In Savvy #3 we discussed how the “Category” of a Patient Care Space is determined. This raises quite a few questions, some of which are:

Doesn’t the building itself have a Category? 

NO. However, this was how Categories (back then “Levels”) were originally cast (see the 1996 edition).  Then. the building itself had a Level.  The default was always Level 1 and there was a decision tree that you used to determine if you could qualify to install medical gas systems of another Level.  “Levels” transitioned to “Categories” and also became applicable to systems other than medical gases when the Fundamentals chapter  (99 Chapter 4) was introduced in 2012.  At the same time a transition from Category by building to Category by Patient Care Space began.  That transition occurred gradually and as a result can be confusing, particularly since the Category by Building mental model still echoes in the code.  Nevertheless, all Category designations are now formally assessed by Patient Care Space under Chapter 4 and 99 24 5.1.1.6 is a bridge between the two ways of thinking.  

So Category 1, 2 and 3 patient care spaces can be all hugger mugger throughout the building? 

YES.  And if the risk assessment is being done well, they will be. 

Can general anesthesia and deep sedation be performed in Category 2 or 3 patient care spaces? 

The answer depends on the year of the standard (it’s one of the examples where the Code has become more relaxed over time) 

• Under 2021 and before: NO.  These activities are restricted to Category 1 spaces (see 99 21 5.1.1.2).

• Under 2024: YES, but...  The language advising these activities be limited to Category 1 spaces is moved to the Annex (99 24 A.5.1.1.1).  Annexes are not enforceable, but this hopefully would be considered in the risk assessment. 

• Under 2027: YES.  The advisory language is gone entirely. The Governing Body must understand and assess the risk on their own.  If they do this appropriately they are very probably going with Category 1 in any anesthetizing location, but it is not mandatory and not guaranteed. 

In Chapter 4, the test for categories is “likely to cause” This whole “likely” wheeze - aren’t the medicos always going to answer “not likely” because they would take action to prevent patient injury or death?

Ah, therein lies the discomfort many of us feel about that whole process.  

A risk assessment, properly conducted, is an iterative process.  Initially, one ignores extraordinary actions that might be taken and considers only the unfiltered risk (you can see that reflected in 99 24 A.4.1).  An assessment of likelihood and severity are made without consideration of actions that might be taken.  Then, in the first iteration of the process, actions to mitigate that unfiltered risk are considered, and the likelihood and severity are reassessed in light of those actions.  If the risk is still considered too severe (the ‘appetite for risk’ comes in here) then more actions or different actions  are considered, and another iteration is executed.  One of those actions naturally might  be to assign a more restrictive Category - but that requires we appreciate what that means (i.e. we must understand the code).

Done well, and with the right experts on hand, the risk analysis process should reach a satisfactory conclusion, but it’s not straightforward.  

Are all systems (med gas, electrical, telecommunications, etc.) required to be the same Category?

NO. Remember, the risk is assessed for each specific activity, system and equipment in that specific space. Thus, in a given patient care space, one could theoretically see Category 1 medical gases, Category 3 Telecoms, Category 2 Electrical, etc.  

I’m doing work in a dental facility.  Does this apply to me?

Yep.  Dental (99 Chapter 15) also has categories.  The categories in C15 are more fundamentally based on level of anesthesia than Chapter 5 systems, but the same basic idea of risk assessment to determine Category following Chapter 4 applies.  You will find this in Chapter 14 for medical gases in hyperbaric systems as well.   

How about Hyperbaric facilities?

Yes. The hyperbaric chapter (NFPA Chapter 14) does have categories just like other chapters.  However there isn’t much difference in the medical gas rules between them.  However, if you are working with a hyperbaric facility, you do need to pay attention. 

Why does this matter and where do I find the allowances for the different categories of system?

There are three places where the category is going to make a significant difference in the design process:
• the placement of zone valves;
• the placement of alarms;
• the selection of source equipment.

  Notionally, you are going to find all Category 1 to be under 5.1, Category 2 to be under 5.2 and Category 3 to be under 5.3.  However, in actuality you will find 5.2 and 5.3 usually refer you right back to the relevant part of 5.1. The place where they will be different is with source equipment.  There, you will find:

Category 2 and 3 permit a central supply system for medical air without redundancy.  They can be composed of only one supply source.  In Category 3, they may be with provided only one set of items in the final line regulator assembly.   

Category 2 and 3 permit a central supply system for vacuum without redundancy. 

Category 2 and 3 permit a central supply system for WAGD without redundancy. 

Category 2 and 3 permit a central supply system for instrument air without redundancy.  This includes permission to use a single compressor or a single header (i.e. not a full manifold) as a central supply system.  Any of these may be provided with only one set of items in the final line regulator assembly.

Category 3 systems using oxygen concentrators can be a concentrator supply source with no reserve cylinder header. 

Category 3 systems for other packaged gases may use a single header and not a full manifold as a central supply system, provided with only one set of items in the final line regulator assembly.  The minimum of two cylinders rule is removed, so the source could be no more than a single cylinder or container.

Category 2 and Category 3 systems may have only one alarm, which must include both area alarm and master alarm functions (i.e. a “combination” alarm panel).  It must  be placed in an area of “continuous observation when the facility is in operation” (the assumption being that such facilities are not 24/7 operations).

Category 2 and Category 3 facilities must have an emergency plan for loss of their medical gases when they take advantage of these allowances.  In practice, this should be no different from any category systems, because RFA’s are mandated to manage emergency planning for medical gases to comply with NFPA’s Chapter 12 Emergency Management, and Category 2 and Category 3 facilities must have RFA’s too. 

That said, this may be highly problematic in practice, unless the Category 2 or 3 facility is part of a larger healthcare system and that person is provided by the system.  In small standalone facilities this person is unlikely to exist at all or it may be the facility’s general manager, who can hardly be expected to be very expert on medical gases.