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Is your SDS classification accurate?

Posted Date:2023/11/15

1. The concept of "classification"

The Globally Harmonized System uses the term "hazard classification" to indicate that it considers only the inherently hazardous properties of a substance or mixture.

There are only three steps to risk classification, namely:

(a) Determining data relating to the hazard of the substance or mixture;

(b) Then review the data to identify the risks associated with the substance or mixture; and

(c) Determine whether to classify the substance or mixture as a hazardous substance or mixture by comparing the data with an agreed standard for hazard classification and, as appropriate, determine the level of risk.

2. Classification standard

The classification criteria for substances and mixtures are described in parts 2, 3 and 4 of the GHS document, where each criterion addresses a specific hazard class or a group of closely related hazard classes. For most hazard classes, the proposed mixture classification procedure is based on the following sequence;

(a) If test data are available for the whole mixture, the classification of the mixture will always be based on that data;

(b) If the mixture itself does not have test data, then the bridging principles contained and explained in each specific chapter should be considered to see whether they permit the classification of the mixture; In addition, in terms of health and environmental risks,

(c) Where (1) the test data for the mixture itself are not available and (2) the available information is insufficient to apply the above bridging principles, the mixture can only be classified using the agreed methodology described in each chapter to estimate its risk on the basis of known information.

In most cases, the risk classification of germ cell mutagenicity, carcinogenicity and reproductive toxicity cannot be expected for all mixtures. Therefore, for these hazard classifications, mixtures are generally classified on the basis of available information on the individual components of the mixture, using the threshold/concentration method in the chapters. The classification may be modified according to the specific circumstances and on the basis of complete experimental data on mixtures, provided that the relevant data are established in accordance with the requirements of the chapters.

The Globally Harmonized System itself does not require testing of substances or mixtures. Therefore, the globally harmonized System does not require the generation of test data for any hazard category. It is true that some regulatory systems do require data generation (for example, pesticides), but these requirements are not specifically linked to the global harmonized System. The criteria developed for the classification of mixtures will allow the use of data on existing mixtures themselves, and/or similar mixtures, or on the composition of mixtures.

3. Existing data, test methods and test data quality

The classification of substances or mixtures depends both on the standard and on the reliability of the test method on which the standard is based. In some cases, classification is determined by the passage of a specific test (e.g. biodegradation of a substance or mixture component), while in others, interpretation is based on the dose/response curve and observations made during the test. In all cases, test conditions must be standardized so that test results can be reproduced for a given substance, and standardized tests can produce "valid" data for defining the types of hazards involved. In this context, validation is the process of confirming the reliability and relevance of a program for a specific purpose.

Tests to determine hazard characteristics, carried out in accordance with internationally recognized scientific principles, may be used for hazard identification of health and environmental hazards. The criteria for determining health and environmental risks in the Global Harmonized System have no special requirements for test methods and allow the use of different methods, provided that they are scientifically sound, validated in accordance with international procedures and standards relating to risks referred to in the current system and produce mutually acceptable data. The test methods for determining physical hazards are generally clear and are defined in the globally harmonized System.