Safely Using Hydrogen In Laboratories

Elite Air carries a large selection of hydrogen to Riverside, along with several other specialty gases. Elite Air frequently supplies hydrogen and other specialty gases to research laboratories and several other industries, so we felt it would be helpful for our Riverside customers to be up to date on the safe use of hydrogen in laboratories.

With increasing costs related to the limited amount of helium that is available, those tasked with operating and designing laboratory equipment are increasingly 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.  Still, it is extremely important to comprehend the risks that hydrogen storage, distribution, and use present along with the fire and safety code requirements controlled 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 redefined the Maximum Allowable Quantities (MAQ) specifically established for hydrogen. These MAQ’s are discerned for each storage area, decided by storage in either an unsprinklered or completely sprinklered building and restricted further based on whether or not the hydrogen cylinders are being contained in gas cabinets. 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 number is multiplied to 2,000 cuft if all cylinders are stored in gas cabinets. Additionally, for sprinklered rooms where not all cylinders are 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 defined by hydrogen use in control areas or utilizing outside storage, part II of this series will explain the infrastructure necessities for compliance.

We will further our discussion by selectively describing some of the principal areas and needs for hydrogen installation when referring to fire-resistance rating and ventilation.Section 6.3.1.3.1 of NFPA explains that for flammable gases saved or employed in amounts greater than 250 cubic feet, a 1-hour fire resistance rated constrction will be utilized to separate the area. The compressed gas cylinders should be separated by 10’ or a nonflammable wall; yet, they must be separated by 20’ or a noncombustible wall having a minimum fire resistance rating of .5 hours from incompatible materials like oxygen. For places having hydrogen systems, proper safety notices must also be permanently affixed.

Likewise, Section 6.16 states that storage and use areas that are inside must be ventilated either mechanically or naturally, 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 being at a minimum of 1 ft3/min per square foot of floor area of storage/use and having an emergency power system for alarms, vents, and gas detection. The system is also tasked with accounting for gas density to guarantee sufficient exhaust ventilation. Part III of this series will elaborate on the rest of the NFPA 55 requirements for separation and controls.

To continue the series that explains updates to NFPA 55 regulating the proper utilization of hydrogen in laboratories, we will elaborate on our discussion selectively addressing some of the main areas and requirements for hydrogen installation in terms of 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 distance can be limitlessly reduced when separated by a barrier constructed 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 stated by NFPA 55, IFC, & IBC, creating a slightly more nuanced neccessity for compliance. Section 414.4 of the IBC demands that controls must be suitable for the intended application, with automatic controls being required to operate fail-safe. Section 2703.2.2.1 of the IFC requires suitable materials for hazardous media, the main negative result being that 316L SS or copper piping shall be utilized 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 utilization 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 final installment in the NFPA 55 series that details the the proper use of hydrogen in labs, we will finish our analysis by detailing employments where the need for hydrogen gas cylinders is higher than the Maximum Allowable Quantities (MAQ’s).

It is common to find installations where the demand for hydrogen is greater than the MAQ’s, frequently in instrumentation employements and/or chemical reactions like hydrogenation. These are frequently come across in installations using hydrogen where there is no outside storage available and control to line pressures of less than 150 PSIG is unobtainable . The NFPA 55 code in addition to the IBC and IFC requirements will allow for these volumes exist within a building; however, certain building improvements are needed, effectively dictating that the facility build a hydrogen shelter. These upgrades are comprised of advancements to the structure fire rating, transportation, fire detection, a limitation on the number of occupants, and a limit to the number of stories a building can have. 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 combine the facility’s requirements into many, smaller systems within which the compressed gas cylinders can be installed exclusively in gas cabinets.

Elite Air is a reliable132] supplier of hydrogen, along with many other specialty gases and specialty gas equipment to the Riverside area. Whether you need specialty gases for use in your laboratory research, or any other industry in Riverside, Elite Air will have the products you need to carry our your operations. To find out more about Elite Air and our specialty gas products in Riverside, browse our website and catalog. We can be reached at (951) 686-7822 or via email at info@cal-tool.com
 
 
 
Larry Gallagher
CONCOA 
2/10/2016