This part of ISO 11681 gives safety requirements and measures for their verification for the design and construction for tree service of portable, combustion-engine, hand-held chain-saws having a maximum mass without guide bar and saw chain and with tanks empty of 4,3 kg, intended to be used, with the right hand on the rear handle and left hand on the front handle, by a trained operator, having read and understood the safety requirements provided in the instruction handbook, for pruning and dismantling standing tree crowns, using the appropriate personal protective equipment (PPE). Methods for the elimination or reduction of hazards arising from the use of these machines and the type of information on safe working practices to be provided by the manufacturer are specified. This part of ISO 11681 deals with all significant hazards, hazardous situations and hazardous events relevant to these machines when they are used as intended and under conditions of misuse which are reasonably foreseeable by the manufacturer. NOTE See Annex B for a list of significant hazards. This part of ISO 11681 is applicable to chain-saws manufactured after its date of publication.