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Medical Liquid Oxygen Oxidizer Class

wmott

SAWHORSE
Joined
Jun 24, 2019
Messages
21
Location
Massachusetts
I have been searching all over the web for the oxidizer class for O2 tanks in a veterinary clinic with no luck.

Anyone know if it is a class 1, 2, 3, or 4?

THANKS
 
Well, the IFC provides definition of the oxidizer classifications as follows:

OXIDIZER. A material that readily yields oxygen or other oxidizing gas, or that readily reacts to promote or initiate combustion of combustible materials and, if heated or contaminated, can result in vigorous self-sustained decomposition.
Class 4. An oxidizer that can undergo an explosive reaction due to contamination or exposure to thermal or physical shock and that causes a severe increase in the burning rate of combustible materials with which it comes into contact. Additionally, the oxidizer causes a severe increase in the burning rate and can cause spontaneous ignition of combustibles.
Class 3. An oxidizer that causes a severe increase in the burning rate of combustible materials with which it comes in contact.
Class 2. An oxidizer that will cause a moderate increase in the burning rate of combustible materials with which it comes in contact.
Class 1. An oxidizer that does not moderately increase the burning rate of combustible materials.

Not an expert, but oxygen (O2) would seem to fall under Class 4, maybe Class 3. For sure no lower than that though.
 
5306.1 General.
Medical gases at health care-related facilities intended for patient or veterinary care shall comply with Sections 5306.2 through 5306.5 in addition to other requirements of this chapter and Section 427 of the International Building Code.
 
It is none of those classes if it is in gas form (or even liquid form, as I explain later).

IFC Tables 5003.1.1(1) and 5003.1.1(3), and IBC Table 307.1(1), under the "Storage" and "Use-Closed System" columns, state "NA" for gases when using the Oxidizer Class 1, 2, 3, and 4 rows. That is because the four classes pertain only to liquids and solids.

What is interesting is that IFC Appendix E (Sections E102.1.2 and E102.1.7), does include oxygen in both the compressed gas oxidizing category and the gas oxidizer category. However, in liquid form, oxygen is not included in any of the examples provided by IFC Section E102.1.7.1 for any of the four classes for oxidizers. My guess is that oxygen must be compressed at 49.2 atmospheres at -183 deg. Celsius to remain in liquid form. At that point, it is really a cryogenic oxidizer, which is included in another category per the two tables.

If in a compressed gas form, then it is classified as an "oxidizing gas" and not an "oxidizer." The link below is to the SDS for compressed oxygen by Airgas--a company that I think knows a little about O2:


Edit: Here is the SDS for the liquid form:

 
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