Safely Using Hydrogen In Laboratories

Spec Air Specialty Gases carries a large selection of hydrogen to Auburn, along with many other specialty gases. Spec Air Specialty Gases frequently supplies hydrogen and other specialty gases to research laboratories and several other industries, so we felt it would be useful for our Auburn customers to be updated on the safe use of hydrogen in laboratories.

With increasing costs related to the limited helium supply, those tasked with operating and designing laboratory equipment are beginning to turn more frequently 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 extremely important to comprehend the risks that hydrogen storage, distribution, and use present along with the fire and safety code regulations 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) spelled out specifically for hydrogen. These MAQ’s are identified for each storage area, decided by storage in either an unsprinklered or completely 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 quantity is increased 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 defines limitations determined by hydrogen use in control areas or employing outside storage, part II of this series will explain the infrastructure requirements for compliance.

We will elaborate on our discussion by selectively describing some of the primary areas and requirements for hydrogen installation in terms of fire-resistance rating and ventilation.Section 6.3.1.3.1 of NFPA details that for flammable gases kept or utilized in greater quanities 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 fire-resistant wall; but, they need to be separated by 20’ or a noncombustible wall that contains a minimum fire resistance rating of .5 hours from incompatible materials like oxygen. For places having hydrogen systems, appropriate safety placards must likewise be permanently set up.

Additionally, Section 6.16 details 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 function 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 armed with an emergency power system for alarms, vents, and gas detection. The system is also tasked with accounting for gas density to assure sufficient exhaust ventilation. Part III of this series will discuss the remaining NFPA 55 requirements for separation and controls.

To further explain the series discussing updates to NFPA 55 ensuring the safe employment of hydrogen in laboratories, we will continue our discussion selectively describing some of the important areas and requirements for hydrogen installation in regard to separation and controls.Section 7.1.6.2 of NFPA 55 states that any flammable or oxidizing gases are required to be separated by 20’ from each other, while section 7.1.6.2.1 dictates that this space 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 dictated by NFPA 55, IFC, & IBC, creating a slightly more nuanced need for compliance. Section 414.4 of the IBC demands that controls must be good enough 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 consequence 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 higher 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 last section in the NFPA 55 series governing the safe use of hydrogen in 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 not unusual to find installations where the requirement for hydrogen is larger than the MAQ’s, most often in instrumentation employements and/or chemical reactions like hydrogenation. These are commonly found in installations using hydrogen where there is no outside storage available and control to line pressures of less than 150 PSIG is unable to be obtained . The NFPA 55 code combined with the IBC and IFC requirements will allow for these volumes be in a building; however, certain building improvements are necessary, effectively requiring that the facility constructs a hydrogen shelter. These upgrades consist of improvements 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. 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 effective solution would be to parcel the facility’s requirements into many, smaller systems where the compressed gas cylinders may be set up completely in gas cabinets.

Spec Air Specialty Gases is a reliable132] provider of hydrogen, along with many other specialty gases and specialty gas equipment to the Auburn area. Whether you are in search of specialty gases for use in your laboratory research, or any other industry in Auburn, Spec Air Specialty Gases will have the products you need to carry our your operations. To find out more about Spec Air Specialty Gases and our specialty gas products in Auburn, browse our website and catalog. We can be reached at or via email at orders@specair.com
 
 
 
Larry Gallagher
CONCOA 
2/10/2016