Because spray polyurethane foam insulation is activated and cures on site, it should always be installed by a qualified professional. Some occupants may be sensitive (or could become sensitized) to certain components of spray polyurethane foam insulation, either during application or afterwards. Prior to application, talk to your contractor or medical professional, and research the various insulation products available to determine what is appropriate for you, your home, and your specific project. If you choose to have spray polyurethane foam insulation applied in your home, talk to your contractor about how long you should be out of your home during and after application (usually 24-72 hours).