Permanganic acid

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:

20. October - 22. October 2020

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:

yes

Remarks:

Instead of standard M4 medium, water treated with salts (specification given below) was used. This change is in line with the OECD guideline for testing metals. As no detrimental effects were observed, the deviations can be considered uncritical.

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on test solutions:

For testing the following specification was used (instead of standard M4 medium):
293.8 mg/L CaCl2*2H2O, 123.3 mg/L MgSO4*7H2O, 64.8 mg/L NaHCO3 and 5.8 mg/L KCl

Deviations from the nominal weighted loads were less than 5 % during preparation. After preparation, the dilution water was aerated and the pH was measured. The pH was 7.6.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: Strauss Berlin
- Justification for species other than prescribed by test guideline: -
- Age at study initiation (mean and range, SD): between 0 and 24 hours
- Method of breeding: parthenogenesis
- Source: Umweltbundesamt Berlin
- Age of parental stock (mean and range, SD): -
- Feeding during test
- Food type: -
- Amount: -
- Frequency: -

ACCLIMATION
- Acclimation period: no
- Acclimation conditions (same as test or not): -
- Type and amount of food: -
- Feeding frequency: -
- Health during acclimation (any mortality observed): no

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20.3 – 20.7 °C

pH:

7.8 - 7.9

Dissolved oxygen:

8.3 - 8.9

Salinity:

-

Nominal and measured concentrations:

nominal: 0.46 / 1 / 2.2 / 4.6 / 10 mg/L (related to test item)
geometric measured mean: 0.016 / 0.027 / 0.071 / 0.144 / 0.276 mg/L (related to permanganic acid)

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers, nominal volume 50 mL, tall shape
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass, ca. 30 mL headspace, 20 ± 5 mL fill volume
- Volume of solution:
- Aeration: -
- Type of flow-through (e.g. peristaltic or proportional diluter): -
- Renewal rate of test solution (frequency/flow rate): none
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): -
- Biomass loading rate: -

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: demin. water; additional information under 'details on test solutions'
- Total organic carbon: -
- Particulate matter: -
- Metals: -
- Pesticides: -
- Chlorine: -
- Alkalinity: -
- Ca/mg ratio: approx 3:1
- Conductivity: -
- Salinity: -
- Culture medium different from test medium: yes (standard M4 medium for culture)
- Intervals of water quality measurement: -

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16/8 hours, using LED’s
- Light intensity: not given

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobilisation (24 / 48 h)

VEHICLE CONTROL PERFORMED: no

RANGE-FINDING STUDY (non-GLP range finder was performed)
- Test concentrations: not stated
- Results used to determine the conditions for the definitive study: not stated

Reference substance (positive control):

yes

Remarks:

Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9) was used as positive control in a cur-rent reference study to assure that the test conditions are reliable.

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

0.039 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

element

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.044 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

element

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.027 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

element

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

0.071 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

element

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: no
- Observations on body length and weight: -
- Other biological observations: no
- Mortality of control: no
- Other adverse effects control: -
- Immobilisation of control: no
- Abnormal responses: -
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No undissolved particles were visible in all test solutions throughout the test
- Effect concentrations exceeding solubility of substance in test medium: none

Results with reference substance (positive control):

not stated

Reported statistics and error estimates:

Statistics were calculated with ToxRat Professional (V.3.3.0). Confidence interval was not calculated.

Nominal Concentration in mg/L	Geometric Mean Concentration in mg/L	Immobility 24 hours					Immobility 48 hours
		absolute				in %	absolute				in %
Blank control	--	0	0	0	0	0	0	0	0	0	0
0.46	0.016	0	0	0	0	0	0	0	0	0	0
1	0.027	0	0	0	0	0	0	0	0	0	0
2.2	0.071	5	5	5	5	100	5	5	5	5	100
4.6	0.144	5	5	5	5	100	5	5	5	5	100
10	0.276	5	5	5	5	100	5	5	5	5	100

Validity criteria fulfilled:

yes

Remarks:

no immobilisation in controls was observed; the lowest concentration of dissolved oxygen at the end of the test was 8.3 mg/L (limit 3 mg/L).

Conclusions:

The dose-response relationship was extremely steep. An effect concentration EC50 (48 h) of 0.044 mg/L was determined in this study.

Executive summary:

The study was performed using 5 concentrations ranging from 0.46 to 10 mg/L nominal concentration. For each test concentration and the blank control, 20 daphnia were exposed to the test item for 48 hours in a static test system. After 24 and 48 hours, the immobilised daphnia were counted.

The dose-response relationship was extremely steep. The three highest concentrations showed toxicity of 100 % immobilisation. None of the animals was immobilised in the blank control and the lower concentrations.

 

Potassium dichromate K₂Cr₂O₇(CAS No. 7778-50-9) was used as positive control in a current reference study to assure that the test conditions are reliable.

 

At the beginning and at the end of the test, the content of Manganese (Mn) as component of the test item in the test solutions was determined using ICP-OES-determination. The concentrations determined at the start of the test lay between 99 % and 112 % of the nominal concentrations and between 55 % and 99 % of the nominal concentrations at the end of the test. Therefore, the determination of the results was based on the geometric mean of the measured concentrations (see OECD 202 (§ 23)).

 

No observations were made which might cause doubts concerning the validity of the study outcome. All validity criteria were met.

The result of the test is considered valid.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.044 mg/L