OECD Guidelines for the Testing of Chemicals, Section 2
Effects on Biotic Systems
- 2074-5761 (online)
The OECD Guidelines for the Testing of Chemicals is a collection of about 150 of the most relevant internationally agreed testing methods used by government, industry and independent laboratories to identify and characterise potential hazards of chemicals. They are a set of tools for professionals, used primarily in regulatory safety testing and subsequent chemical and chemical product notification, chemical registration and in chemical evaluation. They can also be used for the selection and ranking of candidate chemicals during the development of new chemicals and products and in toxicology research. This group of tests covers effects on biotic systems.
Test No. 221: Lemna sp. Growth Inhibition Test
- 11 July 2006
- 9789264016194 (PDF)
This Test Guideline is designed to assess the toxicity of substances to freshwater aquatic plants of the genus Lemna (duckweed).
Exponentially growing plant cultures of the genus Lemna (Lemna gibba and Lemna minor usually) are allowed to grow as monocultures in, at least, five concentrations of the test substance over a period of seven days. The objective of the test is to quantify substance-related effects on vegetative growth over this period based on assessments of selected measurement variables. The limit test corresponds to one dose level of 100 mg/L. This study includes measurement of pH, light intensity, concentrations of the test substance, the counting of the frond number and measurement of at least one other variable (total frond area, dry weight or fresh weight). From the average specific growth rates (or yield) recorded in a series of test solutions, the concentration bringing about a specified x % inhibition of growth rate (or yield) is determined and expressed as the ErCx (or EyCx). An additional response variable used is yield. In addition, the lowest observed effect concentration (LOEC) and the no observed effect concentration (NOEC) may be statistically determined.