Isonicotinaldehyde

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2 June - 6 June 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP - guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Isonicotinaldehyde

EC Number:

212-832-3

EC Name:

Isonicotinaldehyde

Cas Number:

872-85-5

Molecular formula:

C6H5NO

IUPAC Name:

pyridine-4-carbaldehyde

Test material form:

other: liquid

Details on test material:

- Name of test material (as cited in study report) : Pyridine-4-aldehyde
- Physical state : clear yellowish liquid
- Analytical purity : 98,7% (GC)
- Lot/batch No. : 1120126/001
- Storage condition of test material : Refrigerator at approx. 4°C , in the dark , under nitrogen

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations : The actual concentrations of the test substance in the test media were determined by HPLC before the test and after 48 hours .

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method : Immediately before the beginning of the test the highest concentration of nominal 100 mg/l solution was prepared by dissolving 26,5 mg test substance in 250 ml reconstituted water . The lower concentrations ( 10 , 18 , 32 and 56 mg/l ) were then obtained by diluting with reconstituted water .

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name : water flea
- Source : Neonates of Daphnia magna were obtained by hatching ephippia supplied in the microbiotest "Daphtoxkit F TM" (Daphnia magna ; MicroBio Tests Inc. , Industriezone "De Prijkels" , Venecoweg 19 , 9810 Nazareth , Belgium )
- Age at study initiation : < 24 h
- Feeding during test : none

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

250 mg CaCO3/l

Test temperature:

approximately 20°C troughout the test

pH:

between 7,8 and 7,9 in the substance solutions

Dissolved oxygen:

at least 7,9 mg/l

Nominal and measured concentrations:

see table 1 at "Any other information on materials and methods incl. tables"

Details on test conditions:

TEST SYSTEM
- Test vessel : Disposable multiwell test plates with 30 test wells with a transparent lid , provided with the testkit . Each plate has 4 wells (replicates A,B,C,D) for the control and for 5 concentrations .
- Aeration : no extra aeration , but slight circulation of air is still possible when the lid of the test plate is closed .
- No. of organisms per vessel : 5
- No. of vessels per concentration (replicates) : 4
- No. of vessels per control (replicates) : 4


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water : reconstituted water according ISO 6341 . The water was aerated and the pH , the dissolved oxygen concentration and the water hardness were checked befor using .

OTHER TEST CONDITIONS
- Light : 16 hours artificial light

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : 24 and 48 hours after beginning of exposure the neonates were observed for their swimming behaviour .

TEST CONCENTRATIONS
- Test concentrations : 10 , 18 , 32 , 56 and 100 mg/l

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

60 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: swimming behaviour

Remarks on result:

other: 95% CL : 49 - 72 mg/l

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

49 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: swimming behaviour

Remarks on result:

other: 95% CL : 41 - 59 mg/l

Effect concentrations 3

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: swimming behaviour

Effect concentrations 4

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: swimming behaviour

Effect concentrations 5

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: swimming behaviour

Effect concentrations 6

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: swimming behaviour

Details on results:

As some daphnids in the test substance groups were trapped at the water surface there is a possible influence of the test substance to the water surface tension .

Any other information on results incl. tables

Immobilisation 24 hours after the start of exposure

Group (mg/l)	Concentration (mg/l)	Immobilised neonates (trapped at the water surface) / total number of neonates
		Number per replicate				Total number	Total %
		A	B	C	D
K	0	0 / 5	0 / 5	0 / 5	0 / 5	0 / 20	0
C1	10	0 / 5	0 / 5	0 / 5	0 / 5	0 / 20	0
C2	18	0 / 5	0 / 5	0 / 5	1 / 5	1 / 20	5
C3	32	1 / 5	1 / 5	0 / 5	0 / 5	2 / 20	10
C4	56	2 (2) / 5	2 (1) / 5	2 / 5	3 (1) / 5	9 / 20	45
C5	100	4 (2) / 5	4 (2) / 5	4 (1) / 5	5 (4) / 5	17 / 20	85

Immobilisation 48 hours after the start of exposure

Group (mg/l)	Concentration (mg/l)	Immobilised neonates (trapped at the water surface) / total number of neonates
		Number per replicate				Total number	Total %
		A	B	C	D
K	0	0 / 5	0 / 5	0 / 5	0 / 5	0 / 20	0
C1	10	0 / 5	0 / 5	0 / 5	0 / 5	0 / 20	0
C2	18	0 / 5	0 / 5	1 / 5	1 / 5	2 / 20	5
C3	32	1 (1) / 5	1 (1) / 5	0 / 5	1 / 5	3 / 20	15
C4	56	2 (2) / 5	3 (2) / 5	3 / 5	3 (2) / 5	11 / 20	55
C5	100	5 / 5	5 / 5	5 / 5	5 / 5	20 / 20	100

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

At the end of the test the measured concentrations of Pyridine-4-aldehyde were between 87 and 99% of the actual starting concentration ; Immobilisation of control group daphnids was 0% ; no control daphnids trapped at the water surface

Conclusions:

The study was conducted under GLP compliance and a well documented study report is available. The acute toxicity of pyridine-4-aldehyde to daphnia magna was determined in a 48 hours static test . The 48 h EC50 value was 49 mg/l (95% CL : 41 - 59 mg/l)

Executive summary:

The acute toxicity to aquatic invertebrates of pyridine-4-aldehyde was tested according to EU Method C.2 (Acute Toxicity for Daphnia) in a static freshwater test with Daphnia magna as test organisms, which is a freshwater invertebrate representative of a wide variety of natural habitats, and can therefore be considered as an important non-target organism in freshwater ecosystems. Neonates of Daphnia magna, hatched from ephippia and not more than 24 hours old, were exposed to five concentrations of the test substance (10, 18, 32, 56 and 100 mg test substance / L) in reconstituted water according ISO 6341. A negative control group was exposed to reconstituted water only. 20 daphnids, divided into 4 replicates (5 daphnia each), were used for each test substance group and for the control group. No aeration was performed and the test solutions were not renewed during the exposure period. The vessels were covered and maintained at ca. 20°C with a photoperiod of 16 h light for a test duration of 48 hours. No reference substance is required in accordance to the test guideline. The EC50 value was determined as 49 mg/L with 95 % Confidence limits of 41 - 59 mg/L. High Performance Liquid Chromatography (HPLC) was the analytical method of choice.