and 1.6 mg/L respectively.

The ErC50 (72 hours) value of trans-2,3-dibromo-2-butene-1,4-diol in fresh water unicellular green alga - Pseudokirchneriella subcapitata is estimated to be greater than 100 mg/L.

The EyC50 (72 hours) value of trans-2,3-dibromo-2-butene-1,4-diol in fresh water unicellular green alga - Pseudokirchneriella subcapitata is estimated to be greater than 100 mg/L.