Diisobutyl phthalate

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Data from reliable source but only limited documentation given

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Diisobutyl phthalate

EC Number:

201-553-2

EC Name:

Diisobutyl phthalate

Cas Number:

84-69-5

Molecular formula:

C16H22O4

IUPAC Name:

diisobutyl phthalate

Details on test material:

no data

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

not specified

Details on test solutions:

- Preparation of the test solution
To prepare a test solution of each concentration, directly dissolve the required amount of the test substance in the medium, etc., or prepare a stock solution of the test substance at an appropriate concentration and dilute it with the medium, etc. Prepare the stock solution without using any vehicle, but if it is difficult to dissolve the test substance in water or the medium, etc., perform mechanical dispersion by means of ultrasonic wave, etc., or use a low-toxicity vehicle (which hereinafter refers to a solvent or dispersant) such as an organic solvent. However, as a rule, do not use any surfactant. Set the test concentrations so that they do not exceed the solubility (hereinafter referred to as "solubility limit") of the test substance to the medium, etc. under the test conditions.
When using a vehicle, additionally establish a vehicle control containing the vehicle at the same concentration as that used for preparing the test concentrations. In principle, the concentration of the vehicle must not exceed 100 mg/L and must be constant among all the test concentrations. Note that the obtained test results may be attributed to the test substance itself or its interactive effect with the vehicle.

Test organisms

Test organisms (species):

Oryzias latipes

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test conditions

Details on test conditions:

- Test vessel
The test vessel or other instrument that contacts the test solution must be made of glass or other chemically inert materials. Use a test vessel of an appropriate size in regard to the recommended volume. Cap the vessel loosely to prevent evaporation and dust contamination.
If the test substance is volatile, perform the test in a sealed system. Use a sufficiently large vessel to prevent shortage of dissolved oxygen.

- Material water
Use water suitable for culturing and testing the fish. It can be natural water (surface water or groundwater), dechlorinated tap water or artificially prepared water (see the note). The recommended total hardness is 10 - 250 mg/L in terms of calcium carbonate concentration, and the recommended pH is 6.0 - 8.5. Prepare the artificially prepared water using reagents of analytical grade and deionized or distilled water having an electric conductivity of 10 μS/cm or lower.


- Acclimatization
All test fish must be acquired at least 12 days before the test and acclimatized. After monitoring the fish for 48 hr, acclimatize them in water used for the test under the following conditions for at least 7 days before beginning the exposure. If possible, avoid using medicated bath after the monitoring period.
Illumination: 12 - 16 hr light per day
Temperature: Appropriate temperature for the species tested (see Appendix Table 1 under VI.)
Oxygen concentration: At least 80% of the saturated oxygen concentration
Feeding: Daily or three times per week until 24 hr before beginning the exposure.
Record the mortality during the acclimatization period and apply the following conditions to the test fish.


- Test solution
To prepare a test solution of each concentration, directly dissolve the required amount of the test substance in the material water, or prepare a stock solution of the test substance at an appropriate concentration and dilute it with the material water. Follow the descriptions in "Preparation of the test solution" under "III. General rules."
Perform the test without adjusting the pH. If the pH of the material water is greatly changed by the addition of the test substance, it is recommended to perform an additional test after adjusting the pH to that observed prior to the addition of the test substance. Perform the pH adjustment through a method causing no change in the concentration, chemical reaction or precipitation of the test substance. Preferably, use HCl or NaOH for the pH adjustment.



- Test method
The test should be performed under a flow-through or semi-static condition. If the test substance concentration is unstable, a flow-through test is recommended.

- Exposure period
Perform the exposure period for 96 hr.

- Volume and number of test fish

Volume: A maximum density of 1.0 g fish weight/L is recommended for a semi-static test. The volume can be larger in a flow-through test.
Number of test fish: Use at least 7 fish for each of the test concentrations and the control.
6-4. Test concentrations
Adopt a concentration range comprising at least 5 concentrations that are setup in a geometric progression, preferably at a geometric ratio of within 2.2. The highest test concentration preferably gives fatal effects on all individuals tested, but concentrations of 100 mg/L or higher do not need to be tested. Preferably, no effect is observed at the lowest concentration.
Perform a control, and additionally an auxiliary control if using any auxiliary.


- Test substance concentration measurement
At the beginning and end of the exposure, measure the test substance concentrations at least in the lowest and highest test concentration groups. If it has been predicted that the test substance concentration decreases from the initial concentration by 20% or more during the exposure period, it is recommended to take measurements for all test concentration groups at the beginning and end of the exposure. Furthermore, for volatile or adsorptive substances or those that are likely to be greatly decreased during the exposure period, additional measurements are recommended at 24 hr intervals during the exposure period.
In a semi-static test, perform at least two sets of measurements, provided that the measurements taken immediately after the water renewal and immediately before the next renewal are counted as one set.


- Test condition measurement
Measure the pH, dissolved oxygen concentration and water temperature at least once daily.

Reference substance (positive control):

not specified

Results and discussion

Effect concentrations

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

3 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)