2-methylhydroquinone

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19.02.2018-21.03.2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

no

Remarks:

accredited by DAkkS

Analytical monitoring:

not specified

Vehicle:

yes

Remarks:

test samples diluted in water

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 (species):

Daphnia magna

Details on test organisms:

Daphnia magna Straus

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20-22°C

pH:

7,6 (+/-0,4)

Dissolved oxygen:

8,6 (+/-0,4) in the beginning of the test
7,6 (+/-0,6) 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:

0,20 mg/l, 0,25 mg/l, 0,30 mg/l, 0,40 mg/l, 0,50 mg/l, 0,60 mg/l

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.35 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.

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 methylhydroquinone concentrations

concentration [mg/l]	Mobility of Daphnia magna after
	24 h		48 h
	Amount	%	Amount	%
0,20	20	100	20	100
0,25	18	90	16	80
0,30	14	70	12	60
0,40	16	80	8	40
0,50	10	50	4	20
0,60	4	20	0	0

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 = 0,35 mg/L for methylhydroquinone was determined.

Executive summary:

The acute toxicity of methylhydroquinone 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 0,20 mg/l, 0,25 mg/l, 0,30 mg/l, 0,40 mg/l, 0,50 mg/l and 0,60 mg/l methylhydroquinone.

The 48 h EC50 was determined to be 0,35 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 = 0,35 mg/L (recalculated based on initial concentrations) has to be taken into account for the assessment.

Description of key information

In a study according to OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test), a 48 h EC50 = 0,35 mg/L for methylhydroquinone for daphnia magna was determined.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

0.35 mg/L