2,5-dimethyl-1H-pyrrole

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD Guideline Study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2,5-dimethyl-1H-pyrrole

EC Number:

210-913-8

EC Name:

2,5-dimethyl-1H-pyrrole

Cas Number:

625-84-3

Molecular formula:

C6H9N

IUPAC Name:

2,5-dimethyl-1H-pyrrole

Constituent 2

Reference substance name:

2,5-Dimethylpyrrole

IUPAC Name:

2,5-Dimethylpyrrole

Test material form:

other: yellowish liquid

Details on test material:

The batch of 2,5-Dimethylpyrrole tested was a yellowish liquid with a purity of 99.7%.

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

During the final test single samples for TOC-analyses were taken from all test concentrations
and the blank-control.
At t= 0 hand t= 96 h and at intermediate time intervals
in case all fish had died in a particular test group.
40 ml from the approximate centre of the test vessels.
Samples were stored in a freezer until analysis.
Additionally, single reserve samples of 40 ml were taken from all test solutions for possible
TOC-analysis. If not already used, these samples were stored in a freezer for a maximum of
three months after delivery of the draft report, pending on the decision of the sponsor for
additional analysis.

Test solutions

Details on test solutions:

Test concentrations of 10 and 100 mg/I were prepared and kept for 96 hours under test conditions in yellow light.
Duplicate samples of 40 ml were taken for TOC-analyses at the start, after 24 and 96
hours of exposure.

Test organisms

Test organisms (species):

Cyprinus carpio

Details on test organisms:

Carp (Cyprinus carpio, Teleostei, Cyprinidae)
Linnaeus, 1758
Zodiac, proefacc, "De Haar Vissen", Wageningen
University and Research Centre, the Netherlands.
Range-finding test: 2.7 ± 0.2 cm
Final test: 2.6 ± 0.2 cm
Range-finding test: 0.62 ± 0.21 g
Final test: 0.50 ± 0.11 g
F1 from a single parent-pair bred in UV-treated water.
This system has been selected as an internationally
accepted species.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

no

Test conditions

Hardness:

After aeration the hardness was 250 mg CaC03 per litre.

Test temperature:

20°C

pH:

7.7

Dissolved oxygen:

ISO-medium, aerated until the dissolved oxygen
concentration had reached saturation and the pH had
stabilised.

Salinity:

ISO-medium, formulated using Milli-RO water (tapwater
purified by reverse osmosis; Millipore Corp.,
Bedford, Mass., USA) with the following composition:
CaCI2.2H20 293.8 mg/I
MgS04.7H20 123.3 mg/I
NaHC03 64,8 mg/I
KCI 5.8 mg/I

Nominal and measured concentrations:

The applicability of TOC-analyses was tested in an additional experiment. Test solutions of 10
and 100 mg/I were prepared and kept under the same conditions as used for the main stUdy,
except that no fish were exposed. The results showed that concentrations based on TOe were
stable and in agreement with what was expected based on the nominal concentrations and the
organic carbon content of 76%.

Details on test conditions:

96 hours
Static
10 litres, all-glass, containing 9 litres of test solution.
ISO-medium, aerated until the dissolved oxygen
concentration had reached saturation and the pH had
stabilised. After aeration the hardness was 250 mg
CaC03 per litre and the pH was 8.0.
7 fish per concentration and control.
0.39 g fish/litre, Le. 7 fish per 9 litres of test medium
16 hours photoperiod daily applying yellow light.
The test media were aerated between 48 and 72
hours of exposure.
No feeding from 24 hours prior to the test and during
the total test period.
Within % hour after preparation of the test media from
a holding tank with comparable water quality
parameters and pH and temperature differences
between test and holding tank media of less than 0.5
unit and 0.5°G.
At the end of the test the surviving fish were rapidly
killed by exposing them to ca. 1.2% ethylene glycol
monophenylether in water.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

ca. 42 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 32 - 56

Details on results:

The results of measurement of pH and oxygen concentrations are presented. Note
that aeration was applied between 48 and 72 hours of exposure, as the oxygen concentration
tended to drop below the optimum level for testing with carp, i.e. below 5 mg/1. The
temperatures measured during the study in the various test vessels are presented. All test conditions remained within the ranges prescribed by the protocol (pH: 6.0-8.5, constant within 1 unit; temperature 20-24°C, constant within 2°C; oxygen> 60% of air saturation).

Reported statistics and error estimates:

The 72h-LCso was determined using the maximum likelihood estimation method with the probits
of the percentages of dead fish as function of the logarithms of the corresponding
concentrations (Finney, D.J., 1971 : Probit analysis, Cambridge University Press, Cambridge,
U.K., 3rd edition). The 48h and 96h-LCso could not be determined using the maximum likelihood
estimation method with the probits of the percentages of dead fish as function of the logarithms
of the corresponding concentrations (Finney, D.J., 1971: Probit analysis, Cambridge University
Press, Cambridge, U.K., 3rd edition). This was because there was no concentration between
the highest concentration (A) at which 0% mortality and the lowest concentration (B) at which
100% mortality occurred. Instead, the LCso was calculated as (AB)%, with A and B being limits of
the 95% confidence interval. All calculations were based on nominal concentrations.

Any other information on results incl. tables

Sublethal observations / clinical signs:

1. No mortality or abnormal behaviour was observed in the control group.

2. The oxygen concentration was maintained at at least 60% of the air saturation value

throughout the test (> 5 mg/I at 22 QC). Other test conditions (pH and temperature) were

maintained within the limits prescribed by the guidelines.

3. TOC-analysis indicated that recoveries for organic carbon did not decrease by more than

20% below the initial concentration. Although TOC-analysis is not a specific method, these

results indicate that should degradation have occurred, this was far from complete. In that

case degradation should have mainly produced organic degradation products.

4. The 96h-LC50 of the reference chemical for the stock of fish was in agreement with results

obtained previously in our laboratory.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the present test 2,5-Dimethylpyrrole induced no lethal effects in carp at
or below nominally 32 mg/1.
The 96h-LCso was 42 mg/I based on nominal concentrations (95% confidence interval between
32 and 56 mg/I).

Executive summary:

96-Hour Acute Toxicity Study in Carp with 2,5-Dimethylpyrrole.

The study procedure described in this report was based on the OECD guideline No. 203,1992.

In addition, the procedures were designed to meet the test methods of the EEC directive 92/69,

Part C.l, 1992 and the ISO International Standard 7346-1: Static method, 1996.

The batch of 2,5-Dimethylpyrrole tested was a yellowish liquid with a purity of 99.7%.

2,5-Dimethylpyrrole was completely soluble in test medium at the concentrations tested.

Based on the results of a range-finding test a final LCso test was performed with seven carp per

test group exposed to a blank-control and nominal 2,5-Dimethylpyrrole concentrations of 10, 18,

32, 56 and 100 mg/1. Fish were exposed in a static test system for a total of 96 hours. Samples

for Total Organic Carbon (TOC) analysis were taken at the start and the end of the test period.

In addition, samples were taken at intermediate time intervals in case all fish had died in a test

group. TOC-analysis was performed instead of a specific analytical method on request of the

sponsor.

TOC-analysis showed that recoveries for organic carbon were stable during the test period and

in agreement with nominal (83-95%).

The study met the acceptability criteria prescribed by the protocol and was considered valid.

2,5-Dimethylpyrrole induced no lethal effects in carp at or below nominally 32 mg/1.

The 96h-LCso was 42 mg/I based on nominal concentrations (95% confidence interval between

32 and 56 mg/I).