Introduction Lighting equipment that is permanently installed in buildings needs to meet specific standards to obtain safety listings. Recessed luminaires are lighting fixtures can be divided into two classifications: ones that are rated only for use with clear space around them and those that can be in partial or full contact with building insulation. The latter are normally referred to as IC rated. There are numerous luminaire types on the market that have been tested and are rated for use in contact with insulation material utilized in building construction. However@ the testing procedures and assumptions of this rating are associated with blown-in or batting-type dry insulation. The insulation material which covers the luminaire reduces heat flow from the luminaire that would normally be transferred to the surrounding air. Equipment safety testing takes such reduced thermal flow into account during the testing to achieve an IC rating. The use of liquid spray-in place expanding foam has started to see the application as another type of insulation used in buildings in the past few years. Although it has excellent insulating capabilities@ its characteristics are markedly different than blown-in insulation. The following information reviews practical aspects of applying spray foam insulation that may come into contact with luminaires in various building applications.