Dibutyl peroxydicarbonate

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:

2018-30-19 to 2018-07-16

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)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Substance specific analysis is performed without GLP at the analytical laboratory WeylChem InnoTec GmbH Business Unit Analytics (Alt-Fechenheim 34, D-60386 Frankfurt am Main). Of each sampled treatment, one of the samples from 0 h, 24 h and 48 h is sent to the analytical
laboratory for chemical analysis, according to their specification.
- Test item loading rate (mg/L): 0.0 (Sample code: NC), 0.34 (Sample code: A), 0.75 (Sample code: B), 1.65 (Sample code: C), 3.64 (Sample code: D), 80 (Sample code: E)
- Sampling method: After 0 h, 24 h and 48 h exposure, all replicates of NC, A, B, C, D and E are sampled; one sample per replicate: 4 samples of 8 mL per treatment group.
- Sample storage conditions before analysis: The samples are filled into 12 mL glass vials and stored in the freezer (≤ -18 °C).

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The stock solution is prepared by adding 90.9 μL (corresponds to 80 mg; density 880 mg/cm³) test item to 1000 mL test medium and shaking for ca. 24 h using an overhead shaker at room temperature in the dark. Subsequently, the stock solution is allowed to settle for ca. 1 h before extracting the solution for preparation of the test solutions from the centre of the liquid column.
- Differential loading: 0.34, 0.75, 1.65, 3.64, 80
- Controls: yes
- Evidence of undissolved material (e.g. precipitate, surface film, etc.):

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna Straus
- Source: Clone breeding of the German Federal Environment Agency, Department IV 2.4, Berlin
- Age of parental stock (mean and range, SD): not reported
- Feeding during test: no
- Food type (culturing): Desmodesmus subspicatus algae
- Amount (culturing): 0.1 mg C × daphnid-1 × day-1
- Frequency (culturing): fed on workdays

ACCLIMATION
- Acclimation period: breeding and cultivation 20 ± 2 °C with 16 h light : 8 h dark and placed into fresh Elendt M4 medium twice a week
- Acclimation conditions (same as test or not): same, except feeding
- Type and amount of food, feeding frequency: fed on workdays with Desmodesmus subspicatus algae corresponding to 0.1 mg C × daphnid-1 × day-1.
- Health during acclimation (any mortality observed): not reported

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

Swimming capability of the daphnids is determined after 24 h and 48 h exposure. Animals that do not swim within 15 s after gently moving the test vessel are considered to be immobile.

Test temperature:

18 – 22 °C; constant within ± 1 °C

pH:

Measurement of pH: At the start and at the end of the test.

Dissolved oxygen:

Measurement of O2-concentration: At the start and at the end of the test

Nominal and measured concentrations:

Nominal: 0, 0.34, 0.75, 1.65, 3.64, 80 mg/L
Measured: 0, 0.25, 0.54, 1.17, 2.81, 55.12 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 mL beakers
- Type (delete if not applicable): open / closed
- Material, size, headspace, fill volume: 40 mL
- Aeration:
- Type of flow-through (e.g. peristaltic or proportional diluter):
- Renewal rate of test solution (frequency/flow rate):
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates):
- No. of vessels per vehicle control (replicates):
- Biomass loading rate:

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt M4 medium according to OECD 202
- Total organic carbon:
- Particulate matter:
- Metals:
- Pesticides:
- Chlorine:
- Alkalinity:
- Ca/mg ratio:
- Conductivity:
- Salinity:
- Culture medium different from test medium:
- Intervals of water quality measurement:

OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod: 16 h light / 8 h dark
- Light intensity:

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mobility, Mortality

VEHICLE CONTROL PERFORMED: yes/no

RANGE-FINDING STUDY
- Test concentrations: 10, 100 and 500 mg/L test item loading rates
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

yes

Remarks:

Reference item potassium dichromate; recent quality testing was performed in February 2018 with EC50 (24h) = 1.80 mg/L (CL 95 %: 1.64 – 2.02 mg/L), which is in the declared range of 0.6 – 2.1 mg/L (24 h) according to OECD 202.

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

1.56 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

0.56 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.54 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

1.17 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Validity criteria fulfilled:

yes

Conclusions:

The test item showed toxic effects on Daphnia magna in a 48-h immobilization test according to OECD test guideline 202. The EC50 was calculated to be 1.56 mg/L based on geometric mean measured concentrations. The NOEC was determined to 0.54 mg/L and the LOEC was set to 1.17 mg/L.

Executive summary:

The 48–hr-acute toxicity of the test item to Daphnia magna Straus was studied under semi-static conditions according to OECD 202 (OECD 2003). Daphnids were exposed for 48 h to a control containing no test substance, and nominal test item loading rates of 0.34, 0.75, 1.65, 3.64 and 80 mg/L and measured concentrations of 0.25, 0.54, 1.17, 2.81 and 55.12 mg/L (geometric mean).

Mortality/immobilization and sublethal effects were observed daily. 

As the measured test item concentrations are not within ± 20 % of the nominal concentrations, according to OECD 201 (2004) and OECD 23 (2000), all results are given in relation to the analytically measured test item concentrations.

The 48 – hr EC₅₀ was 1.56 mg/L. 

The 48 – hr NOEC based on immobilization was 0.54 mg/L.

This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates. 

Results Synopsis

Test Organism Age (e.g. 1^st instar): < 24 h

Test Type: Static Renewal

  

- 48 hr EC50 (measured): 1.56 mg/L (95%-CL: 1.18 - 2.26);

- 48 hr EC20 (measured): 0.80 mg/L (95%-CL: 0.51 - 1.07);

- 48 hr EC10 (measured): 0.56 mg/L (95%-CL: 0.30 - 0.79);

- 48 hr LOEC: 1.17 mg/L;

- 48 hr NOEC: 0.54 mg/L.

Endpoint(s) effected: Immobility/Mortality

Description of key information

The 48-h semi static acute toxicity test with dibutyl peroxydicarbonate in Daphnia magna was conducted according to OECD test guideline 202. The EC50 (mobility) was calculated to be 1.56 mg/L with 95% CL of 1.18–2.26 mg/L based on geometric mean measured concentrations. The NOEC was determined to 0.54 mg/L and the LOEC was set to 1.17 mg/L.

As the test substance has peroxide content of 50.6 %, the EC50 for the peroxide itself is 0.79 mg/L. The EC10 was re-calculated to 0.28 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.79 mg/L