This part of ISO 8873 specifies minimum requirements and test methods for spray-applied polyurethane rigid cellular plastic, used as a thermal insulation for both building, whether applied on a building site or in a prefabrication (manufacturing) facility, and non-building applications. The material is also known as in-situ thermal insulation. The spray-applied polyurethane rigid cellular plastic thermal insulation is not to be used when the continuous service temperature of the substrate is outside the range of to . The test methods used to determine the material properties provide a means of comparing different cellular plastic thermal insulations. They are intended for use in specifications, product evaluations and quality control. They are not intended to predict end-use product performance. Spray-applied polyurethane rigid cellular plastics are to be applied (installed) in accordance with the manufacturer's instructions and the requirements of ISO 8873-2. Applications, requirements for applications and limitations of use are included in ISO 8873-2.