Safely Using Hydrogen In Laboratories

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

With escalating costs associated with the limited volume of available helium, those who operate and design 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.  Nonetheless, it is extremely important to comprehend the risks that are posed through the use, distribution, and storage of hydrogen along with the fire and safety code regulations 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 altered the Maximum Allowable Quantities (MAQ) spelled out specifically for hydrogen. These MAQ’s are distinguished for each storage area, determined by storage in either an unsprinklered or entirely 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 in cylinders are stored in additional areas rather than simply gas cabinets, the MAQ is restricted to 1,000 cuft, whereas that quantity is multiplied to 2,000 cuft if all cylinders are stored in gas cabinets. Likewise, for sprinklered units where not all cylinders are stored in gas cabinets, the MAQ is also 2,000 cuft. That amount is multiplied to 4,000 cuft if all cylinders are stored in gas cabinets. NFPA further states limitations defined by hydrogen use in control areas or utilizing outside storage, part II of this series will detail the infrastructure necessities for compliance.

We will elaborate on our discussion by selectively describing some of the primary areas and requirements for hydrogen installation in regards to fire-resistance rating and ventilation.Section 6.3.1.3.1 of NFPA details that for flammable gases kept or used in amounts greater 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 fire-resistant wall; however, they must be separated by 20’ or a noncombustible wall containing a minimum fire resistance rating of .5 hours from incompatible elements like oxygen. For areas that have hydrogen systems, necessary safety notices must likewise be permanently set up.

In Addition, 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 has proved to be sufficient for the gas utilized. If being ventilated mechanically, 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 armed with an emergency power system for alarms, vents, and gas detection. The system must also account for gas density to guarantee sufficient exhaust ventilation. Part III of this series will detail the remaining NFPA 55 requirements for separation and controls.

To further explain the series discussing updates to NFPA 55 regulating the proper utilization of hydrogen in laboratories, we will continue our discussion selectively describing some of the primary areas and requirements for hydrogen installation in reference to separation and controls.Section 7.1.6.2 of NFPA 55 states that any flammable or oxidizing gases must be separated by 20’ from each other, while section 7.1.6.2.1 states that this distance can be limitlessly decreased 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 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 operate fail-safe. Section 2703.2.2.1 of the IFC calls for 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 dictates that these brazing materials should have a melting point greater than 10,000°F.Aside from piping requirements, these codes also demand 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 about the the proper use of hydrogen in labs, we will close our explanation by detailing employments where the need for hydrogen gas cylinders is higher than the Maximum Allowable Quantities (MAQ’s).

It is quite typical to encounter 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 smaller than 150 PSIG is not achievable . The NFPA 55 code along with the IBC and IFC requirements will allow for these volumes to be present inside a building; however, certain building improvements are necessary, effectively requiring that the facility build a hydrogen shelter. These upgrades consist of improvements 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 more effective solution would be to bunch the facility’s requirements into several, smaller systems in which the compressed gas cylinders can be installed completely in gas cabinets.

Wright Brothers is a reliable132] distributor of hydrogen, along with several other specialty gases and specialty gas equipment to the Cincinnati area. Whether you require specialty gases for use in your laboratory research, or any other industry in Cincinnati, Wright Brothers will have the products you need to complete your tasks. To find out more about Wright Brothers and our specialty gas products in Cincinnati, browse our website and catalog. We can be reached at 800-637-2222 or via email at mike@expectthebest.com
 
 
 
Larry Gallagher
CONCOA 
2/10/2016