Cryogenic fluids (cryogens) exhibit extremely low boiling-point temperatures (at atmospheric pressures), typically less than 170°K (-154°F/-103°C). These include liquefied atmospheric gases such as nitrogen and oxygen, along with argon, neon, hydrogen and helium. At room temperature, Carbon Dioxide is typically stored as a liquid under pressure (approximately 700 psi).
Cryogenic systems at BNL generally fall into three SBMS Subject Areas: Cryogenics Safety, Compressed Gas Cylinders and Related Systems and Pressure Safety. In addition to the requirements listed in these subject areas, the following information is provided to safety used cryogens:
Characteristics of Cryogen provide typical atmospheric boiling-point temperatures of commonly used cryogens;
Liquid Oxygen and Flammable Cryogenics Safety provides information and guidance for the mitigation of safety concerns when using Liquid Oxygen (LOX) or Flammable Cryogens (i.e., Liquid Hydrogen);
Small cryogenic storage devices (dewars) in laboratories are typically designed to be vented to atmosphere. If pressure is allowed to build up due to a blockage in its vent system (typically from contamination), the dewar is considered plugged and could cause an explosion due to the expansion of liquid to gas. Plugged Dewars provides the instructions if a dewar is suspected to be plugged;
Operating Instructions for Liquid Nitrogen Buggies provides the instructions that are posted on BNL potable nitrogen storage/transportation dewars (buggies);
Cryogenic Safety Postings provides example signs to be used in cryogen areas in either .pdf or PowerPoint (editable) formats.
Non-flammable Cryogenic Liquid Safety Assessment Methodology (SAM) provides approved packaging and transport controls approved for the safe transfer of non-flammable cryogenic liquid containers by non-Procurement & Property Management Division staff. Procurement & Property Management Division staff uses internal procedures and receive specialized training in the packaging and transport of cryogenic liquids.
Cryogenic Personal Protective Equipment (PPE) provides guidance and suggestions for appropriate face and hand protection while using cryogens.
Last Modified: March 16, 2012