Safely Using Hydrogen In Laboratories

Sidney Lee Medical & Scientific Gases supplies a large selection of hydrogen to Atlanta, GA, along with various other specialty gases. Sidney Lee Medical & Scientific Gases quite often supplies hydrogen and other specialty gases to research laboratories and various other industries, so we felt it would be helpful for our Atlanta, GA customers to be updated on the safe use of hydrogen in laboratories.

With escalating costs associated with the limited helium supply, operators and designers of laboratory equipment are increasingly 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.  Still, it is vital to be cautious of the risks that hydrogen storage, distribution, and use present along with the fire and safety code rules governed 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) specifically established for hydrogen. These MAQ’s are discerned for each storage area, affected by storage in either an unsprinklered or fully sprinklered building and further limited 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 restricted to 1,000 cuft, whereas that number is multiplied to 2,000 cuft if all cylinders are stored in gas cabinets. Likewise, for sprinklered rooms that do not have all cylinders 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 states limitations determined by hydrogen use in control areas or using outside storage, part II of this series will discuss the infrastructure necessities for compliance.

We will continue our discussion by selectively describing some of the primary areas and needs for hydrogen installation in regards to fire-resistance rating and ventilation.Section 6.3.1.3.1 of NFPA explains that for flammable gases kept 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 require separation by 10’ or a nonflammable wall; however, they require separation by 20’ or a fire-resistant wall containing a minimum fire resistance rating of .5 hours from incompatible elements like oxygen. For locations containing hydrogen systems, appropriate safety signs must likewise be permanently set up.

In Addition, Section 6.16 states that use and storage areas that are indoors must be provided with ventilation, either mechanical or natural, so long as the natural ventilation is proven to be acceptable for the gas used. If using mechanical ventilation, 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 keep track of gas density to assure proper exhaust ventilation. Part III of this series will expand on the remaining NFPA 55 requirements for separation and controls.

In continuing the series detailing updates to NFPA 55 ensuring the safe employment of hydrogen in laboratories, we will further our discussion selectively addressing some of the primary areas and requirements for hydrogen installation in regard to separation and controls.Section 7.1.6.2 of NFPA 55 dictates that any flammable or oxidizing gases must be separated by 20’ from each other, while section 7.1.6.2.1 dictates that this space can be limitlessly decreased 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 declared by NFPA 55, IFC, & IBC, creating a slightly more nuanced neccessity for compliance. Section 414.4 of the IBC demands that controls must be sufficient for the intended application, with automatic controls being required to work without fail. Section 2703.2.2.1 of the IFC demands suitable materials for hazardous media, the main consequence 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 requires that these brazing materials should have a melting point greater than 10,000°F.Aside from piping requirements, these codes also call for 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 concluding part in the NFPA 55 series governing the the proper use of hydrogen in labs, we will conclude our discussion by explaining uses where there is a greater demand for hydrogen gas cylinders than the Maximum Allowable Quantities (MAQ’s).

It is not unusual to come across installations where the requirement for hydrogen is larger than the MAQ’s, frequently in instrumentation uses 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 smaller than 150 PSIG is unable to be obtained . The NFPA 55 code along with the IBC and IFC requirements will allow for these volumes exist within a building; however, significant upgrades to the building are required, effectively demanding that the facility constructs a hydrogen shelter. These upgrades consist of advancements to the structure fire rating, transportation, fire detection, a restraint on the amount of occupants, and a restraint on the amount of stories of the building. 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 group the facility’s requirements into several, smaller systems within which the compressed gas cylinders can be installed completely in gas cabinets.

Sidney Lee Medical & Scientific Gases is a trusted132] distributor of hydrogen, along with several other specialty gases and specialty gas equipment to the Atlanta, GA area. Whether you are in search of specialty gases for use in your laboratory research, or any other industry in Atlanta, GA, Sidney Lee Medical & Scientific Gases will have the products you need to carry our your operations. To find out more about Sidney Lee Medical & Scientific Gases and our specialty gas products in Atlanta, GA, browse our website and catalog. We can be reached at 770-946-4287 or via email at Grace.hoffman@sidneylee.com
 
 
 
Larry Gallagher
CONCOA 
2/10/2016