Mequinol

Toxicity to terrestrial plants

Administrative data

Endpoint:

toxicity to terrestrial plants: short-term

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: The test conditions are not in accordance in the OECD test guideline (the seeds were exposed to solutions of the test substance on filter paper), and the study is not sufficiently described.

Data source

Reference

Reference Type:

publication

Title:

Mechanism-based quantitative structure-activity relationships for the inhibition of substituted phenols on germination rate of Cucumis sativus.

Author:

Wang X, Yu J, Wang Y, Wang L

Year:

2002

Bibliographic source:

Chemosphere, 46(2), 241-250

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The seed germination of Cucumis sativus was measured by a filter paper contact method.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Mequinol

EC Number:

205-769-8

EC Name:

Mequinol

Cas Number:

150-76-5

Molecular formula:

C7H8O2

IUPAC Name:

4-methoxyphenol

Sampling and analysis

Analytical monitoring:

not specified

Test substrate

Vehicle:

not specified

Details on preparation and application of test substrate:

Details on preparation and application of test substrate: 
- Method of application to filter paper (if used): no data
- Method of mixing into soil (if used): no soil used
- Controls: deionized water
- Chemical name of vehicle (organic solvent, emulsifier or dispersant):  no data
- Concentration of vehicle in test medium (stock solution and final test  solution): no data
- Evaporation of vehicle before use: no data

Test organisms

Species:

other: other terrestrial plant: Cucumis sativus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Cucumber
- Plant family: Cucurbitaceae
- Variety: no data
- Source of seed: no data
- Prior seed treatment/sterilization: no data 
- Historical germination of seed (germination of seed lot tested): no data
- Seed storage: no data 

Study design

Test type:

seedling emergence toxicity test

Study type:

laboratory study

Substrate type:

filter paper

Limit test:

no

Total exposure duration:

2 d

Post exposure observation period:

no data

Test conditions

Test temperature:

25+/- 1°C

pH:

no data

Moisture:

not applicable

Details on test conditions:

TEST SYSTEM
- Testing facility: 
- Test container (type, material, size): 100 X 15 mm² disposable petri dishes and Whatman No. 1 
filter paper. 
- Method of seeding: no data 
- Nb. of seeds per container: no data
- Nb. of plants (retained after thinning): no data 
- Nb. of replicates per treatment group: 4
- Nb. of replicates per control:4

GROWTH CONDITIONS
- Photoperiod: Dark
- Relative humidity (%): No data
- Wind velocity: No data
- Air exchange rate: No data
- Watering regime and schedules: solutions were renewed every 12 h to  achieve semi-static exposure.
- Water source/type: deionized water
- Volume applied: 5 mL
- Interval of applications: No data
- Method of application: no data

ACCLIMATION PERIOD: No data

EFFECT PARAMETERS MEASURED  Germination rate

VEHICLE CONTROL PERFORMED: no data

TEST CONCENTRATIONS
- Spacing factor for test concentrations: no data
- Range finding study: no data
- Test concentrations: no data

STATISTIC GC50, concentration at which the average germination rate was 50% of  those in the 
corresponding control, was calculated by the log-linear regression in STATISTICA for Windows 
software (version 5.0).

Nominal and measured concentrations:

6 concentrations ranging from no  effect to 100% inhibition concentration.

Reference substance (positive control):

not specified

Results and discussion

Effect concentrations

Species:

Cucumis sativus

Duration:

2 d

Dose descriptor:

EC50

Effect conc.:

229.3 other: mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Details on results:

SEED GERMINATION
- Percent seed germination: no data
- Root length: not recorded
- Root discolouration/malformation: not recorded
- Results with reference substance valid: not applicable

SEEDLING EMERGENCE
- Percent seedling emergence: no data
- Percent survival: no data
- Plant height: no data
- Dry weight: no data
- Abnormal seed development or appearance: no data

VEGETATIVE VIGOUR: no data 
The average germination rate in the control test ranges from 77% to 88%.
The 50% germination rate inhibition concentration of the test substance:  GC50 = 229.3 mg/L
(R² = 0.966, SE = 3.37)
pH of the test solution on germination rate 50% inhibition concentration:  6.23