Phthalaldehyde

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2002-11-11 to 2002-12-11

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

29 December 1992

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Specific details on test material used for the study:

Name: "o-Phthaldialdehyde"
Chemical name: 1,2-Benzene dicarboxyaldehyde
CAS No.: 643-79-8
Molecular formula: C8H6O2
Supplier: DSM Fine Chemicals
Batch No.: OSHO 201
Appearance: Pale yellow scales or powder
Boiling point: 83 °C/1 mbar
Melting range: 54–56 °C
Solubility: in water: 53 g/L at 20 °C; in other solvents: organic solvents
Conditions of storage: Refrigerator, in the dark, may be used under light
Stability at conditions of storage: stable
Expiration date: January 2004

Analytical monitoring:

yes

Vehicle:

no

Remarks:

Reconstituted water

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
Immediately before the beginning of the test a stock solution of 100 mg/L was prepared by dissolving 9.9 mg test substance in 100 mL deionised water. The appropriate concentrations were then obtained by diluting with reconstituted water.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: not specified; neonates less than 24 hours old obtained by hatching ephippia
- Source: Daphtoxkit F (TM) "(Fa. BioMicrotests, Industriezone "De Prijkels", Venacoweg 19, 9810 Nazareth, Belgium), Batch No. of ephippia DM050902
- Age of parental stock (mean and range, SD): not specified
- Feeding during test: none, but fed approx. 2 hours before beginning of the test
- Food type: Suspension of spirulina powder (Fa. MicroBioTests)
- Amount: not specified
- Frequency: not specified

CULTURING
The ephippia were hatched in a petri dish containing reconstituted water in a temperature controlled room at approx. 20–22 °C under continuous illumination of approx. 6,000 Lux. According to Fa. MicroBioTests the largest hatching occurs between 72 and 80 hours and the daphnids were collected, at the latest, 90 hours after initiation of hatching. Approx. 2 hours before beginning of the test, the neonates were fed, as also in traditional cultures the neonates have the opportunity to take up some feed particles. The neonates were collected for test at approx. 87 hours after initiation of hatching.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

Checking for immobility after 24 and 48 hours

Post exposure observation period:

not specified

Hardness:

250 mg CaCO2/L (reconstituted water)

Test temperature:

approx. 21 °C

pH:

7.5-7.9

Dissolved oxygen:

8.3 mg/L

Salinity:

not reported

Conductivity:

not reported

Nominal and measured concentrations:

Nominal: 0.10, 0.18, 0.32, 0.56, 1.00 mg test substance / L in reconstituted water and negative control (reconstituted water only)
Measured (geom. mean): 0.05, 0.07, 0.20, 0.50 and 0.94 mg test substance/L

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. For each concentration, the plates are provided with "rinsing wells" to prevent dilution of the test substance during the transfer of the daphnids from the hatcing petri dish to the test wells. The "rinsing wells" and the wells for the replicates of each concentration and control respectively were filled with 10 mL medium each. For each concentration and for the control at least 20 actively swimming neonates were transferred with a micropipette from the hatching petri dish to the "rinsing well". Then 5 neonates from the "rinsing wells" were transferred to each of the 4 wells of the appropriate concentrations.
- Material, size, headspace, fill volume: 10 mL
- Aeration: No extra aeration, but slight circulation of air is still possible when the lid of the test plate is closed.
- Renewal rate of test solution (frequency/flow rate): no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): not applicable
- No. of vessels per vehicle control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water according to ISO 6341 from Daphtoxkit F (TM) Batch No. ISO D010802
- Culture medium different from test medium: no
- Intervals of water quality measurement: daily

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours artificial light
- Light intensity: 6,000 Lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Immobilisation and mortality checked daily

RANGE-FINDING STUDY
- Test concentrations: A preliminary test with concentrations between 1 and 10 mg/L all daphnids were immobilised in the 1 mg/L concentration
- Results used to determine the conditions for the definitive study: yes. 5 concentrations between 0.1 and 1.0 mg test substance per litre test medium chosen for the test

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

0.05 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.11 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CI: 0.13-0.10

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

0.2 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

0.07 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

0.12 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CI: 0.14-0.11

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

0.5 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Besides immobility and mortality no other effects were reported
- Mortality of control: 0 %
- Other adverse effects control: not reported

Reported statistics and error estimates:

Not reported

- ANALYTICAL RESULTS: After 48 hours of exposure, the actual test substance concentrations were between 18 and 81 % of the actual starting concentrations (concentration-dependent). The effective concentrations were calculated based on geometric means of the actual concentrations at the start and end of the test.

- BIOLOGICAL RESULTS: After 48 h exposure 20 % daphnids were immobilised at an exposure concentration of 0.07 mg/L. At the higher concentrations 100 % of the daphnids were immobilised.

VALIDITY CRITERIA:

- Immobilisation of the test organisms in the control at the end of the test was 0 % and therefore ≤ 10 %.

- Dissolved oxygen concentration in the control and the test item treatments at the end of the test was ≥ 8.3 mg/L and therefore ≥ 3 mg/L.

- pH and temperature were sufficiently stable during the test.

Validity criteria fulfilled:

yes

Conclusions:

In an acute toxicity test according to the EC 92/69 (1992) Daphnia magna was exposed to 0.05, 0.07, 0.20, 0.50, 0.94 mg/L g ortho-phthalaldehyde/L (meas., geom. mean). The 48-h EC50 of ortho-phthaladehyde to D. magna was 0.11 mg/L (95 %C.I.: 0.10–0.13 mg/L).

Executive summary:

The 48-hr-acute toxicity of o-phthaladehyde to Daphnia magna was studied under static conditions according to EEC Commission Directive 92/69, method C.2. Daphnids were exposed to control and test chemical at measured concentration of 0.05, 0.07, 0.20, 0.50, and 0.94 mg/L (geom. mean) for 48 hours.  The actual concentrations of the test substance in the test media, determined after 48 hours of exposure, were between 18 and 81% of the actual starting concentrations. The effective concentrations were calculated based on actual concentrations (geom. mean). Mortality and immobilisation were observed daily. The EC50 after 48 hours was 0.11 mg/L (95 % CI 0.10–0.13 mg/L).

The initial concentration and the maintenance of the exposure concentrations during the test were verified in the analytical part. This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

 

Results synopsis

Test organism age: < 24 h

Test type: Static

EC50 = 0.11 mg a.i./L (95 % C.I.: 0.10–0.13 mg/L)

EC100 = 0.20 mg/L

EC0 = 0.05 mg/L

Endpoint(s) effected: mobility, mortality

Description of key information

In an acute toxicity test according to EEC Commission Directive 92/69, C.2, Daphnia magna were exposed to 0.05, 0.07, 0.20, 0.50, and 0.94 mg ortho-phthalaldehyde/L for 48 hours. The EC50 determined after 48 hours is 0.11 mg/L (95 % CI 0.10–0.13).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.11 mg/L