An IC, or "insulated contact," rating on a recessed light fixture indicates the fixture is designed to be safely installed with zero clearance from the fiberglass or cellulose insulation used within the plenum or attic space above the fixture. Superior insulation of heat and the lower wattage lamps required in IC-rated fixtures make them more energy efficiency and the most common type used in residential applications. Determining whether your recessed fixtures are IC rated is an easy procedure that will quickly establish the maximum bulb size for the fixture.
Things You'll Need
Access the recessed light fixture using a stepladder.
Remove the recessed light fixture's surface trim ring. There are two common types of trim rings on most recessed fixtures: a spring retention type held in place with an internal spring clip that is removed by pulling downward on the trim ring to detach the spring clips, and a threaded trim ring removed by twisting the ring counterclockwise to detach it from the housing's rim.
Look into the inner bulb chamber of the fixture to find the Underwriters Laboratory rating sticker, which is typically on the metal housing near the opening. This sticker will define the fixture's rating (IC or NON-IC) and the approved maximum bulb wattage. You may need to use a flashlight to find and read the rating label.