This part of ISO 11681 specifies safety requirements and their verification for the design and construction of portable combustion-engine, hand-held chain-saws for tree service, having a maximum mass, without guide bar or saw chain and with tanks empty, equal to 4,3 kg, and designed for use by a trained operator for pruning and dismantling standing tree crowns. It gives methods for the elimination or reduction of hazards arising from the use of the chain-saws. In addition, it specifies the type of information on safe working practices to be provided by the manufacturer. It deals with all significant hazards. The environmental aspects, except for noise, have not been considered. Chain-saws covered by this part of ISO 11681 are designed to be operated with the right hand on the rear handle and the left hand on the front handle by persons having read and understood the safety requirements in the instruction handbook and using the appropriate personal protective equipment (PPE). This part of ISO 11681 is not applicable to chain-saws manufactured before its date of publication.