This International Standard is applicable to fully insulating spliced or hook ladders with extension or having a combination of insulating and conductive sections and used for live working on a.c or d.c. electrical installations at 1000 V and above for a.c. and 1500 V and above for d.c. The ladders are classified functionally as Category 1 and Category 2. This standard concerns only ladders made of synthetic material. These ladders are used, to provide access, generally on overhead line structures and to facilitate live working, either hot stick, barehanded or a combination of both.