Phthalimide

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Source: National Institute for Environmental Studies (Japan)
- Pretreatment of parent: 14 days
- Age at study initiation: less than 24 h old

ACCLIMATION
- Acclimation period: yes
- Acclimation conditions: same as test
- Type and amount of food: Chlorella regularis, 0.1-0.2 mgC/day/daphnia

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

224 mg/l as CaCO3

Test temperature:

19.4 - 20.2 °C

pH:

7.2 - 7.5

Dissolved oxygen:

7.8 - 8.8 mg/L

Nominal and measured concentrations:

Nominal concentrations: 0, 3.7, 6.7, 12.0, 21.6, 38.9, 70.0 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- glass vessel, 100 mL net volume
- Aeration: none
- Renewal rate of test solution: none
- Feeding during test: none
- No. of organisms per vessel: 5 daphnia
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): no data

TEST MEDIUM / WATER PARAMETERS
- Source of dilution water: Elendt M4 (in accordance with OECD TG211 Annex 2)
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: no data
- Photoperiod: 16h-8h light-dark cycle by room light
- Light intensity: no data

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

46 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

10.5 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.:

20.8 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Results with reference substance (positive control):

Potassium dichromate (48 h EC50 = 0.84 mg/l)

CONCENTRATIONS
nominal                measured concentration (mg/l)
concentration            (percentage of nominal)
  (mg/l)          0 h  fresh      48 h expired   geom.mean 
-----------------------------------------------------------
control          <0.1            <0.1            <0.1
  3.7             3.0 (81.1)      1.4 (37.8)      2.0 (54.1)
  6.7             5.2 (77.6)      2.6 (38.8)      3.7 (55.2)
 12.0             9.4 (78.3)      4.7 (39.2)      6.6 (55.0)
 21.6            16.8 (77.8)      6.6 (30.6)     10.5 (48.6)
 38.9            30.3 (77.9)     19.1 (49.1)     24.1 (62.0)
 70.0            54.7 (78.1)     38.6 (55.1)     46.0 (65.7)
-----------------------------------------------------------
As the half-life of this substance in water is 56.7 h at 25°C and pH 7  (See section 3.1.2), almost all measured concentrations were much lower  than the nominal ones. Therefore, geometric mean measured values were  used for calculations.

EFFECTS (immobilisation)
24 h EC50  = 31.0 mg/l

measured       cumulative number of immobilized
concentration    daphnid (percentage of immobility)
 (mg/)              0 h           48 h
---------------------------------------------------------- 
control               0 ( 0)         0 ( 0)
  2.0                0 ( 0)         0 ( 0)
  3.7                0 ( 0)         0 ( 0)
  6.6                0 ( 0)         0 ( 0)
 10.5                0 ( 0)         0 ( 0)
 24.1                2 (10)        13 (65)
 46.0               20 (100)       20 (100)
----------------------------------------------------------

Executive summary:

With Daphnia magna a test on acute toxicity was performed according to the OECD TG 202, and the principles of GLP. The recovery rates were less than 80 % at the end of the test, for that reason, the 48 h mean measured concentrations were derived by calculating the geometric mean from the measured values at 0 and 48 h, resulting in an 48 h-EC₅₀of 20.8 mg/l (EA Japan, 1999).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

20.8 mg/L