Consulting-Specifying Engineer - December 2007 - (Page 49) Codes & Standards Managing risk: a look at the NFPA 99 standard for healthcare facilities BY LARRY WILSON, PE, LEED AP, Senior Vice President, Environmental Systems Design, Chicago he vital signs for the NFPA 99 Standard for Health Care Facilities was released as a first edition in 1984, the current edition in 2005, and the next edition is due in 2010. Its scope covers electrical, gas/ vacuum, and environmental systems for healthcare facilities, including hospitals, laboratories, nursing homes, and limited care facilities. NFPA 99 establishes criteria to minimize fire, explosion, and electrical hazards in healthcare facilities. Amended approximately every three years, NFPA 99 stands as the voice of risk management and prevention for today’s healthcare facilities. But the standard isn’t just a thing unto itself. NFPA 99 complements other major NFPA standards, including the National Electrical Code (NFPA 70), the Life Safety Code (NFPA 101), the National Fire Alarm Code (NFPA 72) and Standard for Emergency and Standby Power Systems (NFPA 110). T • How a healthcare facility’s separate electrical distribution branches—life-safety, critical, and equipment—are used • What alarms are required and the required scope of ongoing testing. But electrical hazards aren’t the only danger in a healthcare environment. Extensive use of gas and vacuum systems present many other risks. Gas and vacuum systems Gas and vacuum systems covered by NFPA 99 include the following: • Oxygen • Medical-surgical vacuum and compressed air • Nitrogen • Nitrous oxide • Carbon dioxide • Waste anesthesia gas disposal • Instrument compressed air. NFPA 99 looks at these systems as combinations of a source and as a distribution network. The sources can be outdoor bulk cryogenic tank plants that hold oxygen; a set of indoor cylinders that hold a high pressure gas such as for nitrogen or nitrous oxide; or air compressor and vacuum pump plants, each of which has specific redundancy and local alarming requirements. The distribution networks for gas and vacuum systems include piping, valves, gauges, inlets and outlets, zone valve boxes, and area alarm panels. The list also includes specialty devices such as wall-mounted, low-pressure emergency oxygen supply connections, used only when the outdoor bulk cryogenic tank plant is out of product or out of service. The HVAC connection NFPA 99 also plays a role in how environmental HVAC systems are designed for anesthetizing locations. Here, the standard requires the relative humidity of an anesthetizing location to be controlled within the 35% to 55% range in order to avoid hypothermia in patients and to reduce incidents of wound infections. NFPA 99 establishes criteria to reduce fire, explosion and electrical hazards in healthcare facilities, and the standard complements several related NFPA standards. Sustaining healthcare power Chapters 4 through 6 of the standard’s 2005 edition are dedicated to the performance, maintenance, installation, and testing of electrical, gas/vacuum, and environmental systems. Both the normal and essential power systems, including common elements such as circuiting, grounding, circuit protection, and device types within patient care areas, as well as ground fault protection and isolated power systems, are addressed in this section. Defining how essential power sources should be configured and how distribution systems must be arranged, NFPA 99 includes parameters for the following: • What loads can and must be connected to a standby generator Consulting-Specifying Engineer • DECEMBER 2007 49
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