How to use NFPA 99

There are many changes to NFPA 99-2012. Engineers should review the code carefully to better understand how it affects electrical systems, risk assessments, and other pertinent topics.


Do the recent changes in NFPA 99: Health Care Facilities Code require isolation panels in all operating rooms?

NFPA 99-2012 has so many changes throughout the document that the committee decided to forgo the usual markers that indicate a change. Several of the code changes are relocated sections to improve organization. However, there is an obvious philosophical shift within the code.

This shift is apparent within the new text of Chapter 4 (formerly Electrical Systems). It’s apparent that risk assessment procedures are going to play a more formal role in certain code interpretations. Unfortunately, when someone asks you, “Does that meet code?” the technically correct answer is going to be “It depends on the risk assessment.”

So what does risk assessment/risk probability all mean?

NFPA 99 doesn’t give a lot of firsthand guidance on a “defined risk assessment procedure” other than giving the four categories of risk (NFPA 99-2012 Section 4.1) and a reference to ISO/IEC 31010, NFPA 551: Guide for the Evaluation of Fire Risk Assessments, and SEMI S10-0307E. These documents contain some new concepts for the design engineer to consider, which are strongly encouraged for reading.

For some reason, the average person tends to think of risk probability in terms of his or her chance of getting hit by lightning (1 in 700,000 per year, or 0.000001% chance of being hit). Even though it’s not the engineer’s role to interpret or conclude for a facility what an “acceptable” risk level is, it’s always useful to have a reference benchmark when asked “What does that mean?”

Chapter 6 is now dedicated to Electrical Systems; it’s nearly a duplicate of NFPA 99-2005 Chapter 4. However, NFPA 99-2012 Section now states, “Operating rooms shall be considered to be a wet procedure location, unless a risk assessment conducted by the health care governing body determines otherwise.”

The appendix A. also states, “In conducting a risk assessment, the health care governing body should consult with all relevant parties, including, but not limited to, clinicians, biomedical engineering staff, and facility safety engineering staff.”

Depending on your personal bias, this is clear and conclusive proof that:

  1. All new operating rooms should be considered wet locations and as such should be equipped with an isolated power system, OR
  2. Isolated power systems are not required in any new operating rooms, as long as the facility performs a risk assessment and that the risk is relatively low.

Engineers typically stick to the facts, but it’s worth stressing that there is a great deal of debate about this change in the code.

What is a wet location?

The American Society for Healthcare Engineering (ASHE) has come out with a statement clearly articulating its objection to classifying all operating rooms as wet locations (see their white paper titled, “NFPA 99: How to Conduct Operating Room Risk Assessments”). ASHE relates the ongoing struggle on this issue back to 1970 and articulates a general methodology for conducting a risk assessment based on empirical measurements of existing operating rooms. Unfortunately, most engineers do not have access to an existing operating room for empirical testing. If you have a fully engaged owner/client, this is a good document to read.

There is also a well-written article issued by the Fire Protection Research Foundation, “Operating Rooms as Wet/Dry Locations Risk Assessment Project” (Brenton Cox, PhD, Exponent Inc., 2012). The article does a good job of identifying a mathematical model for the general terms outlined in NFPA 99.

Since most consultants are conservative and risk averse, the majority will gravitate toward conclusion Number 1 described above. However, like all things in our profession, it’s not going to be that simple. As clients become more cognizant of this issue, they will start asking, “Do I really need isolated power in all of my operating rooms?” or “I spoke with my colleague and he doesn’t have isolation panels, why do I need them?” or “Can you perform a risk assessment for me?”

Because I’ve been down this road, I’m going to share with you what I’ve learned and how you can use it with your clients.

<< First < Previous 1 2 Next > Last >>

Juan , Non-US/Not Applicable, Peru, 06/19/14 08:50 PM:

Consulting-Specifying Engineer's Product of the Year (POY) contest is the premier award for new products in the HVAC, fire, electrical, and...
Consulting-Specifying Engineer magazine is dedicated to encouraging and recognizing the most talented young individuals...
The MEP Giants program lists the top mechanical, electrical, plumbing, and fire protection engineering firms in the United States.
integrated building networks, NFPA 99, recover waste heat, chilled water systems, Internet of Things, BAS controls
40 Under 40; Performance-based design; Clean agent fire suppression; NFPA 92; Future of commissioning; Successful project management principles
BIM coordination; MEP projects; NFPA 13; Data center Q&A; Networked lighting controls; 2017 Product of the Year finalists
Transformers; Electrical system design; Selecting and sizing transformers; Grounded and ungrounded system design, Paralleling generator systems
Commissioning electrical systems; Designing emergency and standby generator systems; VFDs in high-performance buildings
Tying a microgrid to the smart grid; Paralleling generator systems; Previewing NEC 2017 changes
As brand protection manager for Eaton’s Electrical Sector, Tom Grace oversees counterfeit awareness...
Amara Rozgus is chief editor and content manager of Consulting-Specifier Engineer magazine.
IEEE power industry experts bring their combined experience in the electrical power industry...
Michael Heinsdorf, P.E., LEED AP, CDT is an Engineering Specification Writer at ARCOM MasterSpec.
Automation Engineer; Wood Group
System Integrator; Cross Integrated Systems Group
Fire & Life Safety Engineer; Technip USA Inc.
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
click me