Isobutylamine

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

fish embryo acute toxicity (FET)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

data published in 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: The primary objective of this study is to assess the scientific supportability of the fish embryo test to be a surrogate for the OECD 203 acute fish toxicity test (or other guideline equivalent acute fish assays).
- Short description of test conditions: The test substance should be tested in at least 5 concentrations prepared as dilutionswith standard dilutionwater. The use of solvents ordispersants (solubilizing agents) should be avoided, but may be required in some
cases in order to produce a suitably concentrated stock solution. In addition to the examples of suitable solvents given in OECD (2000a), dimethylsulfoxide (DMSO) might be useful. The final concentration of the solubilizing agent should not exceed 100 μl/L when required for preparing stock solutions and preferably be the same in all test vessels. Dilution water in the absence of the chemical is used as a negative
control. As a standard positive control, 3.7 mg/L 3,4-dichloroaniline
should induce embryonicmortality N10% (DIN 38415-T6; ISO 15088); in
the authors' laboratories, this concentration typically results in 20–80%
mortality. Each chemical is tested in at least two independent replicates
(with ten eggs/embryos per test concentration and controls).
2.1.6. Distribution of eggs over 24-well plates
Following suspension in the test concentrations or any of the
controls, 10 fertilized eggs are selected using a stereo microscope and
transferred to 24-well plates filled with 2 mL freshly prepared test
solutions and controls per well (Fig. 2). For the distribution of the 5
test concentrations and respective controls over the 24-well plates,
see Fig. 3. The 24-well plates are then covered with self-adhesive foil
and incubated at 26.0 °C±1.0 °C for 24, 48, 96 and 108 h.
2.1.7. Toxicological endpoints for the determination of chemical toxicity
The apical endpoints for the assessment of acute chemical toxicity
are identical to those used for the determination of whole effluent
toxicity (DIN 38415-T6; ISO 15088): coagulation of the embryo, nondetachment
of the tail, non-formation of somites and non-detection of
the heartbeat. However, in contrast to whole effluent testing, these are
recorded after 24, 48 and 96 h (Table 1). Since zebrafish embryos
usually hatch after 72 h, non-hatching may be listed as a further lethal
endpoint after 108 h. In addition to these core endpoints, which are
regarded lethal, a number of endpoints may be recorded as evidence of
sublethal toxicity or teratogenicity (“any other observation”; Table 1).






- Parameters analysed / observed:

GLP compliance:

no

Remarks:

the study was conducted for research purposes and therefore not cnducted under GLP.

Analytical monitoring:

not specified

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Test type:

static

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

92.6 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Validity criteria fulfilled:

yes

Conclusions:

In reference to Brust (2001) work on "toxicity of aliphatic amines on the embryos of zebrafish Danioarerio - experimental studies and QSAR, the publication provide an 48h- LC50 value of 92.6 mg/L.

Executive summary:

In a publication relating the fact that the fish embryo tests are neither better nor worse than acute fish toxicity tests and provide strong scientific support for the FET as a surrogate for the acute fish toxicity test, results in reference to Brust 2001 mention that a 48h exposure of isobutylamine to Danio rerio embryo lead to a LC50 value of 92.6 mg/L.

Description of key information

In a publication showing that the fish embryo tests are neither better nor worse than acute fish toxicity tests and provide strong scientific support for the FET as a surrogate for the acute fish toxicity test, results in reference to Brust (2001) study mention that a 48h exposure of isobutylamine to Danio rerio embryo lead to a LC50 value of 92.6 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

92.6 mg/L