We currently have two styles of Slim downlights in our warehouse: metal and sturdy plastic junction boxes. The new style of plastic J-Boxes should not be installed in polystyrene foam (whether board or bead/loose fill style). As a precaution we recommend you do not use polystyrene foam insulation, because it can catch fire at 150° F, whereas other insulation types catch fire at 400° F (UL/ETL test for IC rating includes this).In addition, be sure to wear protective gloves when maintaining any recessed cans, Slims with J-Boxes, or retrofit downlights. The recommendation to wear gloves also applies to handling any plastic parts, since human skin has a lower heat tolerance level and the durable plastics used in our recessed LED lights can run at 90° F.Installed correctly, our IC Rated recessed lighting can be placed adjacent to insulation in ceiling spaces without fire issues.