CGA Helps Ensure 2 National Fire Protection Association Codes (NFPA 99 and NFPA 55) Remain Consistent

January 7, 2021

At the December 2, 2020 meeting of the Standards Council for the National Fire Protection Association (NFPA), the Compressed Gas Association won an appeal requesting that NFPA issue TIA (tentative interim amendment) number 1521 to correct language in NFPA 99, Health Care Facilities Code, which had diverged from the language in NFPA 55, Compressed Gases and Cryogenic Fluids Code. A TIA corrects the language until an NFPA code can be revised during its normal revision cycle.

The language in question provides requirements for medical gas supply systems at health care facilities. Keeping the requirements consistent between these two codes is critical to ensuring that designers of medical gas supply systems find consistent, best-practice requirements in either code.

Additional information about medical gas supply systems may be found in our recent article, CGA’s M-1 Publication Guides Safe Use of Medical Gas Supply Systems at Health Care Facilities, as well as in safety publication CGA M-1, Standard for Medical Gas Supply Systems at Health Care Facilities (an American National Standard).


For many years, requirements for medical gas supply systems were found in three sections of NFPA codes:

  • NFPA 55, chapter 8 – Cryogenic fluids
  • NFPA 55, chapter 9 – Bulk oxygen systems
  • NFPA 99, chapter 5 – Gas and vacuum systems

Members of technical committees for NFPA 55 and NFPA 99 recognized that having scattered requirements could result in users not finding all the requirements, thus resulting in less-than-optimal supply systems. In 2015, members of both technical committees established a joint NFPA 55/99 task group to resolve this issue. CGA Technical Manager and NFPA 55 technical committee Chair Rob Early served as the chair of the task group. Task group members came from both the NFPA 55 technical committee and from the NFPA 99 piping technical committee.

The task group developed and executed a plan to consolidate all the requirements for medical gas supply systems into a new chapter 17 in NFPA 55. To accommodate those users who may wish to purchase only one standard, the task group decided to have NFPA 99 use the NFPA extract policy to copy and paste NFPA 55 chapter 17 material into NFPA 99 chapter 5. A user of NFPA 99 could then access requirements for medical gas supply systems and health care facility piping systems in a single code.

Making this change allows the NFPA 55 technical committee, which has more expertise in supply systems, to maintain these requirements for health care facilities such as hospitals. The plan also allows the NFPA 99 piping technical committee to focus on piping systems within health care facilities.

NFPA 55 2020 edition includes the new chapter 17. The NFPA 99 piping technical committee updated NFPA 99 2021 edition to extract material from NFPA 55 chapter 17.

Why the TIA?

Although the NFPA 99 piping technical committee extracted all of NFPA 55 chapter 17, they made a change that created a conflict between the two codes. NFPA 55 requires a minimum of three feet of clearance around all four sides of the liquid storage tank, the vaporizers, and the front of the pressure regulating manifold/cabinet.

In contrast, the requirement in NFPA 99 was changed to require the clearance around only three sides of the equipment, mainly due to concerns about having sufficient room for the supply systems. Not only did this create a conflict between the two codes, it was not ideal for medical gas supply system performance. The increased use of medical oxygen during the COVID-19 crisis has led to greater icing on vaporizers and piping. For that reason, it is important to have adequate space on all four sides of vaporizers and equipment to allow room for ice to grow.

The TIA was submitted to correct this error.

What Led to the Appeal?

The TIA was not approved by NFPA 99 and an appeal to NFPA’s Standards Council was needed to incorporate the needed change. During the December NFPA Standards Council meeting, Rob Early presented the appeal, and on December 18, 2020, NFPA Standards Council issued their approval of the appeal. TIA 1521 will now be issued, keeping the two codes consistent.

CGA members spend considerable effort on technical committees for NFPA 55, NFPA 99, and other NFPA codes and standards. Having this appeal upheld is a good result for CGA by adding the best language to NFPA 99.