This International Standard establishes requirements and test methods for portable chain-saw and brush-cutter exhaust system characteristics related to fire ignition potential. The requirements include: — maximum temperatures for exhaust gases and exhaust system surfaces; — maximum opening size for screen-type spark arresters; — restriction on debris accumulation; and — durability and serviceability requirements. The test methods include: — uniform procedures for measuring exhaust gas and exhaust system surface temperatures; and — a procedure to evaluate opening size for screen-type spark arresters. NOTE 1 Means of limiting the size of carbon particle emissions, other than screen-type spark arresters, are not covered by this International Standard.