Safely Using Hydrogen In Laboratories

Cryo-Source offers a large selection of hydrogen to Portland, along with several other specialty gases. Cryo-Source quite often supplies hydrogen and other specialty gases to research laboratories and many other industries, so we felt it would be useful for our Portland customers to be knowledgable on the safe use of hydrogen in laboratories.

With escalating costs associated with the limited volume of available helium, those tasked with operating and designing laboratory equipment are progressively turning to their gas suppliers for hydrogen.  The use of hydrogen is found in several facilities, from medical research facilities to universities, analytical laboratories, and chemical process buildings.  Nonetheless, it is imperative to be aware of the risks that hydrogen storage, distribution, and use present along with the fire and safety code rules 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) expressly created for hydrogen. These MAQ’s are discerned for each storage area, affected by storage in either an unsprinklered or fully sprinklered building and restricted further based on the hydrogen cylinders being contained in gas cabinets or not. 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 increased to 2,000 cuft if all cylinders are stored in gas cabinets. Additionally, for sprinklered units where not all cylinders are stored in gas cabinets, the MAQ is also 2,000 cuft. That volume is doubled to 4,000 cuft if all cylinders are stored in gas cabinets. NFPA further defines limitations based on hydrogen use in control areas or employing outside storage, part II of this series will discuss the infrastructure demands for compliance.

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

Additionally, Section 6.16 describes that indoor storage and use areas must be ventilated either mechanically or naturally, so long as the natural ventilation is proven to be acceptable for the gas used. If using a mechanical ventilation process, the system must operate 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 having an emergency power system for alarms, vents, and gas detection. The system must also account for gas density to ensure adequate exhaust ventilation. Part III of this series will detail the other NFPA 55 requirements for separation and controls.

In continuing the series detailing updates to NFPA 55 regulating the proper utilization of hydrogen in laboratories, we will elaborate on our discussion selectively explaining some of the important areas and requirements for hydrogen installation in reference to separation and controls.Section 7.1.6.2 of NFPA 55 explains that any flammable or oxidizing gases must be separated by 20’ from each other, while section 7.1.6.2.1 states that this space can be limitlessly lowered when separated by a barrier comprised 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 need for compliance. Section 414.4 of the IBC demands that controls must be sufficient for the intended application, with automatic controls being required to function without fail. Section 2703.2.2.1 of the IFC demands suitable materials for hazardous media, the main ramification 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 demands that these brazing materials should have a melting point higher than 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 that details the hydrogen’s correct use within laboratories, we will finish our analysis by explaining uses where the need for hydrogen gas cylinders is higher than the Maximum Allowable Quantities (MAQ’s).

It is quite typical to encounter installations in which the need for hydrogen is bigger than the MAQ’s, typically in instrumentation applications and/or chemical reactions like hydrogenation. These are often encountered in installations using hydrogen where there is no outside storage available and control to line pressures lower than 150 PSIG is unobtainable . The NFPA 55 code along with the IBC and IFC requirements allows these volumes be in a building; however, certain building improvements are called for, effectively requiring that the facility constructs a hydrogen shelter. These upgrades are comprised of enhancements 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. These installations also have strict distancing requirements and floor and wall ratings as well. While this is possible, this is not the best situation and should be averted when possible. A better answer would be to bunch the facility’s requirements into several, smaller systems where the compressed gas cylinders may be set up entirely in gas cabinets.

Cryo-Source is a dependable132] distributor of hydrogen, along with various other specialty gases and specialty gas equipment to the Portland area. Whether you need specialty gases for use in your laboratory research, or any other industry in Portland, Cryo-Source will have the products you need to complete your tasks. To find out more about Cryo-Source and our specialty gas products in Portland, browse our website and catalog. We can be reached at 503-235-0168 or via email at paulb@industrialsource.com
 
 
 
Larry Gallagher
CONCOA 
2/10/2016