Recessed ceiling lights should be rated for which type of installation if placed against insulation?

Recessed ceiling lights that are installed in close proximity to insulation must be rated as IC, which stands for "Insulation Contact." This rating is crucial because IC-rated fixtures are designed specifically to operate safely in environments where they come into direct contact with insulation materials.

Using IC-rated fixtures helps prevent potential overheating and reduces the risk of fire hazards that could arise if a non-IC fixture, which isn’t tested for such conditions, is improperly installed near insulation. The IC rating indicates that the light fixture has been tested and meets safety standards for thermal insulation contact, ensuring that it can handle the heat generated during operation without damaging the surrounding materials or creating unsafe conditions.

In contrast, non-IC fixtures should not be located where they could touch or be covered by insulation, as they don't have the same safety features and can lead to overheating. High voltage and low voltage classifications relate more to the electrical characteristics of the fixtures than their ability to manage heat around insulation, and thus they don't pertain directly to this safety concern regarding insulation contact.