Guaiacol

Toxicity to terrestrial plants

Administrative data

Endpoint:

toxicity to terrestrial plants: short-term

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Despite the authors stated, this study was not in accordance with the OECD guideline since filter paper was used instead of soil. No information was available about the test substance.

Data source

Reference

Reference Type:

publication

Title:

Mechanism-based quantitative structure-phytotoxicity relationships comparative inhibition of substituted phenols on root elongation of Cucumis sativus

Author:

Wang X., Wang Y., Chunsheng L. and Wang S.H.

Year:

2002

Bibliographic source:

Arch. Environ. Contam. Toxicol., 42 : 29-35

Materials and methods

Principles of method if other than guideline:

Root elongation inhibition method in accordance with the OECD guideline.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Guaiacol

EC Number:

201-964-7

EC Name:

Guaiacol

Cas Number:

90-05-1

Molecular formula:

C7H8O2

IUPAC Name:

Phenol

Details on test material:

The test substance of sufficient purity was provided by the Department of Chemistry, Nanjing University.

Test organisms

Species:

Cucumis sativus

Details on test organisms:

The seeds of Cucumis sativus were employed for test and were purchased commercially. The seeds were sterilized with 0.1% NaClO solution for 20 min., soaked for 10 min. and washed three times with deionised water prior to use.

Study design

Test type:

seed germination/root elongation toxicity test

Study type:

laboratory study

Substrate type:

filter paper

Total exposure duration:

2 d

Test conditions

Details on test conditions:

The stock solution of test substance has been prepared by adding the accurately weighed chemical to dilution water (deionised water) and stirring for a minimum of 20 hours.
Range-finding tests were performed to determine the range of the test solutions and the dilution factors.
The test were conducted using 100x15 mm disposable Petri dishes and Whatman No.1 filter paper.
Fifteen pre-treated, undamaged, and plump seeds of almost identical size were placed evenly on the filter paper in each dish that was filled with 5 mL test solution or deionised water in the control.
The dishes were sealed with Parafilm during the period of incubation to avoid the test substance evaporation.
Six concentrations in geometric series were set, ranging from no effect to 100% inhibition concentration, and four replicates were set for each concentration.
The pH value of each solution was measured by using PHS23-pH meter.
Solutions were renewed every 12 hours to achieve semi-static exposure.
Deionised water without test compounds, served as control.
After 48 hours of incubation in the dark at 25 +/- 1°C, the root elongation of each seed was measured to 1 mm and RC50 (in mg/L) was calculated by the log-linear regression analysis in STATISTICA software.
The Quantitative Structure-Activity Relationship was carried out in parallel to estimate the Log 1/RC50 with physicochemical descriptors of guaiacol (solubility, Log Kow, pH and pKa).

Results and discussion

Effect concentrations

Species:

Cucumis sativus

Duration:

2 d

Dose descriptor:

EC50

Effect conc.:

201.33 other: mg/l

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Root elongation inhibition.

Details on results:

- Element value : The EC50 was measured at 25°C and pH 6.21.
- Biological observation in the control test : The germination rate root elongation in the control test was investigated to observe the reproducibility and stability of the germination rate and root elongation of Cucumis sativus.
The average germination rate was 81.26 +/- 4.45% and the average root length was 21.70 +/- 2.3 mm for the control test on 2 days.
- Biological observation with the test substance : No information was available.