Tetrabutylphosphonium bromide

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:

From 16 November 2015 to 22 December 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

(1992)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Version / remarks:

(2008)

Deviations:

no

Qualifier:

according to guideline

Guideline:

ISO 7346-1 (Determination of the Acute Lethal Toxicity of Substances to a Freshwater Fish [Brachydanio rerio Hamilton-Buchanan (Teleostei, Cyprinidae)] - Part 1: Static Method)

Version / remarks:

(1996)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations sampled: all test concentrations, at t=0 and t=96h (but not all were measured)
- Sample storage conditions before analysis: in a freezer

Vehicle:

no

Details on test solutions:

The test item was completely miscible in test medium at the concentrations tested. Preparation of test solutions started with the highest test concentration of 100 mg/L. No special treatment other than careful mixing was necessary to completely dissolve the test item in medium. Lower test concentrations were prepared by subsequent dilutions in test medium. The final test solutions were all clear and colourless.

Test organisms (species):

Cyprinus carpio

Details on test organisms:

TEST ORGANISM
- Common name: Carp
- Source: Zodiac, proefacc, "De Haar Vissen", Wageningen University and Research Centre, The Netherlands
- Characteristics: F1 from a single parent-pair bred in UV-treated water
- Mean length at study initiation:
-- Range-finding test: 2.1 ± 0.1 cm
-- Final test: 2.1 ± 0.1 cm
- Mean weight at study initiation:
-- Range-finding test: 0.14 ± 0.05 g
-- Final test: 0.28 ± 0.06 g

ACCLIMATION
Acclimation period: At least 12 days after delivery

FEEDING
Daily with pelleted fish food (Essence (300-500 um), Coppens International bv, Helmond, The Netherlands).

FEEDING DURING TEST
No feeding for 24 hours prior to the test and during the total test period.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

180 mg CaCO3 per litre

Test temperature:

20.8 - 21.4 °C

pH:

7.3 - 7.9

Dissolved oxygen:

6.7 - 9.4 mg/L

Nominal and measured concentrations:

- 10, 18, 32, 56 and 100 mg/L (nominal)
- Analysis of the samples taken from 100 mg/L at the start and the end of the final test showed that measured concentrations were stable and in agreement with nominal (96-105% relative to nominal)

Details on test conditions:

TEST SYSTEM
- Test vessels: 6.5 litres, all-glass, containing 5 litres of test solution
- Aeration: no
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Loading: 0.39 g fish/L

TEST MEDIUM
Adjusted ISO medium with a hardness of 180 mg CaCO3 per litre and a pH of 7.7 ± 0.3, formulated using RO-water (tap water purified by reverse osmosis; GEON Waterbehandeling, The Netherlands) with the following composition:
CaCl2.2H2O: 211.5 mg/L
MgSO4.7H2O: 88.8 mg/L
NaHCO3: 46.7 mg/L
KCL: 4.2 mg/L

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours photoperiod daily

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
Range finding study:
- Test concentrations: 0.1, 1.0, 10 and 100 mg/L (3 fish/concentration)
- Results used to determine the conditions for the definitive study:
No mortality was observed. The expected LC50 was above 100 mg/L.

Reference substance (positive control):

yes

Remarks:

(yearly sensitivity check using pentachlorophenol)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Analytically confirmed nominal test concentration

Details on results:

No mortality was observed in any of the test groups. Clinical effects were only observed at 100 mg/L at the end of the study and were limited to exophtalmus and a slightly darker colour.

Results with reference substance (positive control):

In the latest sensitivity check, performed in the period 4 - 8 January 2016, a 96h-LC50 of 0.24 mg/L was determined for carp exposed to pentachlorophenol. This is within the range observed during the past years.

Sublethal observations / clinical signs:

Range-finding test:

Carp were affected from 24 hours onwards showing effects on swimming behaviour. These limited effects were mainly related to swimming at the top of the tank, snapping at the surface and head dominant swimming. Based on these results samples taken from nominal 10 mg/L were analysed. The measured concentration was stable and in agreement with nominal (105-107% relative to nominal).

 

Table 1: Mortality observed in the definitive test (none)

Concentration (mg/L, nominal)	Initial nb of fish	Mortality after 96 h	%Mortality
Control	7	0	0
10	7	0	0
18	7	0	0
32	7	0	0
56	7	0	0
100	7	0	0

Table 2: Nominal and measured concentrations

Concentration (mg/L, nominal)	Concentration (mg/L, measured, 0h)	Concentration (mg/L, measured, 96h)
Control	0.01	0.001
100	96	105

Validity criteria fulfilled:

yes

Conclusions:

In a study performed in accordance with OECD 203 (1992) and according to GLP principles, an 96h-LC50 of >100 mg/L was determined, based on analytically confirmed nominal concentrations.

Executive summary:

In a study performed in accordance with OECD 203 (1992) and according to GLP principles, the acute toxicity of the substance to carp was investigated. A final test was performed based on the results of a preceding range-finding test. Seven carp per test group were exposed to an untreated control and to nominal test item concentrations of 10, 18, 32, 56 and 100 mg/L. The total test period was 96 hours and samples for analytical confirmation of actual exposure concentrations were taken at the start and the end of the test period. No mortality was observed in any of the test groups during the 96-hour test period. Analysis of the samples taken from 100 mg/L at the start and the end of the final test showed that measured concentrations were stable and in agreement with nominal (96-105% relative to nominal). The study met the acceptability criteria. Based on the results of the test, an 96h-LC50 of >100 mg/L was determined, based on analytically confirmed nominal concentrations.

Description of key information

In a study in accordance with OECD 203 (1992) and according to GLP principles, the acute toxicity of the substance to carp was investigated. A final test was performed based on the results of a preceding range-finding test. Seven carp per test group were exposed to an untreated control and to nominal test item concentrations of 10, 18, 32, 56 and 100 mg/L. The total test period was 96 hours and samples for analytical confirmation of actual exposure concentrations were taken at the start and the end of the test period. No mortality was observed in any of the test groups during the 96-hour test period. Analysis of the samples taken from 100 mg/L at the start and the end of the final test showed that measured concentrations were stable and in agreement with nominal (96-105% relative to nominal). The study met the acceptability criteria. Based on the results of the test, an 96h-LC50 of >100 mg/L was determined, based on analytically confirmed nominal concentrations.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

100 mg/L