Choose appropriate fire protection materials, such as fire-rated board, firestop packs, firestop mastic, or fire-resistant mineral wool. Firestop packs should be placed in an orderly sequence. Indoor: Painted steel or galvanized trays. Corrosive/High Humidity:. Scope: Firestopping for busway, cable trays, cables, and trunking passing through walls in enclosed electrical installations. Where cables pass through shafts, walls, slabs, or enter electrical panels or cabinets, openings shall be tightly sealed with firestopping materials in accordance with. Fire resistance is a key factor when selecting cable trays for areas where fire hazards are present. Electrical fires can spread rapidly through the cables within a tray system, which is why choosing the right material for your cable tray is paramount in reducing the risk. These systems prevent fire and smoke from spreading through open cable pathways, maintaining circuit integrity and code. Effective protection of cable systems around the world: our tried-and-tested FLAMMOTECT-A and DG-CR 0.