Adjust Oxygen Cylinders to NTP for MAQ Limits?

I’m working on a fire protection assessment for a facility that stores multiple oxygen cylinders, and I need to verify whether the stored quantity exceeds the Maximum Allowable Quantity (MAQ) per control area per the IBC/IFC.

The facility has a mix of oxygen cylinders in different sizes, and I’m trying to determine the correct method to calculate the aggregate oxidizing gas quantity.

My main question is: When calculating total oxygen gas quantity, is it correct to standardize the volume to NTP (Normal Temperature and Pressure) before comparing with IFC/IBC MAQ limits?

Or should the calculation simply use the manufacturer’s stated gas content (e.g., cubic meters or SCF at normal conditions)?

The reason I’m asking is that if I convert pressurized gas to NTP volume, even a single “standard” 40-liter cylinder at 140 bar would exceed the MAQ for oxidizing gases and potentially classify the space as a High-Hazard Occupancy (H-2/H-3).

​I want to confirm whether this interpretation is correct, or if the code expects the use of the manufacturer’s rated gas quantity instead of a full expansion-to-NTP calculation. Thanks in advance.

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