Two current (2003) model codes still require enclosed systems and scrubbers as a containment method. Exceptions that allowed the use of CI Emergency Kits are still allowable. However, the two 2003 Fire Code models have undergone new revisions that are as follows:
IFC – The 2003 IFC provides an exception to the use of containment systems when gas detectors and automatic valve operators (shut off systems) are provided. The following is an abstract from the current IFC 2003 statements regarding the use of automatic valve closing devices.
From Treatment Systems – 3704.2.2.7 – exceptions to the requirement for a scrubber are allowed in storage or use areas for toxic and highly toxic gases where (there is):
- A gas detection system with a sensing interval not exceeding 5 minutes.
- An approved automatic-closing fail-safe located immediately adjacent to cylinder valves.
- Treatment systems are not required for toxic gases supplied by portable tanks not exceeding 660 gallons. (Equivalent to 6600 lbs.)
Comments: The 2003 IFC allows the storage and use of 150 pound cylinders and ton containers without the requirement of scrubbers or other containment systems when an automatic, fail-safe shut off valve is employed in the facility at the tank valve.
Note: The reader is urged to obtain a copy of the current IFC code.
UFC – The 2003 UFC allows the use of toxic or highly toxic gases where treatment systems (scrubbers) or containment systems are provided. However, an exception to the use of these systems when gas detectors and automatic shut off valves are provided. The following is an abstract from the current UFC 2003 statements regarding the use of automatic valve closing devices.
From Treatment Systems – 63.3.8.3.2 – exceptions are provided when (there is):
- A gas detection system with a sensing interval not exceeding 5 minutes.
- An approved automatic-closing fail-safe located immediately adjacent to active container, cylinder or tank valves.
- There is no limit neither provided nor mentioned about the size of the gas container.