The use of insulation material in power switchgear requires consideration of many factors not encountered in any other application. This report describes this application in the context of the particular and sometimes hostile switchgear environment. It supplements for the purpose of switchgear application IEEE Standard No.1, "General Principles for Temperature Limits in the Rating of Electrical Equipment for the Evaluation of Electrical Insulation". Included are descriptions of several application classifications, varying with degree of exposure to different stresses, factors of influence of particular concern to switchgear, properties of material which are important and need to be qualified, and some notes on specific materials commonly used in switchgear. In addition to providing useful information on the subject, this report is intended to act as a catalyst in the development of needed relevant standards.