This paper discusses important safety-oriented code requirements that tend to be overlooked in mechanical design. There are critical safetyorservice-related design practices applicable to building mechanical systems but frequently overlooked by engineers, design-build specialists,contractors, and even code officials. Best practices for operator safety in equipment rooms, OSHA requirements, and VRF refrigerantsafety requirements are reviewed. Specific topics include guardrails near roof-mounted equipment, requirements for insulation on hot surfaces,separate ventilation for differing occupancies, interior stairway enclosure mechanical design, access and aisles around mechanical equipment,and possible hazards of placing chillers and boilers in the same room.