Experiment Hazard Class 2 – Cryogenic Systems

Applicability

This hazard classification applies to all experiments involving the use of cryogenic systems.

Experiment Hazard Control Verification Statements

General requirements

The use of detectors/alarms, warning signs, and adequate ventilation are recommended for areas where release of a cryogen can result in an oxygen-deficient atmosphere. Cryogenic systems and vessels are always insulated to reduce heat exchange and are labeled with the common name of the cryogen. Cryogenic systems are pressure protected and equipment are insptected and maintained. The use of flammable cryogens requires technical consultation. Initial consultation may be obtained from the divisional ESH Coordinator. A written emergency evacuation response plan must be available in the work area. In any emergency DIAL 911

Storage of cryogenic liquids

  • Compatibility of storage vessel to cryogen
  • Storage vessel is suitably designed and constructed to handle cryogens and in accordance with professional standards i.e. 49 CFR 178, the ASME Boiler and Pressure code VIII (Division I) and DOE order 420.1, Facility Safety
    Note: Consultation with knowledgeable Argonne personnel can be obtained by contacting the Argonne Pressure Technology and Safety Committee chair or the FMS pressure safety engineer.

Pressure Hazard Controls

  • No part of a cryogenic system can be isolated from a pressure relief device
  • Pressure relief devices cannot be circumvented
  • Pressure relief device has the capacity to handle the worst case scenario without rupture to the system
  • MAWP (maximum allowable working pressure), the pressure relief device is at or below this value
  • Pressure relief devices are to be inspected periodically to confirm operation and verification that the device has not been tampered with or isolated from the system
  • Vents and relief valves discharge to a safe location

Procedural Controls

  • Inform users of the properties and hazards of the cryogen prior to use. Verify that users are trained in the SOPs, are aware of emergency response plans, and that the proper wearing of PPE prior to work with cryogenic liquids are used
  • Potential consequences of an accidental release
  • Documented safety review before commissioning of a cryogenic system
  • FMS site services must transport any dewar 25 liters or greater by vehicle from one building to another when requested.
  • Transporting containers and dewars will be done following the guidelines in Section 4.10.12 Laboratory-wide Procedure: Hazardous Materials - Cryogenic Liquid Safety

Design Reviews and Equipment Inspections

  • Documented safety review of the cryogenic system
  • Ensure dewars or vessels are dry prior to filling the container with a cryogen
  • Verify integrity of storage vessels, dewars, and pressure relief devices; vessels owned by ANL-E are to inspected every 3 years
  • Inspect all systems, distribution networks, devices associated with cryogenic liquids

Training – Prior to using a cryogenic liquid or system, content should include:

  • Physical, chemical and physiological hazards associated with cryogenic liquids (MSDS)
  • Specific handling hazards in the work environment
  • Descriptions, drawings, and function of the cryogenic container and distribution system
  • Required engineering and administrative controls
  • Review safe operating procedures
  • Proper use of personal protective equipment
  • A written emergency evacuation response plan is available in the work area
  • First aid measures in the event of an exposure or injury; cold contact burn, immerse body part in tepid water, do not rub body part, DIAL 911
  • Inspection and maintenance schedules and procedures
  • ESH-145 Cryogenic Safety is provided by ANL

Signs and Labeling – Cryogenic systems and equipment are to be labeled with the common name of the cryogen; some of the signs may be obtained from the AES or XSD ESH Coordinators.

Personal Protective Equipment (PPE) – safety glasses with sideshiles (ANSI Z87.1), full face shield, insulating gloves or gauntlets, loose clothing covering arms, trousers without cuffs over shoes tops, safety shoes that cover the entire foot and are made of nonabsorbent material upperst i.e. leather. Non-prescription safety glasses and face shields are available in the APS stockroom

Hazard TIPS

  • If liquid boils; gas pressure may build from heat transfer of room temperature environment to cryogenic temperatures
  • Frostbite may occur if exposure
  • Physical properties of materials may change when exposed to cryogenic liquids
  • Oxygen condensation from atmosphere with liquids that have boiling points below liquid oxygen. Repeated replenishment of a system may cause oxygen to accumulate as a contaminant. Fire or explosion could occur if combustibles are present
  • Oxygen deficient atmosphere can occur because of cryogenic displacement. (May need to be calculated by an SME)
  • Grabber-type hand tools should be used when applicable

References

Updated: March 25, 2013 Reviewed:March 25, 2013