p-benzoquinone

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

Study period:

02.04.2018-27.04.2018

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)

Deviations:

no

GLP compliance:

no

Remarks:

accredited by DAkkS

Test material

Test material information

Constituent 1

Reference substance name:

p-benzoquinone

EC Number:

203-405-2

EC Name:

p-benzoquinone

Cas Number:

106-51-4

Molecular formula:

C6H4O2

IUPAC Name:

1,4-benzoquinone

Test material form:

solid: particulate/powder

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

not specified

Details on test solutions:

The test vessels contained a final volume of 10 mL (p-benzoquinone stock solution and dilution water). For each dilution stage and a control solution (contains only water) four 30 mL-test tubes with 5 daphniae were prepared. The test tubes were covered with Kapsenberg caps and left for 48 h. Incubation was performed at room temperature (20-22°C) in a 12 h/12 h light-dark rhythm without feed portion. The daphnia mobility was checked and documented after 24 h and 48 h.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna Straus

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Test temperature:

20-22°C

pH:

7,6 (+/-0,2)

Dissolved oxygen:

8,5 (+/-0,2) in the beginning of the test
7,6 (+/-0,1) in the end of the test

Salinity:

dilution water:
25 ml 0,08 M CaCl2-solution
+ 25 ml 0,02 M MgSO4-solution
+ 25 ml 0,03 M NaHCO3-solution
+ 25 ml 0,003 M KCl in 1 L deionised water

Conductivity:

606 μS/cm (dilution water)

Nominal and measured concentrations:

0,05 mg/l, 0,10 mg/l, 0,15 mg/l, 0,20 mg/l, 0,25 mg/l

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.13 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

A daphnia is assessed as immobile provided that it did not move independently or after slight swinging 15 s as a minimum. Other effects of the test substance on daphniae like coloration or special stress behaviour were not observed.

Any other information on results incl. tables

The relevant concentration range for the calculation of the EC₅₀-value was determined in preliminary tests.

Tab. 1: Mobility of Daphnia magna Straus at different p-benzoquinone concentrations

concentration [mg/l]	Mobility of Daphnia magna after
	24 h		48 h
	Amount	%	Amount	%
0,05	20	100	20	100
0,10	18	90	17	85
0,15	10	50	8	40
0,20	6	30	4	10
0,25	0	0	0	0

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

Reference samples did not fall below 90% daphnia mobility. Oxygen content at the test end was always above 3 mg/L.

Conclusions:

In a study according to OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test), a 48 h EC50 = 0,13 mg/L for p-benzoquinone was determined.

Executive summary:

The acute toxicity of p-benzoquinone to Daphnia magna was investigated in a study according to OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test) under static conditions. The endpoint examined was immobilization. The daphnids (5 animals/concentration) were exposed to nominal concentrations of 0,05 mg/l, 0,10 mg/l, 0,15 mg/l, 0,20 mg/l and 0,25 mg/l p-benzoquinone.

The 48 h EC50 was determined to be 0,13 mg/L based on nominal concentrations.

The testing/validity criteria laid down in the OECD guideline 202 are fulfilled. This study is regarded as reliable without restriction.

Thus, a 48 h EC50=0.13 mg/L (recalculated based on initial concentrations) has to be taken into account for the assessment.