Tetrabutyltin

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:

January 26 1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

no guideline followed

Principles of method if other than guideline:

Exposure of fish was performed either in a static, renewal, or flow-through system. Fish were exposed to 0, 20, 40, 60, 80 and 100 % of the stock solution for 96 hours.

GLP compliance:

not specified

Analytical monitoring:

yes

Vehicle:

not specified

Details on test solutions:

- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)): 98 µg/L liq-liq equil

Test organisms (species):

Pimephales promelas

Details on test organisms:

TEST ORGANISM
- Common name: fathead minnow
- Age at study initiation (mean and range, SD): 31 days
- Length at study initiation (length definition, mean, range and SD): mean 19.7 mm, SD 0.823 mm
- Weight at study initiation (mean and range, SD): mean 0.109 g, SD 0.0157 g

Test type:

not specified

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

44.3 mg/L CaCO3 (± 0.65)

Test temperature:

25.3 °C (± 0.21)

pH:

7.7 ± 0.02

Dissolved oxygen:

6.8 mg/L (± 0.29)

Nominal and measured concentrations:

Nomianl: 0, 20, 39, 59, 78 and 98 µg/L

Details on test conditions:

TEST SYSTEM
- Tank volume: 0.25 L
- No. of organisms per vessel: 10
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Lake Superior water
- Additions: 40.3 V/D
- Alkalinity: 44.1 mg/L CaCO3 (± 2.17)

OTHER TEST CONDITIONS
- Adjustment of pH: When the pH of the stock was outside the range of 7 to 8, the pH was adjusted to approximately that of the Lake Superior water (pH 7.7) with either NaOH or concentrated HCl.

Control had 0 µg/L of toxicant. Percent recovery was 92.3 (3.83). Loading was 0.1082 G/L/D. FIsh were exposed to 0, 20, 40, 60, 80 and 100 % of stock solution.

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

45.2 µg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Conf. Lim: 41.6-49.2 µg/L

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

45.2 µg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

other: based upon loss of equilibrium as manifested by the fish's inability to maintain an upright position when swimming.

Remarks on result:

other: Conf. Lim: 41.6-49.2 µg/L

Details on results:

- Behavioural abnormalities: Affected fish were hyperactive, had increased respiration and lost equilibrium prior to death.
- Mortality of control: 0

Reported statistics and error estimates:

Estimated LC50 and EC50 with 95 % confidence intervals were calculated using the corrected average of the analyzed tank concentrations and the Trimmed Spearman-Karber Method.

Confidence limits could not be calculated under the following conditions: lack of monotonically increasing deaths or effects with expsoure concentrations, no complete (100 %) effect concentration, no unaffected (0 %) concentration and no concentration with a partial (>0 and <100 %) effect.

Sublethal observations / clinical signs:

Table 1: Test Concentrations

Date	Control	A	B	C	D	E
Nominal	0	20.0	39.0	59.0	78.0	98.0
01/26/87	<2.0	19	30	41	65	130
01/27/87	<2.0	19	37	40	78	82
01/28/87	<2.0	19	38	44	59	99
01/29/87	<3.1	19	42	54	72
01/30/87	<2.3	25	31	35	73
Average	< 2.30	20	36	43	69	102
Cor. Ave.	< 2.49	21.2	38.6	46.4	75.2	111
Percent recovery: 92.3 % (± 3.83) N = 4

Table 2: Mortalities

Mortalities	Concentration (µg/L)
Hours	Control	20	39	59	78	98
Initial	10	10	10	10	10	10
24						8
48					10	10
72				2	10	10
96				8	10	10

Table 3: Observed effects

Effect	Concentration (µg/L)
Hours	Control	20	39	59	78	98
Initial	10	10	10	10	10	10
24						8
48					10	10
72				3	10	10
96				8	10	10

Validity criteria fulfilled:

yes

Conclusions:

Affected fish were hyperactive, had increased respiration and lost equilibrium prior to death. 96 hr LC50: 45.2 µg/L, 96 hr EC50: 45.2 µg/L.

Executive summary:

Fathead minnows were exposed to tetrabutyltin at nominal concentrations of 0 (control), 20, 39, 59, 78, and 98 µg/L. Fish were exposed to 0, 20, 40, 60, 80, and 100 % of the stock solution for 96 hours. Affected fish were hyperactive, had increased respiration and lost equilibrium prior to death. 96 hr LC50 was 45.2 µg/L and 96 hr EC50 was 45.2 µg/L.

Description of key information

Tetrabutyltin was determined to have a 96 hour LC50 value of 45.2 µg/L, along with an 96 hour EC50 value also of 45.2 µg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

45.2 µg/L

Additional information

Four studies are available to address this endpoint.

Short-term toxicity to fish.001: 96 hr LC50: 45.2 ug/L, 96 hr EC50: 45.2 ug/L

Short-term toxicity to fish.002: LC50: 9 µg/L

Short-term toxicity to fish.003: 96 hr LC50: 185 µg/L

Short-term toxicity to fish.004: 48 hr LC50: 5.21 mg/L

Short-term toxicity to fish.001 was selected as the key study on the basis that it was conducted for 96 hours and the methodology was well documented. The LC50 value obtained in the study was 45.2 µg/L, which was significantly lower than the other 96 hour study.