3,5-dimethyl-1,2-dioxolane-3,5-diol

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: See Remarks

Remarks:

GLP study according to protocol. No CoA was included in the report therefore not enough detail on composition were available; a statement of the composition is attached to the robust summary. No detailed description of the results of the chemical analyses and system stability.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples from the control and 100 mg/L test solutions were taken immediately after the start of the test, after 24 hours, 48 hours (old solution and fresh solution) and after 96 hours of testing. The sample was 1:1 with deionized water and then immediately injected into the HPLC system. The amount of test substance present in the test concentrations was quantified by HPLC.

Vehicle:

no

Details on test solutions:

Two stock solution were prepared one just before the start of the test and one just before the renewal of the test medium at 48 hours. Both stock solutions were prepared by weighing an accurate measured amount of 0.9097 g for the first and 0.9089 g for the second stock solution into a 3 L test
medium and left to stir between 60 and 90 minutes. Initially droplets were observed and the test substance did not mix readily with the test medium but after 1 hour of stirring a clear solution was observed. The pH of both stock solutions was checked and adjusted to 0.2 units from the control using
a NaOH solution. The final concentration based an assumed active ingredient content of 2,4-pentanedione, peroxide content of 33% in the test substance is: 100.07 mg/L for the first and 99.98 mg/L for the second stock solution.
The stock solutions were used in the test without further dilution.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

The test was performed with juvenile Danio rerio (zebra fish), which were bred in-house and were accepted according to the quality control criteria of the guidelines. The fish in stock were fed one to three times per day with commercially available dry, deep-frozen food, or nauplii. The feeding was stopped 24 hours before the test was started, and the animals were not fed during the test. From five test fish the length was measured at the beginning of the test and showed the length of animals to be =<3 cm. The biomass loading was verified at the beginning and was measured 0.10 g/L for the definitive test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

11.5°dH

Test temperature:

23.1-24.1 °C

pH:

7.7-8.6

Dissolved oxygen:

8.1-8.6 mg O2/L

Nominal and measured concentrations:

Nominal active ingredient concentration: 100 mg/L
Time weighted average measured active ingredient concentration: 67.6 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 5-L aquaria containing 3 L of test solution were used. They were covered with glass plates during the test.
- Type (delete if not applicable): open
- Aeration: yes, with water saturated air purified by an active coal filter and a cotton filter.
- Renewal rate of test solution (frequency/flow rate): once after 48h
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.41 g/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Duthc Standards Water (DSW)
pH 8.2 and a conductivity between 550 and 650 µS/cm, containing per liter of de-ionized water: 100 mg of NaHCO3 , 20 mg of KHCO3, 200 mg of CaCI2·2H20 and 180 mg of MgSO4·7H2O. The test medium was aerated before being used in the test. The air was watersaturated and purified by an active coal and cotton filter.
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: Yes, the stock solution was adjusted to 0.2 units from the control using a NaOH solution
- Photoperiod: 16h
- Light intensity: ambient light provided by fluorescent tubes

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): mortality

Reference substance (positive control):

not specified

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 67.6 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Remarks on result:

other: Recalculated by the reviewer. LC50 reported as mean measured active ingredient concentration.

Details on results:

No lethality was observed of Danio rerio during the 96 hours semi-static exposure to a nominal concentration of 100 mg/L of 2,4-pentanedione, peroxide assuming 33% active ingredient content. Based on these test results the LC50 0-96h of active ingredient is >100 mg/L nominal. No other sub-lethal effects were observed during the test.

Remark from the reviewer: According to the sponsor the batch used in this study had an active ingredient content (2,4-pentanedione, peroxide) of 29.9%. The concentrations mentioned in the report are based on 33% acitve ingredient and have therefore been recalculated to 29.9%. The mean measured concentration is used for calculation of the endpoints. This has been changed to time weighted average concentration as several measurements were done during the test.

Reported statistics and error estimates:

If possible, the LC50 was calculated with the computer program version 5.0 using the trimmed Spearman-Karber method. The concentrations causing zero and 100% immobility were, if possible, derived directly from the test observations.

Validity criteria fulfilled:

yes

Conclusions:

This study is reliable with the above mentioned restrictions. It is performed according to OECD guideline 203 under GLP and all validity criteria were fulfilled.
The test substance was not stable during the test and therefore time weighted average concentrations were used. The calculated endpoints are adequate for C&L and risk assessment purposes.

Executive summary:

The acute toxicity of Acetylacetone peroxide (CAS# 37187-22-7) to the fresh water fish Dania rerio (zebra fish) was tested under semi-static conditions for 96 hours in accordance with OECD and EEC guidelines for testing of chemicals. The test was performed in compliance with Good Laboratory Practice (GLP).

Acetylacetone peroxide is miscible in water. A preliminary test on Danio rerio showed that Acetylacetone peroxide had no toxic effects at 100 mg/L Acetylacetone peroxide and therefore the definitive test was performed as a limit test at 100 mg/L.

No lethality was observed of Danio rerio during the 96 hours semi-static exposure to a nominal concentration of 100 mg/L of acetylacetone peroxide assuming 33% active ingredient content. Based on these test results the LC50 0-96h of Acetylacetone peroxide is >100 mg/L Nominal. No other sub-lethal effects were observed during the test.

Two peaks were considered to represent the test substance in the chromatogram a decrease is observed in the sum of both peaks during the first 48 hours of testing of 40.5% and 43.5% of the nominal concentration during the second 48 hours of testing. Acetylacetone peroxide is not stable under test conditions. Since acetylacetone peroxide is not stable under test conditions, the effect concentrations should be based on the measured concentrations. Based on measured concentrations, the LC50 96 h for fish of acetylacetone peroxide is >77.48 mg/L.

Remark from the reviewer: The results given in this summary are as given in the report, so have not been converted to time weighted average concentrations.

Description of key information

The 96h-LC50 for fish is greater than 67.6 mg a.i./L (measured TWA), The 96h-NOEC is greater than or equal to 67.6 mg a.i./L..