Put out by the National Fire Protection Association, the new NFPA 70E standard for Electrical Safety, covers all the guidelines relating to electrical work. The section on safety-related work practices will soon be adopted by OSHA and will be mandatory.
The long and short of it is that, depending on the hazard, a different level of protection is required against arc-flash. Once you have determined the level of protection that you require, you will need to get the appropriate clothing. This can vary from Level 1 to Level 4.
To shop by level of protection use the "Quick Links" at the bottom of this page.