Safely Using Hydrogen In Laboratories

WestAir Specialty Gases and Equipment carries a large selection of hydrogen to Southern California, along with several other specialty gases. WestAir Specialty Gases and Equipment quite often supplies hydrogen and other specialty gases to research laboratories and several other industries, so we felt it would be helpful for our Southern California customers to be updated on the safe use of hydrogen in laboratories.

With increasing costs correlated with the limited volume of available helium, operators and designers of laboratory equipment are progressively turning to their gas suppliers for hydrogen.  Hydrogen is used in a wide array of facilities from analytical laboratories to universities, medical research facilities, and chemical process buildlings.  However, it is imperative to be cautious of the risks that conincide with the storage, distribution, and use of hydrogen along with the fire and safety code regulations created by the National Fire Protection Association’s Compressed Gases and Cryogenic Fluids Code (NFPA 55) and the International Fire Code (IFC) and International Building Code (IBC).

Recent updates to NFPA 55 have altered the Maximum Allowable Quantities (MAQ) spelled out specifically for hydrogen. These MAQ’s are identified for each storage area, affected by storage in either an unsprinklered or completely sprinklered building and limited additionally based on whether the hydrogen cylinders are contained in gas cabinets or other locations. The corresponding volumes are expressed as standard cubic feet (cuft) of hydrogen at 1 atmosphere of pressure. In an unsprinklered building where not all cylinders are stored in gas cabinets, the MAQ is bounded to 1,000 cuft, whereas that quantity is multiplied to 2,000 cuft if all cylinders are stored in gas cabinets. Additionally, for sprinklered rooms in which some cylinders are not stored in gas cabinets, the MAQ is also 2,000 cuft. That number is increased to 4,000 cuft if all cylinders are stored in gas cabinets. NFPA further defines limitations determined by hydrogen use in control areas or using outside storage, part II of this series will explain the infrastructure demands for compliance.

We will continue our discussion by selectively describing some of the primary areas and necessities for hydrogen installation in terms of fire-resistance rating and ventilation.Section 6.3.1.3.1 of NFPA explains that for flammable gases saved or used in greater quanities than 250 cubic feet, a 1-hour fire resistance rated constrction should be employed for separation in the area. The compressed gas cylinders should be separated by 10’ or a fire-resistant wall; but, they need to be separated by 20’ or a nonflammable wall that contains a minimum fire resistance rating of .5 hours from incompatible matters like oxygen. For locations that contain hydrogen systems, necessary safety notices must also be permanently affixed.

Additionally, Section 6.16 describes that storage and use areas that are inside must be given either natural or mechanical ventilation, so long as the natural ventilation is verified to be adequate for the gas employed. If using mechanical ventilation, the system must be operational while the building is occupied, with the rate of ventilation not reaching lower than 1 ft3/min per square foot of floor area of storage/use and being equipped with an emergency power system for alarms, vents, and gas detection. The system is also tasked with accounting for gas density to ensure adequate exhaust ventilation. Part III of this series will expand on the other NFPA 55 requirements for separation and controls.

In continuing the series detailing updates to NFPA 55 governing the safe use of hydrogen in laboratories, we will elaborate on our discussion selectively addressing some of the primary areas and requirements for hydrogen installation in reference to separation and controls.Section 7.1.6.2 of NFPA 55 dictates that any flammable or oxidizing gases need to be separated by 20’ from each other, while section 7.1.6.2.1 dictates that this space can be limitlessly lowered when separated by a barrier made of noncombustible material a minimum of 5’ tall that provides a fire resistance rating of at least .5 hours.

The safe use of controls in hydrogen systems are declared by NFPA 55, IFC, & IBC, creating a slightly more nuanced requirement for compliance. Section 414.4 of the IBC demands that controls must be suitable for the intended application, with automatic controls being required to function without fail. Section 2703.2.2.1 of the IFC calls for suitable materials for hazardous media, the main negative result being that 316L SS or copper piping shall be employed and identified in accordance with ASME A13.1 with directional arrows every 20’. The system should also contain no concealed valves or breakable connections, using welded or copper brazed joints where the piping is concealed. NFPA 55 dictates that these brazing materials should have a melting point above 10,000°F.Aside from piping requirements, these codes also require the use of emergency shutoff valves on supply piping at the point of use and source of compressed gas, along with backflow prevention and flashback arrestors at the point of use.

As the last section in the NFPA 55 series governing the safe use of hydrogen in laboratories, we will conclude our discussion by detailing employments where the Maximum Allowable Quantities (MAQ’s) is less than the demand for hydrogen gas cylinders.

It is not unusual to come across installations where the requirement for hydrogen is larger than the MAQ’s, usually in instrumentation employements and/or chemical reactions like hydrogenation. These are often encountered in installations using hydrogen where outside storage is unavailable and control to line pressures smaller than 150 PSIG is unobtainable . The NFPA 55 code and the IBC and IFC requirements allows these volumes exist within a building; however, certain building improvements are called for, effectively dictating that a hydrogen shelter be built by the facility. These upgrades consist of advancements to the structure fire rating, transportation, fire detection, a limitation on the number of occupants, and a building story limit. Not only this, but these installations likewise have strict requirements in regards to distancing along with floor and wall ratings. While this is possible, this is not the best situation and should be averted when possible. A more efficient resolution would be to group the facility’s requirements into many, smaller systems in which the compressed gas cylinders may be inserted completely in gas cabinets.

WestAir Specialty Gases and Equipment is a reliable132] supplier of hydrogen, along with many other specialty gases and specialty gas equipment to the Southern California area. Whether you are looking for specialty gases for use in your laboratory research, or any other industry in Southern California, WestAir Specialty Gases and Equipment will have the products you need to complete your tasks. To find out more about WestAir Specialty Gases and Equipment and our specialty gas products in Southern California, browse our website and catalog. We can be reached at 866-WESTAIR or via email at info@westairgases.com
 
 
 
Larry Gallagher
CONCOA 
2/10/2016