OECD Guidelines for the Testing of Chemicals, Section 1
- 2074-5753 (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 physical-chemical properties.
Test No. 111: Hydrolysis as a Function of pH
- 23 Nov 2004
- 9789264069701 (PDF)
This Test Guideline describes a laboratory test method to assess abiotic hydrolytic transformations of chemicals in aquatic systems at pH values normally found in the environment (pH 4 – 9). This Guideline is designed as a tiered approach; each tier is triggered by the results of the previous tier.Sterile aqueous buffer solutions of different pH values (pH 4, 7 and 9) are treated with the non-labelled or labelled test substance (only one concentration, which should not exceed 0.01 M or half of the saturation concentration). They are incubated in the dark under controlled laboratory conditions (at constant temperatures). After appropriate time intervals, buffer solutions are analysed for the test substance and for hydrolysis products. The preliminary test should be carried out for 5 days at 50 ± 0.5°C and pH 4.0, 7.0 and 9.0. The second tier consists of the hydrolysis of unstable substances, and the third tier is the identification of hydrolysis products. The higher Tier tests should be conducted until 90 % hydrolysis of the test substance is observed or for 30 days whichever comes first.