Hydrogen fluoride cylinders

Highly irritating and poisonous Very soluble in water. Liquid liberates heat as it dissolves in water. The entrapment of water in an anhydrous hydrogen fluoride cylinder can cause rapid generation of heat and pressure which can lead to an explosion. Containers should never be heated to >52°C. A liquid hydrogen fluoride spill area should not be entered unless protective clothing (impervious to the compound) and a self-contained gas mask are worn Fumes in air... 

Princiotto, Laurie A, , Hydrogen Fluoride Cylinder Ruptures , Laboratory Safety Specialist, Indiana University, Dept, of Environmental Health and Safety, Creative Arts Building, Bloomington, IN., 47408-2602, http //www.ehs.indiana.edu... 

Environmental Health and Safety News Article 1 Hydrogen Fluoride Cylinder Hazard University of Maryland, July 16, 1999. 

The standard valve outlet connection in the United States and Canada for hydrogen fluoride cylinders is Connection CGA 670. A limited standard connection for hydrogen fluoride cylinders is Connection CGA 660. [7]... 

Anhydrous hydrogen fluoride is also available in cylinders, and aqueous hydrogen fluoride, either 50% or 70%, is also shipped in polyethylene bottles and carboys. Typical product specifications and analysis methods are given in Table 4. 

Chemical Reactivity - Reactivity with Water Reacts with water to form hydrogen fluoride, oxygen and oxygen difluoride Reactivity with Common Materials Reacts violently with all combustible materials, except the metal cylinders in which it is shipped Stability During Transport Stable Neutralizing Agents for Acids and Caustics Not pertinent Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

The apparatus consists of a simple vacuum manifold similar to that shown in Fig. 4. The vacuum manifold should be fabricated from nickel or Monel metal, with silver-soldered or Swagelok connections. Valves should be of Monel metal, and the traps and scrubber, the function of which is to remove hydrogen fluoride vapor from the C103 F product, may be constructed conveniently of poly(chlorotrifluoroethylene) (Kel-F) tubing. A nickel cylinder of 500-ml. or 1-1. capacity serves as a reaction vessel, and a 500-ml. Monel bulb or similar vessel may be used as a product receiver. The scrubber (about 1-in. o.d.) is charged with pellets of sodium fluoride prepared in a separate operation by heating sodium... 

General Procedure. Liquid hydrogen fluoride (b.p. 19.4°) containing only 0.1-0.2% of water is available commercially in steel cylinders. It is highly corrosive to tissue,182 and the vapors are very toxic. Consequently, it should be handled with care goggles and rubber gloves must be worn. With heed to these precautions hydrogen fluoride can be handled safely and easily. 

The fluorine produced is either immediately used to prepare other final products or is first liquefied and delivered in steel cylinders where required. When fluorine is liquefied it is first led from the electrolyzer through a steel coil cooled to — 90 °C by dry ice. It then passes through a coil submerged in liquid oxygen, (— 183 °C) to separate the remaining traces of hydrogen fluoride, carbon dioxide and tetrafluoromethane. The product still contains a small... 

It is well known that anhydrous nonoxidizing inorganic acids such as hydrogen chloride and hydrogen bromide do not dissolve metals. These two compounds are stored in steel cylinders without any appreciable corrosion of the metal. The same was true of anhydrous hydrogen fluoride that was stored and delivered in steel cylinders for the past seven decades. 

Over long periods of time (20-24 years), a slow reaction takes place between anhydrous hydrogen fluoride and the steel of the cylinder. In this way, hydrogen is generated and is responsible for the high pressure inside the cylinder. 

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