This International Standard establishes a consistent, reproducible means of evaluating characteristics of falling-object protective structures (FOPS) under loading, and prescribes performance requirements for a representative specimen under such loading. It is applicable to mobile or self-propelled, specially designed forestry machines as defined in ISO 6814. NOTE Research work is being done to develop a test method and criteria for certain polycarbonate materials and constructions where the present requirement levels may not be adequate.