Gas Storage Ventilation

Q: In the 1999 Edition of NFPA 99, it mentions for medical gas storage systems more than 3,000 cubic feet, if the door opens to an exit access corridor, louvered openings shall not be used and a mechanical ventilation system shall be required. I cannot find that requirement in the 2012 edition of NFPA 99 regarding not using a louvered door in an exit access corridors. Has it been eliminated, or am I just missing it? If it was eliminated, do you know why?

A: In a way they eliminated it and in another way they did not. Yes, they did delete the language that says doors that open onto an exit access corridor cannot have louvers for ventilation. But that does not mean you can now have louvers in doors to exit access corridors. Section of the 2012 NFPA 99 is the section for central storage in quantities greater than 3,000 cubic feet of compressed medical gas, and for gas manifold systems.

You will notice that ventilation requirements are no longer under section You will find ventilation requirements for medical gas storage under section 9.3.7, and specifically section describes natural ventilation which now limits the ventilation openings to be directly to the outside atmosphere without ductwork. This precludes the possibility of louvers in a door to an exit access corridor.

And, NFPA 99 requires a fire-rated door for medical gas storage rooms and gas manifold rooms. Louvers are not permitted in fire-rated doors.

There is still an option of using natural ventilation or mechanical ventilation, and plenty of rules for both.

Endoscopy Ventilation Requirements

Q: What are the ventilation requirements for the scope room in endoscopy? This is the room where the clean instrumentation is kept.

A: It all depends if you’re talking about existing conditions or new construction. If you’re talking about existing conditions, then you need to find out what regulations and standards were in effect when the unit was designed. Once the room is constructed to a particular set of ventilation requirements, then they stay that way until you renovate the unit. In other words, you do not have to meet new construction requirements.

If you are talking about new construction requirements, then the 2014 FGI guidelines have the following requirements:


  Air Pressure Relationship Surrounding Areas Minimum Outdoor ACH Minimum Total ACH Room Air Exhausted to Outdoors? Room Unit Recirculation? Relative Humidity Design Temperature Design
Clean Workroom Positive 2 4 NR No Max 60 72-78
Sterile Storage Positive 2 4 NR NR Max 60 72-78
Endoscopy Procedure Room NR 2 6 NR No 20-60 68-73

NR = No Requirement

ACH = Air Changes Per Hour

These are only guidelines. You need to find out if your state or local authorities have more restrictive requirements.

Bronchoscopy Procedure Rooms

Q: Are Bronchoscopy procedures to be performed in negative pressure rooms under all circumstances, or can they be performed in OR suites? Does the negative pressure rule only apply to new construction, or does it apply universally to all facilities old and new?

A: According to the 2010 FGI Guidelines for Design and Construction of Health Care Facilities, ventilation requirements for a Bronchoscopy procedure room requires negative air pressure relationship to the surrounding area, and a minimum of 2 outdoor air exchanges per hour and a total of 12 air exchanges per hour. This ventilation requirement must be met regardless where the Bronchoscopy procedure is conducted, which includes the operating rooms. So, to answer your first question: Yes, this requirement applies to all circumstances.

The ventilation requirements found in the 2010 FGI guidelines applies to new construction or renovated areas. It is not a standard, and it does not apply to existing conditions. However, the ventilation requirements for Bronchoscopy procedures have been consistent since the 1996-1997 edition of the guidelines, and perhaps even before that (I only have records back to the 1996-1997 edition). So, if you have constructed or renovated the Bronchoscopy procedure room since 1996-1997, then these ventilation requirements must be complied with.

Some authorities will allow deviance from the FGI guidelines as they are guidelines and not standards. So, if you have extenuating circumstances that requires you to deviate from the FGI guidelines, then contact your AHJ to determine what their expectations are.

Frequency of Ventilation Checks

Q: Is there a code or standard that states how frequent the test intervals must be for air-exchange rates and air-pressure relationships in operating rooms, soiled utility rooms, and central sterile supply clean rooms must be conducted? We check air-pressure relationships periodically, but typically we only check air-exchange rates if we suspect or know of a problem.

A: Depending on the particular authority having jurisdiction (AHJ), they may have specific standards that addresses the frequency of air-pressure checks and air-exchange rates, but generally speaking, there is no specific code or standard that addresses this on a national level, that I am aware of. A quick check of the FGI Guidelines (2010 edition) did not identify anything specific on the frequencies of these checks. NFPA, CMS, Joint Commission, HFAP and DNV do not have specific standards that address the frequency of ventilation checks.

