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Short-term toxicity to fish

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Reference
Endpoint:
short-term toxicity to fish
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 2003-12-22 to 2004-02-25
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study performed according to OECD 203 and under GLP but no analytical measurment were performed and the report is not well documented (preliminary study of a Bioaccumulation test performed by NITE 2004).
Qualifier:
according to
Guideline:
OECD Guideline 203 (Fish, Acute Toxicity Test)
Version / remarks:
1992 version
Deviations:
yes
Remarks:
major: the concentation of the test substance in the test solution was not measured and the result LC50 was calculated based on the nominal concentration.
GLP compliance:
yes
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
Solubility: Water 0.14 mg/L (measurement value using the Flask method).
Analytical monitoring:
no
Details on sampling:
- Concentrations: 0, 1, 2, 4, and 8 mg/L
- Sampling method: The sampling method is described in Fig.2
- Sample storage conditions before analysis: not applicable
Vehicle:
yes
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test solution was prepared by first obtaining 460 µL of the test substance to mix with 8 g of HCO-40 and then bringing the final volume to 20 mL with 2-methoxyethyl alcohol. Then, 0.25, 0.5, 1, 2 mL of the solution was individually added to 5 L of the dilution water.
- Differential loading:
+ test substance concentration: 1, 2, 4, 8 mg/L
+ HCO-40 concentration: 20, 40, 80, 160 mg/L
+ 2-methoxy alcohol concentration: 240 ppm (v/v)
- Controls: The test solution was prepared by first obtaining 8 g of HCO-40 to add in 2-methoxy alcohol to bring the final volume to 20 mL. Then, 2 mL of the solution was added to the 5 L of the dilution water.
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)): < 0.04% of 2-methoxyethyl alcohol.
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no data
Test organisms (species):
Oryzias latipes
Details on test organisms:
TEST ORGANISM
- Common name: Medaka
- Source: Amijima Fisheries (Kanagawa Ken, Yokohama Shi, Minato Kita Ku Amijima Nishi 5-18-1.).
- Lot number: 03-H-0714
- Acquisition date: July 14, 2003
- Age at study initiation (mean and range, SD): no data
- Length at study initiation (length definition, mean, range and SD): 2 +/- 1 cm
- Weight at study initiation (mean and range, SD): ca. 0.2 g
- Method of breeding: no data
- Feeding during test: yes
- Food type: no data
- Amount: no data
- Frequency: no data

ACCLIMATION
- Acclimation period: at least 2 weeks
- Acclimation conditions (same as test or not): same as test. Yes
- Type and amount of food: TetraMin (Tetra Werke), equivalent to 2% of fish bodyweight
- Feeding frequency: daily but no feed for 24h prior to the test
- Health during acclimation (any mortality observed): At the time of commencing purification, visual obsertankion is made, abnormal specimens are removed, and the fish are raised in flowing water. During purification, there is no addition of a medicated solution. No chemical treatment during the habituation period was conducted. Death rate less than 5% .
Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
96 h
Post exposure observation period:
no data
Hardness:
no data
Test temperature:
24 +/- 1°C
pH:
no data
Dissolved oxygen:
At least 60% of saturated-dissolved oxygen concentration
Salinity:
not applicable
Nominal and measured concentrations:
Nominal concentrations: 0, 1, 2, 4, and 8 mg/L
Details on test conditions:
TEST SYSTEM

- Material, size, headspace, fill volume: Sealed conditions, 5 Litres
- Aeration: Bubbling oxygen
- Renewal rate of test solution (frequency/flow rate): water replacement every 24h
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates):1
- No. of vessels per control (replicates):1
- No. of vessels per vehicle control (replicates):0
- Biomass loading rate: no data

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: no data


OTHER TEST CONDITIONS
- Adjustment of pH: no data
- Photoperiod: no data
- Light intensity: no data

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : mortality
Reference substance (positive control):
no
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
ca. 4.5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality
Details on results:
no data available on the individual effect per test concentration
Results with reference substance (positive control):
not applicable
Reported statistics and error estimates:
no data
Validity criteria fulfilled:
yes
Conclusions:
The results demonstrated a LC50(96h) = 4.5 mg/L of 2,5 dimethyl-2,5-di (tert-butyl peroxy) hexane on the fish Medaka (Oryzias latipes, Medaka). This value is greater than the limit of solubiltiy of the test substance.
Executive summary:

Acute toxicity of 2,5 dimethyl-2,5-di (tert-butyl peroxin) hexane named K-1385 was tested on the fish type medaka, Oryzias latipes, following OECD guideline 203 and under GLP. However, no analytical measurments were performed and the report is poorly documented because the test was a preliminary study for a bioaccumulation test.

Seven fish per concentration were exposed to 0, 1, 4, and 8 mg/L nominal concentrations under semi-static conditions for 96 h. The test solutions were prepared by first obtaining 460 µL of the test substance to mix with 8 g of HCO-40 and then bringing the final volume to 20 mL with 2-methoxyethyl alcohol. Then, 0.25, 0.5, 1, 2 mL of the solution was individually added to 5 L of the dilution water. The test conditions were 24 +/-°C and at least 60% of saturated-dissolved oxygen concentration. The 96hr-LC50 determined at 4.5 mg/L was calculated by Dodoroff method (Probit analysis). While no concentration related data are available, it can be concluded that the observed toxicity is significantly higher than the water solubility of the test substance (measured as part of the same NITE study (2004) in a shake flask test as 0.014 mg/L.

Description of key information

Based exclusively on one study in medaka, acute toxicity of 2,5 dimethyl-2,5-di (tert-butyl peroxin) hexane named K-1385 was tested on the fish type medaka, Oryzias latipes, following OECD guideline 203 and under GLP. The 96hr-LC50 determined at 4.5 mg/L was calculated by Dodoroff method (Probit analysis). This value greatly exceeds the limit of solubility (determined in a shake flask method as 0.014 mg/L).

Key value for chemical safety assessment

Additional information

Based on one study in medaka, acute toxicity of 2,5 dimethyl-2,5-di (tert-butyl peroxy) hexane named K-1385 was tested on the fish type medaka, Oryzias latipes, following OECD guideline 203 and under GLP. Seven fish per concentration were exposed to 0, 1, 4, and 8 mg/L nominal concentrations under semi-static conditions for 96 h. The test solutions were prepared by first obtaining 460 µL of the test substance to mix with 8 g of HCO-40 and then bringing the final volume to 20 mL with 2-methoxyethyl alcohol. Then, 0.25, 0.5, 1, 2 mL of the solution was individually added to 5 L of the dilution water. The test conditions were 24 +/-°C and at least 60% of saturated-dissolved oxygen concentration. The 96hr-LC50 determined at 4.5 mg/L was calculated by Dodoroff method (Probit analysis). This value greatly exceeds the limit of solubility of the test substance.