Choose the right box based on environment (indoor/outdoor), load capacity, and durability. Check for proper IP/NEMA ratings and material quality. It takes the incoming power and safely distributes it to different circuits throughout your building. However, the key to. This subpart contains requirements for fire brigades, and all portable and fixed fire suppression equipment, fire detection systems, and fire or employee alarm systems installed to meet the fire protection requirements of 29 CFR part 1910. This subpart applies to all employments. The requirements of this section apply to the placement, use, maintenance, and testing of portable fire extinguishers provided for the use of employees. Existing commercial buildings may be required to upsize their K ox Box if outgrown by increased number o keys.