Registration Dossier

Ecotoxicological information

Toxicity to aquatic plants other than algae

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
toxicity to aquatic plants other than algae
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
documentation insufficient for assessment
Principles of method if other than guideline:
No information available.
GLP compliance:
not specified
Test organisms (species):
Lemna minor
Details on test organisms:
TEST ORGANISM
- Common name: Duckweed
- L. minor was cultured at 25°C in an aquarium using the culture solution recommended by the US EPA (US EPA, 1989) under continuous illumination of 11000 Lux light from an overhead fluorescent lamp. The culture condition was non-axenic. L. minor fronds of similar size and shape were selected for exposure.
Test type:
not specified
Water media type:
freshwater
Limit test:
no
Total exposure duration:
96 h
Test temperature:
27 +2°C

Nominal and measured concentrations:
0, 1000, 1800, 3200, 5600 mg/L (nominal)
Details on test conditions:
TEST SYSTEM
- Test vessel: culture dishes (9 cm diameter)
- Type: closed
- Renewal rate of test solution (frequency/flow rate): daily
- No. of organisms per vessel: 10 fronds
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- After 96 h exposure all the fronds in one container were put into a glass grinder containing 4ml 90% acetone (10% distilled water). The homogenate was transferred into one centrifuge tube of 10 ml after being grounded for 5 min, then 1 ml 90% acetone was added, and the solution was refrigerated for 72 h at 4°C to extract chlorophyll A. The homogenate was then centrifuged at 2000 rev min- 1 for 10 min. The optical density (00) values of the supernatant at 663 nm, 645 nm, 630 nm and 750 nm, respectively, were measured using a quartz glass curette with 1 cm thickness by a spectrophotometer (model 721, Shanghai Science Instrument Co., Shanghai, China).


OTHER TEST CONDITIONS
- Light intensity and quality: continuous illumination of 11000 Lux light from an overhead fluorescent lamp.

EFFECT PARAMETERS MEASURED: Growth inhibition
- Chlorophyll measurement: The chlorophyll A amount in every test container was indicated by the concentration of chlorophyll A in supernatant (Ca). Ca was calculated following Zhou (1990)
Duration:
96 h
Dose descriptor:
IC50
Effect conc.:
3 663 mg/L
Nominal / measured:
nominal
Duration:
96 h
Dose descriptor:
NOEC
Effect conc.:
1 000 mg/L
Nominal / measured:
nominal
Basis for effect:
other: Chlorophyll a concentration
Duration:
96 h
Dose descriptor:
NOEC
Effect conc.:
1 000 mg/L
Nominal / measured:
nominal
Basis for effect:
growth rate
Executive summary:

Tong and Hongjun (1997) reported a 96 -hour IC50 value of 3663 mg/L for acetonitrile in Duckweed, (Lemna minor).

Description of key information

Tong and Hongjun (1997) reported a 96 -hour IC50 value of 3663 mg/L for acetonitrile in Lemna minor (Duckweed).

Key value for chemical safety assessment

EC50 for freshwater plants:
3 663 mg/L
EC10 or NOEC for freshwater plants:
1 000 mg/L

Additional information

Tong and Hongjun (1997) reported a 96 -hour IC50 value of 3663 mg/L and a NOEC of 1000 mg/L for acetonitrile in Lemna minor (Duckweed).