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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
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 202 (Daphnia sp. Acute Immobilisation Test)
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
1,3-difluorobenzene
EC Number:
206-746-5
EC Name:
1,3-difluorobenzene
Cas Number:
372-18-9
Molecular formula:
C6H4F2
IUPAC Name:
1,3-difluorobenzene

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
yes

Test organisms

Test organisms (species):
Daphnia magna

Study design

Test type:
static
Water media type:
brackish water
Limit test:
yes
Total exposure duration:
48 h

Test conditions

Hardness:
149.3 to 183.2 mg.L-1 CaCO3
Test temperature:
20.1 to 20.3°C
pH:
7.7 to 7.8
Dissolved oxygen:
8.1 mg.L-1
Reference substance (positive control):
yes

Results and discussion

Effect concentrations
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Details on results:
This study was carried out in order to evaluate the acute toxicity of 1,3 - Difluorobenzene to Daphnia magna. A range-finding test was carried out to determine the concentrations that caused 100% and 0% of acute toxic effect. According to the results obtained in the range-finding test, a definitive test was carried out with only the maximum concentration of 100 mg.L-1. A control was also added. Twenty organisms were used per concentration and control distributed into four replicates. The definitive test was conducted in a controlled environment with temperature ranging from 20.1 to 20.3°C, for 48 hours with photoperiod of 16 hours light and 8 hours of dark. The 48-hours EC50 value was not determined because the highest tested concentration of 1,3 - Difluorobenzene, 100 mg.L-1, did not cause immobility to the test organisms. Therefore the EC50 value of the tested substance is higher than 100 mg.L-1.

Any other information on results incl. tables

Table 4 -Number of Immobile Organisms at 24 and 48 Hours of Exposure, During the Range-  Finding Test.

                                  

Test

concentration (nominal)

 

(mg.L-1)

Number of immobile organisms

24 hours

48 hours

a

 

b

 

 

% of total immobility

in 24 hours

 

0

a

 

b

 

% of total immobility

in 48 hours

100

0

0

0

0

0

0

10

0

0

0

0

0

0

1

0

0

0

0

0

0

0.1

0

0

0

0

0

0

Control

0

0

0

0

0

0

 

a and b = replicates with 5 organisms each.

 

 

Table 5 - Number of Immobile Organisms at 24 and 48 Hours of Exposure, During the Definitive Test.

 

 

Test

concentration

(nominal)

(mg.L-1)

Number of immobile organisms

24 hours

48 hours

 

a

 

b

 

c

 

d

 

 

% of

total 

immobility

in 24 hours

 

 

a

 

b

 

c

 

d

 

 

% of

total 

immobility

in 48 hours

 

100

0

0

0

0

0

0

0

0

0

0

Control

0

0

0

0

0

0

0

0

0

0

 

a, b, c and d = replicates with 5 organisms each.


Table 6 -Number of Immobile Organisms at 24 Hours of Exposure, During the Test with the Reference Substance.

 

 

Concentration

(mg.L-1)

Number of immobile organisms

24 hours

 

a

 

b

 

c

 

d

 

 

% of

total 

immobility

in 24 hours

 

2.4

5

5

5

5

100

1.8

5

4

5

5

95

1.0

2

2

3

2

45

0.56

1

0

0

0

5

0.32

0

0

0

0

0

Control

0

0

0

0

0

 

a, b, c and d = replicates with 5 organisms each.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
the 48-hours EC50 value of the tested substance is higher than 100 mg.L-1.