Pyridine-2-carbaldehyde

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:

1 October - 5 October 2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP - guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

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)

Remarks:

(The Department of Health of the Government of the United Kingdom)

Test material

Test material information

Constituent 1

Reference substance name:

Pyridine-2-carbaldehyde

EC Number:

214-333-6

EC Name:

Pyridine-2-carbaldehyde

Cas Number:

1121-60-4

Molecular formula:

C6H5NO

IUPAC Name:

pyridine-2-carbaldehyde

Test material form:

other: liquid

Details on test material:

- Name of test material (as cited in study report): Pyridine-2-aldehyde
- Physical state: light yellow liquid
- Storage condition of test material: room temperature , in the dark until 31 July 2001 , thereafter approximately 4°C , under nitrogen , in the dark

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

The concentration and stability of the test material in the test solutions were verified by chemical analysis at 0, 24 and 96 hours .
- Concentrations: 1.0 , 1.8 , 3.2 , 5.6 and 10 mg/l
- Sample storage conditions before analysis: Duplicate samples and samples at 24 (fresh media), 48 and 72 hours (fresh and old media) were taken and stored frozen (approximately -20°C) for further analysis if necessary.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: An amount of test material (500 mg) was dissolved in dechlorinated tap water with the aid of ultrasonication for approximately 10 minute and the volume adjusted to 1 litre to give the 500 mg/l stock solution. Aliquots of this stock solution (40, 72, 128, 224 and 400 ml) were each separately dispensed into a final volume of 20 litres of dechlorinated tap water with the aid of a flat bladed mixer for approximately 1 minute to give the 1.0,1.8, 3.2, 5.6 and 10 mg/l test concentrations.
Prior to use the stock solution was inverted several times to ensure adequate mixing and homogeneity.
The Sponsor indicated that the test material might be light sensitive and therefore the test material was weighed under a non-actinic light source.

Test organisms

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: rainbow trout
- Source: Brow Well Fisheries Limited, Hebden, near Skipton, Yorkshire, UK , maintained in-house since 14 September 2001.
- Age at study initiation : juvenile
- Length at study initiation (mean): 5.1 cm (sd = 0.2)
- Weight at study initiation (mean): 1.03 g (sd = 0.12)
- Feeding during test : none

ACCLIMATION
- Acclimation period: 19 September 2001 to 1 October 2001
- Acclimation conditions : same as test
- Type and amount of food: commercial trout pellets
- Health during acclimation : There was zero mortality in the 7 days prior to the start of the test

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test conditions

Hardness:

appr. 100 mg/l as CaCO3

Test temperature:

14 °C , measured at test start and after each test media renewal at 24 , 48 and 72 hours .

pH:

7.4 - 8.0 , measured at test start and after each test media renewal at 24 , 48 and 72 hours .

Dissolved oxygen:

9.0 - 9.8 mg O2/l (87-95% of saturation) , measured at test start and after each test media renewal at 24 , 48 and 72 hours .

Nominal and measured concentrations:

see table 1(at any other information on materials incl. tables)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type : The test vessels were covered to reduce evaporation
- Material, size, headspace, fill volume: glass tanks , containing 20 l test solution
- Aeration : The test vessels were aerated via narrow bore glass tubes.
- Renewal rate of test solution : daily
- No. of organisms per vessel : 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.52 g bw/l

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Laboratory tap water was dechlorinated by passage through an activated carbon filter (Purite Series 500) and partly softened (Elga Nimbus 1248D Duplex Water Softener) . After dechlorination and softening the water was passed through a series of computer controlled plate heat exchangers to achieve the required temperature.

OTHER TEST CONDITIONS
- Light intensity : The test vessels were shielded from the light as information provided by the Sponsor indicated the test material might be of a light sensitive nature.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

TEST CONCENTRATIONS

- Range finding study
- Test concentrations : 1.0 , 10 and 100 mg/l
- Results used to determine the conditions for the definitive study : The results showed no mortalities at the test concentration of 1.0 mg/l. However, mortalities were observed at 10 and 100 mg/l . Based on this information test concentrations of 1.0, 1.8, 3.2, 5.6 and 10 mg/l were selected for the definitive study.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% confidence limit : 1.0 - 1.8 mg/l

Effect concentrations 2

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

Mortality data :
Cumulative mortality data from the exposure of rainbow trout to the test material during the definitive study are given in Table 2 .

Sub-lethal effects :
Sub-lethal effects of exposure were observed at test concentrations of 1.8 mg/l and above. These responses were increased pigmentation and swimming at the bottom of the test vessels with increased pigmentation (see Table 3).

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

The study was performed in compliance with UK GLP standards (Schedule 1, Good Laboratory Practice Regulations 1999 (SI 1999/3106)). These Regulations are in accordance with GLP standards published as OECD Principles on Good Laboratory Practice

Conclusions:

The study is regarded as a valid guideline study with certificated GLP compliance. The acute toxicity of the test material to the freshwater fish rainbow trout (Oncorhynchus mykiss) has been investigated and gave a 96-Hour LC50 value of 1.3 mg/l with 95% confidence limits of 1.0 – 1.8 mg/l. The No Observed Effect Concentration was 1.0 mg/l.
The experimental results for fish and daphnids (EC50 (48h) = 6.96 mg/L) confirm the assumption made based on the calculated results, that fish is the most sensitive species.
Based on these results, the test item does not need to be classified as acute toxic to the aquatic environment. With regard to chronic toxicity, the substance also does not need to be classified as not all classification criteria for Category Chronic 2 are fulfilled:
96 hr LC50 (for fish) >1 to ≤10 mg/L and/or -> fulfilled
48 hr EC50 (for crustacea) >1 to ≤10 mg/L and/or -> fulfilled
and the substance is not rapidly degradable (NOT fulfilled, substance is rapidly biodegradable) and/or the experimentally determined BCF ≥ 500 (or, if absent, the log Kow ≥ 4) (Not fulfilled; logPow = 0.714).

Executive summary:

The acute toxicity to fish of Pyridine-2-aldehyde was tested according to OECD guideline 203 and EU Method C.1 in a semi-static freshwater test with rainbow trout (Oncorhynchus mykiss) as test organisms, which is a freshwater fish representative of a wide variety of natural habitats, and can therefore be considered as an important non-target organism in freshwater ecosystems. The study was conducted under certificated GLP compliance. Following a preliminary range-finding study, fish were exposed, in groups of ten, to an aqueous solution of the test material over a range of concentrations of 1.0, 1.8, 3.2, 5.6 and 10 mg/l for a period of 96 hours under semi-static test conditions. The number of mortalities and any sub-lethal effects of exposure in each test and control vessel were determined 3 and 6 hours after the start of exposure and then daily throughout the study until termination after 96 hours.

The 96-Hour LC50 based on nominal test concentrations was 1.3 mg/l with 95% confidence limits of 1.0 – 1.8 mg/l. The No Observed Effect Concentration (NOEC) was 1.0 mg/l.

Analysis of the test solutions at 0, 24 and 96 hours showed measured test concentrations to range from 84% to 112% of nominal values and so the results are based on nominal test concentrations only.