Safely Using Hydrogen In Laboratories

Cee Kay Supply, Inc. carries a large selection of hydrogen to St. Louis, along with several other specialty gases. Cee Kay Supply, Inc. frequently supplies hydrogen and other specialty gases to research laboratories and several other industries, so we felt it would be useful for our St. Louis customers to be updated on the safe use of hydrogen in laboratories.

With increasing costs correlated with the limited helium supply, 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 vital to comprehend 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 changed the Maximum Allowable Quantities (MAQ) spelled out specifically 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 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 amount is doubled to 2,000 cuft if all cylinders are stored in gas cabinets. Similarly, for sprinklered rooms 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 has limitations determined by hydrogen use in control areas or employing outside storage, part II of this series will discuss the infrastructure demands for compliance.

We will extend our discussion by selectively describing some of the main areas and requirements for hydrogen installation in regards to fire-resistance rating and ventilation.Section 6.3.1.3.1 of NFPA states that for flammable gases stored or used in quantities larger 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; but, 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 with hydrogen systems, necessary safety placards must be permanently placed as well.

Additionally, Section 6.16 declares that storage and use areas that are inside must be ventilated either mechanically or naturally, so long as the natural ventilation is proven to be acceptable for the gas used. If being ventilated mechanically, 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 being armed with an emergency power system for alarms, vents, and gas detection. The system must also keep track of gas density to guarantee sufficient exhaust ventilation. Part III of this series will discuss the other 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 further 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 dictates that any flammable or oxidizing gases are required to be separated by 20’ from each other, while section 7.1.6.2.1 declares that this space can be limitlessly lowered 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 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 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 demand the employment 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 hydrogen’s correct use within laboratories, we will conclude our discussion by describing applications where the Maximum Allowable Quantities (MAQ’s) is less than the demand for hydrogen gas cylinders.

It is not unusual to come across installations in which the need for hydrogen is greater than the MAQ’s, typically in instrumentation applications and/or chemical reactions like hydrogenation. These are often encountered in installations using hydrogen where outside storage is unavailable and control to line pressures of less than 150 PSIG is unobtainable . The NFPA 55 code along with the IBC and IFC requirements will allow for these volumes to be present inside a building; however, important enhancements to the building are necessary, effectively demanding that the facility constructs 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. Not only this, but these installations likewise have strict requirements in regards to distancing along with floor and wall ratings. Although feasible, this scenario is not ideal and should be avoided if possible. A more effective solution would be to group the facility’s requirements into many, smaller systems in which the compressed gas cylinders may be inserted exclusively in gas cabinets.

Cee Kay Supply, Inc. is a reliable132] distributor of hydrogen, along with several other specialty gases and specialty gas equipment to the St. Louis area. Whether you need specialty gases for use in your laboratory research, or any other industry in St. Louis, Cee Kay Supply, Inc. will have the products you need to carry our your operations. To find out more about Cee Kay Supply, Inc. and our specialty gas products in St. Louis, browse our website and catalog. We can be reached at 314.644.3500 or via email at benv@ceekay.com
 
 
 
Larry Gallagher
CONCOA 
2/10/2016