When the standards do not specifically state a specific action, then it is up to the AHJ to make an interpretation on this issue. Where the AHJ has not made an interpretation, then it is up to the institution to make an interpretation. But be aware, that most AHJs have their own interpretation and/or rules on the frequency of air-pressure checks and air-exchange rates, whether they publish those interpretations or not. Many of them usually want to see daily checks on basic requirements like air-pressure relationships to surrounding areas. This can be done with a tissue held at the bottom of the door to confirm air-flow in or out of the room; or you can invest into some air-pressure gauges that are mounted on the wall. The air-exchange rates are more difficult to confirm, so this may be done less frequent, such as semi-annual or annual. Check with your operating room nurse manager. I believe their professional organization, the Association of periOperative Registered Nurses (AORN), has published recommendations of daily checks for air-pressure relationship requirements for operating rooms. Make sure all checks are documented.

My best advice for you is to contact all of your AHJs and ask them directly how frequent they expect you to test these ventilation requirements.

FGI Standards on Ventilation

Q: The Centers for Medicare & Medicaid Services (CMS) standard §482.41(c)(4) states in their Interpretative Guidelines that hospitals must comply with the Facilities Guidelines Institute (FGI) for ventilation in anesthetizing locations. The Joint Commission standard EC.02.06.05, EP 1 requires compliance with the same FGI standards on ventilation. Our operating rooms were designed more than 20 years ago when the AIA guidelines at the time had less air changes per hour than what the new 2010 FGI guidelines require. Am I supposed to modify my current ventilation equipment in order to comply with the new 2010 FGI guidelines for air changes per hour? 

A: This short answer is No; you do not have to modify your existing air handler to meet the new 2010 FGI guidelines on air changes per hour, unless you alter, renovate or remodel the rooms the ventilation equipment serves. The Interpretative Guidelines for the CMS standards are not part of the enforceable standards, and are considered references. CMS does not expect compliance with the new FGI guidelines on existing equipment; only on new construction. Also, CMS states “acceptable standards such as from the Association of Operating Room Nurses (AORN) or the FGI should be incorporated into hospital policy.” This means, the FGI guidelines are not the only standard you should consider when designing new construction or renovated areas.

In regards to the Joint Commission standard EC.02.06.05, EP 1, it clearly states in the standard: “When planning for new, altered, or renovated space…” This means the FGI guidelines only apply to new construction, and not to existing conditions. And the FGI guidelines are only one of a set of criteria that the organizations may choose to comply with. The others are state rules and regulations or other reputable standards and guidelines that provide equivalent design criteria.

CMS Requirements on Ventilation Testing

Q: What does CMS require as far as frequency of testing of air changes per hour (ACH) in hospitals? I see where we are supposed to test and know what ACH is required, but I have not seen at what frequency we are to test. 

A: You raise a very interesting point. CMS seems to have a different philosophy when it comes to writing standards, than say, The Joint Commission, HFAP or DNV. CMS does not write into their standards as much detail or specifics as the accreditors do. CMS does rely heavily on their written Interpretive Guidelines and Survey Procedures that they include with their standards. At times, these Interpretive Guidelines and Survey Procedures have very useful and detailed information.

In regards to ventilation requirements, CMS standard §482.41(c)(4) says “There must be proper ventilation, light, and temperature controls in pharmaceutical, food preparation, and other appropriate areas”. That’s all it says in the standard, which is not much to go on. But their Interpretive Guidelines for this standard says: Acceptable standards such as from the Association of Operating Room Nurses (AORN) or the Facilities Guidelines Institute (FGI) should be incorporated into hospital policy.”

So, CMS is saying in their Interpretive Guidelines that the FGI Guidelines must be followed for ventilation requirements. But it is important to understand that the FGI Guidelines are not retroactive to existing conditions, but are used for the design of new construction or renovated areas. For existing conditions, you need to be compliant with the laws, regulations and FGI Guidelines (or AIA Guidelines, if the area is that old) that were in affect at the time the area was designed or renovated.

If your existing area can meet the current FGI Guidelines, then that is great and you’re in good shape. If your existing area cannot meet the current FGI Guidelines, then you need to determine what regulations or guidelines were in effect at the time the area was constructed. If you meet those ventilation requirements, and you can document that, then you’re in good shape.

Now, to answer your direct question: “What does CMS require as far as frequency of testing of air changes per hour (ACH) in hospitals?” The answer is…CMS does not specify how frequent you need to check the ACH rates, and neither does the FGI Guidelines appear to specify how frequently you need to check your ACH rates. But that does not mean you do not have to perform periodic checks. The answer is… You get to decide how often you check the ACH rates, but it better be based on reasonable assumptions. The state agency surveyors who will survey your hospital on behalf of CMS will have expectations on how often you check the ACH. I could offer suggestions, but ultimately you need to know and follow what your state agency inspectors expect. I suggest you contact them and discuss this issue with them to understand what their expectation will be.

