This document specifies general conditions for the analysis of polymers using thermogravimetric techniques. It is applicable to liquids or solids. Solid materials may be in the form of pellets, granules or powders. Fabricated shapes reduced to appropriate specimen size may also be analysed by this method. This document establishes methods for the investigation of physical effects and chemical reactions that are associated with changes of mass. Thermogravimetry can be used to determine the temperature(s) and rate(s) of decomposition of polymers, and to measure at the same time the amounts of volatile matter, additives and/or fillers they contain. Thermogravimetric measurements can be carried out in dynamic mode (mass change versus temperature or time under programmed temperature conditions) or isothermal mode (mass change versus time at constant temperature). Thermogravimetric measurements can also be carried out using different testing atmospheres, e.g. to separate decomposition in an inert atmosphere from oxidative degradation.