Pentane-2,4-dione

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

Study period:

1980-04-23 to 1980-04-27

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study well documented meeting generally accepted principles

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

see Principles

Principles of method if other than guideline:

25 fishes per group; Lake Superior water; 5 concentrations (28.5-295 mg/l) and control with duplication were tested, analytical control by GLC in 24 h intervals up to 96 h; the tank volume was 6,3 l.

GLP compliance:

not specified

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
not applicable

Analytical monitoring:

yes

Details on sampling:

chemical analysis by Gas-Liquid chromatography (GLC)

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: undiluted injection
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no

Test organisms (species):

Pimephales promelas

Details on test organisms:

Fathead minnows used in the tests were cultured from brood stock provided by the U.S. EPA Environmental Research Laboratory-Duluth. Adults were held at 25 °C in flowing water at 16 hr light controlled-photoperiod and fed frozen adult brine shrimp (Artemia sp.). They were provided with asbestos pipe (cut in half longitudinally) as spawning substrate. Eggs were spawned and fertilized on the undersides of these substrates. The embryos were tended by the male parent until eye-up at which time the substrates with embryos attached were removed to another 25 °C bath where hatching occurred.
Fry of similar age were transferred to flow-through rearing tanks at 25 °C with a 16 hr light pho-toperiod. Fry were fed freshly hatched brine shrimp nauplii to excess three times daily until 24 hr before a test (twice on most week ends) and a dry flake ration during their first week. Fish that were approximately 30 days old were used in the toxicity tests.
Only groups of fish having healthy appearance and no history of unusual thermal exposure or abnormally high mortality rate were used for toxicant exposures. Fish were not fed during chemical exposures.
Mean length: 21.8 mm (+/- 2.386 mm)
Mean weight: 0.145 g (+/- 0.0486 g)
Loading rate: 0.575 g/l

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

not reported

Hardness:

hardness 46.2 mg/l CaCO3

Test temperature:

25.2 °C

pH:

pH 7.37

Dissolved oxygen:

6.3 mg/l dissolved oxygen

Nominal and measured concentrations:

0, 60.5, 101, 168, 280 and 467 mg/l (nominal);
0; 26.2 and 35.0; 56.0 and 57.2; 87.9 and 96; 145 and 152, 269 and 271 mg/l ( mean measured in duplicate replicates)

Details on test conditions:

Prior to initiating a test, prospective test fish were pooled if reared in more than one tank, and by inspection unusually large or small individuals were netted out with minimal disturbance to the remainder of the fish. At the start of a test, fish were removed from the “common pool” of fish with a beaker or net and distributed at random, among the exposure chambers.
During exposure to toxicants the fish were routinely observed for behavioral responses (effects) and deaths. Early tests were sometimes without effect observations. The concentration of the highest tested dose were at the limit of water solubility. Death was defined as the cessation of opercular movements and the inability to respond when prodded. Dead fish were removed and recorded at 3, 6, 12, 24, 48 72 and 96 hr from initial exposure.
At the termination of tests, control fish were weighted (wet) to the nearest mg after blotting ex-cess water from them with a paper towel and measured (standard length) to the nearest mm.

Flow-through exposures were conducted with cycling proportional diluters with duplicate exposures for every tested concentration. Toxicants were proportionally diluted with Lake Superior water from stock solutions before delivery to fish exposure chambers. Duplicated exposures were performed. Test chemicals were prepared by undiluted injection of the test substance.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

104 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 98.3 - 110 mg/l (95% CL)

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

68.5 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

behaviour

Remarks on result:

other: 64.3 - 71.9 mg/l (95% CL)

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

57.2 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

145 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

The number of mortalities was noted every 24 h after beginning of the test, at which time they were also removed.
The estimated LC 50 with corresponding 95 % confidence interval (98,3 - 110 mg/l) was calculated using the corrected average of the analyzed tank concentrations.
Affected fish became hyperactive and then lost equilibrium prior to death.

Reported statistics and error estimates:

Estimation of the LC50 and EC50 was made using the trimmed Spearman-Karber” method. Calculations were made for 96 hr of exposure and also for intermediate exposure times using mean exposure concentrations of toxicants for the duration of the test. Calculations of means ands standard deviations were rounded to the same precision as the original determinations.

Conclusions:

Substance is not harmful to fish.

Executive summary:

2,4-Pentanedione (> 99% pure) was assessed in an 96 h flow through acute toxicity test on Pimephales promelas according to a guideline similar to OECD 203. Five concentrations (28.5-295 mg/l) and control with duplication were tested on groups of 25 fish which were 30 days old at the beginning of the test. The concentration of the test item was monitored daily by analytical gas liquid chromatography showing a recovery rate of 108% (mean). The test showed mortality in groups at or exceeding 87.9 mg/l and all fish were found dead at 96 h at concentrations of the test item of or exceeding 145 mg/l. The EC50 based on behavioral effects was 68.5 mg/l with a confidence interval of 64.3 to 71.9 mg/l whereas the LC50 was 104 mg/l (98.3 to 110 mg/l 95% confidence interval).

Description of key information

In the study of Brooke et al. (1984) 2,4-Pentanedione (> 99% pure) was assessed in an 96 h flow through acute toxicity test on Pimephales promelas according to a guideline similar to OECD 203. The test showed mortality in groups at or exceeding 87.9 mg/l and all fish were found dead at 96 h at concentrations of the test item of or exceeding 145 mg/l. The EC50 based on behavioral effects was 68.5 mg/l with a confidence interval of 64.3 to 71.9 mg/l whereas the LC50 was 104 mg/l (98.3 to 110 mg/l 95% confidence interval).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

EC50

Effect concentration:

68 mg/L