Level 3 Medical Gas (Oxygen and Nitrous Oxide) Line Sizing

NFPA 99 defines the medical gas systems for all healthcare facilities based on a number of factors all related to the safety of the patients who are connected to them. Each medical gas “system” from the source equipment to the outlet/inlet termination point can be placed into one of three categories or “levels”. The least stringent requirements are applicable to Level 3 facilities which are typically (but not necessarily always) dental facilities.

One of the requirements for the oxygen and nitrous oxide piping systems for Level 3 facilities is that the line sizes for each of these gases be different so as to clearly distinguish separation of the piping systems as they are routed throughout the facility. Para. of the 2005 edition of NFPA 99 dictates a minimum line size of (NPS 3/8” or ½” OD) for oxygen systems and (NPS ¼” or 3/8” OD) for nitrous oxide systems. The intent of this distinction is to prevent cross connection of these two gases as explained in Para. A. Most of these source systems (manifolds) are manufactured as a common enclosure for both gases, with two copper feed lines extending out from the top of the enclosure. Sometimes these feed lines are the same line size, which can be confusing, especially if these lines are not correctly labeled.

Recently, (March 2009) a terrible accident occurred in Togonoxie, KS when a patient in a dental office was given nitrous oxide gas instead of oxygen, as a practitioner intended. According to news reports, this mistake was due to the “incorrect connection of the medical gas lines.” The full article on this medical gas mishap can be viewed at: http://www2.ljworld.com/news/2009/apr/22/medical-gas-accident-may-lead-policy-change/

Medical Gas Brazing Continuity

Brazing Continuity

Once an individual has passed an ASSE 6010 Installer course they are required to submit a brazing continuity affidavit, stating that they have successfully brazed using the proper procedure. This is done on a 6 month basis. At EMGS, Inc. we mail continuity forms to all of our installers and require them to sign and return them for verification of this requirement. The code reference for this requirement is below:

The 2005 edition of NFPA 99 in paragraph states:

“Performance qualification of brazers shall remain in effect indefinitely unless the brazer does not braze with the qualified procedure for a period exceeding 6 months; or there is a specific reason to question the ability of the brazer.”

If you hold an Installer license, it is very important that you adhere to this so there is no lapse in the validity of your license. Please check periodically with your certifying agency for requirements and examine your brazing license to be sure all expiration dates are valid.

Medical Gas Licensing – State Legislature Requirements

Most of the states in the U.S. have passed legislation requiring individuals that install medical gas systems to have an ASSE 6010 credential. This type of credential (and course) is relatively familiar to most parties involved in the design, installation, verification, and maintenance of these systems; however, the ASSE 6000 standard published in 2006 actually contains a total of eight discipline compliance standards, which are as follows:

ASSE 6005 – General Information (usually applicable to engineers)

ASSE 6010 – Medical Gas Systems Installers

ASSE 6015 – Bulk Systems Installers

ASSE 6020 – Medical Gas Systems Inspectors

ASSE 6030 – Medical Gas Verifiers

ASSE 6040 – Maintenance Personnel

ASSE 6050 – Medical Gas Systems Instructors

ASSE 6055 – Bulk Systems Instructors

Some states are now contemplating the passage of legislation which would require credentialing to the “ASSE 6040 Maintenance Personnel” standard for all individuals who are involved in the “repair and maintenance” of medical gas systems. Also under consideration is the credentialing of municipal inspectors to the ASSE 6020 “Medical Gas Systems Inspectors” standard. Compliance with these standards will help to ensure that procedures, decisions, and documentation regarding medical gas systems are performed by individuals with the knowledge base to do so. All trades involved in these practices need to be aware of their state’s current legislative requirements.

Please visit the following links for two examples of states that are making legislative changes regarding medical gas licensing.



ASSE 6000 Medical Gas Training

Training to Fit Your Company’s Needs

EMGS, Inc. offers medical gas training courses that can benefit plumbing companies, individual contractors, engineering firms, and hospital personnel. We can customize a training package to fit your needs and can travel to you for convenience.

Review our course listing here and then contact us to discuss the training package that’s right for you.