2,3-dichlorobenzaldehyde

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:

2016

Report date:

2016

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2,3-dichlorobenzaldehyde

EC Number:

228-711-3

EC Name:

2,3-dichlorobenzaldehyde

Cas Number:

6334-18-5

Molecular formula:

C7H4Cl2O

IUPAC Name:

2,3-dichlorobenzaldehyde

Test material form:

solid: crystalline

Details on test material:

Test item: 2,3-dichlorobenzaldehydeCas No.: 6334-18-5Storage: 15-30 °C

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Details on test solutions:

Preparation of stock solution:The preparation of stock and test solutions was based on the preliminary non GLP range finding test. For the stock solution 40.06 mg of test item was measured into 1 000 ml OECD medium. The suspension were stirred and ultrasonicated till complete dilution of test item. The stock solution was clear and colourless. The concentration of stock solutions was determined by validated HPLC method. The measured concentration was 36.25 mg/L.Preparation of test solutions:Seven test solutions of different concentration were prepared by mixing appropriate volume of OECD medium and stock solution of the test item. These concentrations were arranged in a geometric series with a maximum separation factor 2.0. Three additional replicates were prepared for controlling the abiotic degradation of the test substance. These test vessels were not inoculated with alga inoculum culture. The volume of the prepared dilution levels was 300 ml except the control solution which was 600 ml.

Test organisms

Test organisms (species):

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

Details on test organisms:

Test species: Pseudokirchneriella subcapitata (Korshikov) F.Hindák(formerly known as Selenastrumcapricornutum)Source: UTEX The Culture Collcetion of Algae (USA)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test conditions

Test temperature:

The temperature inside the incubator at the test vessels was measured and registered continuously by thermometer and datalogger. Throughout the test the temperature was nearly constant.The temperature during the test remained in the 21 ± 2 °C range.

pH:

At the beginning of the test the pH values were measured in the remaining test solution of the concurrent test vessels at each dilution level. At the end of the test the pH values were measured in each test vessel. The pH of test solutions was not adjusted at the beginning of the test.

Nominal and measured concentrations:

The nominal concentration of the stock solution was 40 mg/L. In the test the following nominal concentrations were applied: 40; 24; 16; 10; 8; 4 and 2 mg/L.The following concentrations were calculated from the measured/calculated values in the test: 27.013; 15.937; 9.394; 2.431; 0.629; 0.443 and 0.304 mg test item/L.

Details on test conditions:

The test vessels were closed with silicone stopper and kept in incubator. For the proper mass transfer of carbon dioxide glass tubes with filter were placed trough silicone stoppers. The test was maintained under static conditions for a period of 72 hours. The vessels were shaken and illuminated continuously in the incubator. The vessels were placed randomly into the incubator and were repositioned daily after sampling. One of the vessels of abiotic controls was taken into the incubator with a complete aluminium foil cover to check the stability of test item in the absence of light.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.782 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

1.232 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

2.942 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

0.629 mg/L

Conc. based on:

test mat.

Effect concentrations 5

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.443 mg/L

Conc. based on:

test mat.

Details on results:

The values of LOEC and NOEC were calculated by ToxRat® statistic software.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

According to the Council Regulation (EC) 440/2008 2,3-Dichloro-benzaldehyde is hazardous to the aquatic environment and classified into the second acute toxic hazardous category [GHS Acute aquatic hazard Category Acute II. – 72 hr EC50 (for algae or other aquatic plants) > 1 mg/L but ≤ 10 mg/L].