Plenum Rated Cable

Q: We have decorative wood panels in our cafeteria ceiling which do not provide a seal to limit the passage of smoke. In fact, there are wide gaps between the wood panels. HVAC supply ductwork is mounted above the wood panels and return air is drawn through the open space above the wood panels as well. Are we required to use plenum rated cabling above the wood panels?

A:  The Life Safety Code, 2000 edition, section 3.3.150 defines a plenum as a compartment or chamber to which one or more air ducts are connected and that forms part of the air distribution system.Given that the above-ceiling space is used as a chamber for the return air of the HVAC system, the space appears to be a plenum and I would conclude that plenum-rated cable should be used. NFPA 70 (1999 edition), section 300-22(b) specifies that Type MI or Type MC cable must be installed in ventilating air plenums. This standard does allow limited lengths of flexible metal conduit and liquid-tight flexible conduit to devices permitted to be in the plenum.

Ventilation Requirements for Endoscopy Procedure Rooms

I was asked recently if the ventilation requirements for Endoscopy procedure rooms have changed recently, and the answer is yes. But the changes only apply to new construction, meaning you are not required to go back and retroactively update the ventilation design of the Endoscopy rooms.

The following editions of the Guidelines for Design and Construction of Healthcare Facilities have the following air pressure relationship requirements:



  • (AIA) 1996-1997 edition                 Neutral                 6 ACH                    2 ACH (outdoor air)
  • (AIA) 2001 edition                           Negative               6 ACH                    2 ACH (outdoor air)
  • (FGI) 2006 edition                           Neutral                 6 ACH                    2 ACH (outdoor air)
  • (FGI) 2010 edition                           Positive               15 ACH                     2 ACH (outdoor air)

So, from 1996 to 2010, the air pressure relationship for the endoscopy procedure room, went from being neutral, to negative, back to neutral, then to positive, and the air changes per hour (ACH) went from 6 to 15.

These are guidelines, and are not standards, meaning these are meant to be followed at the time of new construction, unless there are other reasons not to follow them (such as state requirements). The good thing is, as long as you have documented what edition of the guidelines you designed your Endoscopy procedure room to, you are not required to go back and update the room to meet the newer edition of the guidelines.

Typically, most states have firm requirements on ventilation requirements in hospitals that frequently follow along with the guidelines, so in those situations the hospital would have to follow the state’s requirements. Joint Commission has currently adopted the 2010 FGI guidelines (see EC.02.05.01, EP 6) which applies to new construction, and is not enforceable to older designs (many surveyors are not fully aware of this). Again, the guidelines are just guidelines, not standards. In lieu of any other reason, TJC would expect compliance with the guidelines that apply at the time the Endoscopy room was constructed.

CMS has not adopted any specific edition of the Guidelines…. See §482.41(c)(4) [A-0726], which requires ‘proper ventilation’. The CMS interpretative guidelines for this standard just says acceptable standards from AIA should be incorporated. This is not a specific requirement to use the AIA (or FGI) Guidelines. [NOTE: AIA used to write the Guidelines for Design and Construction, but in 2006 they turned it over to FGI.]

Ventilation Requirements in Laboratories

Q: Is there a Life Safety Code regulation stating the need for 100% outside air for the lab HVAC system or where could I find the requirements that regulate this issue?

A: There is not a specific regulation for 100% outside air for the Lab HVAC system that I am aware of, but there is plenty written about it proper ventilation in the lab. Section of the 2000 edition of the Life Safety Code (LSC) requires compliance with NFPA 99 (1999 edition) Health Care Facilities. Section 10-3.4 of NFPA 99 refers to section 5-4.2 of the same standard, which requires a balance of fresh air when exhaust systems are used to produce a slight negative in the lab.  Section 10-3.4 also refers you to NFPA 45 (1996 edition) Standard on Fire Protection for Laboratories Using Chemicals where section 6-2.1 states ventilation systems shall be designed to ensure that chemical fumes originating from the laboratory operations shall not be re-circulated. So, while there is no direct requirement for 100% outside air for HVAC ventilation, I have seen some labs constructed this way to ensure that no chemical fumes are re-circulated into the HVAC air stream. However, you can use an exhaust system in the area where flammable chemical fumes are used to prevent the air from re-circulating as well, and then allow some of the HVAC ventilation air to re-circulate. Also, section 6-3.3 of NFPA 45 requires the air pressure in the lab to be negative in respect to corridors and non-laboratory areas.

Additional places to look for regulations or guidelines on this would be:

  • The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standards may provide guidelines on air exchanges or ventilation requirements
  • State licensing requirements- Check with your state department of public health
  • College of American Pathologists (CAP) regulations