2,5-di-tert-pentylhydroquinone

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:

23 July 1983 to 27 July 1983

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP study similar to OECD guideline 203. No analytical determination of the test substance.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

: no analytical determination of the test substance

GLP compliance:

yes

Analytical monitoring:

no

Details on sampling:

not applicable

Vehicle:

yes

Details on test solutions:

- vehicle: nanograde acetone
- appropriate aliquots of a working solution were transferred directly to test chambers
- working solution was prepared by dissolving 0.75 g of test compound in 500 mL of acetone, resulting in a working concentration of 1.5 mg/mL
- maximum concentration of vehicle used (=solvent control): 0.06 mL/L
- dilution water: laboratory well water

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

- common name: bluegill sunfish
- source: Osage Catfisheries Incorportaed in Osage Beach, Missouri
- ABC Lot #: 2983
- fish were identified to species using the taxonomic keys developed by Eddy (1969)
- breeding conditions:
* photoperiod: 16 hour daylight
* at least 14 days prior to testing
* observations were reported daily
* fish were treated with prophylactic and therapeutic disease treatments
* food: standard commercial fish food (Rangen's)
* feeding frequency: daily until 48 hours prior to testing
- length at end of test (control): 19 ± 1.5 mm (mean ± S.D.)
- weight at end of test (control): 0.14 ± 0.03 g (mean ± S.D.)
- fish were held in test conditions (acclimation) during 48 hours prior to testing

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

255 mg/L CaC03 (well water, no data during test)

Test temperature:

water bath: 22 ± 1 °C

pH:

8.2 (well water)
at 0 hours: control 8.0, 0.010 mg/L 8.1, 0.10 mg/L 8.1
after 96 hours: control 8.0, 0.010 mg/L 7.9, 0.10 mg/L no data due to 100 % mortality

Dissolved oxygen:

9.3 mg/L (well water)
at 0 hours control D0=8.6 mg/L, 0.010 mg/L DO=8.4 mg/L, 0.10 mg/L DO=8.6 mg/L
after 96 hours: control DO=5.1 mg/L, 0.010 mg/L DO=4.8 mg/L, 0.10 mg/L no data due to 100 % mortality

Salinity:

not applicable

Nominal and measured concentrations:

nominal concentrations: control, solvent control, 0.010, 0.018, 0.032, 0.056, 0.10 mg/L
measured concentrations: no analytics performed

Details on test conditions:

- fish were not fed during testing
- test vessel: 5-gallon glass vessels
- test volume: 15 L
- range-finding test:
* test duration: 24 and 96 hours
* test concentrations: 0.001, 0.01, 0.1, 1, 10 mg/L
* 5 fish per vessel
* results: no mortality in 0.001 and 0.01 mg/L and 100 % mortality in 0.1, 1 and 10 mg/L
- 10 fish per test vessel (randomly added to test vessels within 20 minutes after addition of test compound)
- N° replicate vessels per concentration: 1

Reference substance (positive control):

yes

Remarks:

Antimycin A

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

0.013 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Santovar A

Basis for effect:

mortality (fish)

Remarks on result:

other: 95 % CL: 0.010-0.018 mg/L (binomial method)

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

0.01 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Santovar A

Basis for effect:

mortality (fish)

Details on results:

- mortality: 100 % mortality in 0.032, 0.056, 0.010 mg/L after 24 hours; 80 % mortality in 0.018 mg/L after 24 h increasing to 100 % after 72 hours; no mortality in control, solvent control and in 0.010 mg/L

Results with reference substance (positive control):

- mortality: 100 % in 0.00014 and 0.00024 mg/L after 24 hours; 10 % mortality in 0.000075 mg/L after 24 hours increasing to 60 % mortality after 72 h; no mortality in control, solvent control, and 0.000014 and 0.000042 mg/L.
96h-LC50: 0.00007 mg/L (95% CI: 0.00001-0.00014 mg/L)

Reported statistics and error estimates:

LC50 values and 95 % confidence levels were obtained from bionomial and probit data analyses with a computerized program developed by Stephan et al. (1978).

Validity criteria fulfilled:

not applicable

Conclusions:

Reliable study (Klimisch 2) reporting a 96-h LC50 value of 0.013 mg/L Santovar A for the freshwater fish Lepomis macrochirus.

Executive summary:

The acute toxicity of Santovar® A to bluegill sunfish (Lepomis macrochirus) was assessed using the methods outlined by the Committee on Methods for Toxicity Tests with Aquatic Organisms. Water quality parameters of temperature, dissolved oxygen and pH were measured throughout the test and were within acceptable limits.

 

As a quality check, the bluegill sunfish were challenged with a reference compound, Antimycin A. The estimated 96 hour LC50 and 95% confidence limits (C.I.) were within the 95% confidence limits reported in the literature, indicating that the fish were in good condition.

 

The results of the four day static fish toxicity study using Santovar® A are summarized below. The 24 and 48 hour LC50 values were also determined.

 

Compound                 96-hour (95% C.I.)

Santovar® A              0.013 mg/l

                                   (0.019-0.018 mg/l)

Antimycin A               7.0 x 10^-5mg/l

                                   (4.2-14) x 10^-5mg/l

 

Also, the results indicated a 96-hour, no-observed effect concentration of 0.010 mg/l, which was based on the lack of mortality and/or abnormal effects.

Description of key information

The key value for the acute toxicity to fish was derived from a study performed according to a guideline equivalent or similar to OECD Guideline 203 for acute toxicity testing in fish. In this study, an LC50 value of 0.013 mg/L was derived for bluegill sunfish (L. macrochirus) after an exposure of 96 hours in a static test. The LC50 value was derived based on nominal concentrations as no analytical measurements were performed.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.013 mg/L

Additional information

Of the four relevant studies that were available, one was found unreliable. In this study (EG&G Bionomics, 1977, BN-76-261), 96-h LC50 values were derived for rainbow trout (LC50 = 0.04 mg/L) and bluegill sunfish (LC50 = 0.034 mg/L), but the study report was inadequate to allow proper assessment of the data. All other three studies were performed under GLP and according to a guideline similar to OECD guideline 203 (Fish, Acute toxicity testing). Nominal concentration-based LC50 values were found for bluegill sunfish (LC50 = 0.013 mg/L; ABC Laboratories, 1983, AB83X042), fathead minnow (LC50 = 0.12 mg/L; ABC Laboratories, 1980, AB-80-396), and rainbow trout (LC50 = 0.047 mg/L; ABC Laboratories, 1983, AB83X043). As all reliable studies were equally well-performed and –documented, the most sensitive result was assigned as key value.