California Code, Health and Safety Code - HSC § 19967

“Building component” means any subsystem, subassembly, or other system designed for use in, or as part of, a structure, which may include structural, electrical, mechanical, plumbing, and fire protection systems and other systems affecting health and safety. However, “building component” does not include appliances or equipment, such as heaters, stoves, refrigerators, or air conditioners, which have been listed and labeled by an approved testing and listing agency.