1,3-difluorobenzene

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

Test material information

Constituent 1

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.