The Advanced Photon Source
a U.S. Department of Energy Office of Science User Facility

Experiment Hazard Class 5.4 – Compressed Gas Cylinders


This hazard classification applies to all experiments involving the use of compressed gas cylinders.  Other hazard classifications and associated controls may apply to experiments in this hazard class.

Experiment Category

Experiments involving previously reviewed hazard controls are categorized as medium risk experiments.

Experiments involving new equipment, processes or materials, or modified hazard control schemes are categorized as high risk experiments.

Experiment Hazard Control Verification Statements

Engineered Controls – The establishment of applicable controls for the identification, storage, handling, and use of compressed gas cylinders, systems, and associated equipment.  Line supervisors must consider obviation of hazards by balancing storage and use of compressed gases with operational functions.  Avoid excessive inventories of compressed gases.  Select an appropriate gas pressure regulator and verify regulator’s compatibility with gas type and process conditions.

Procedural Controls – Compressed gas cylinders are considered to be either in use or in storage.  There is no provision for a standby situation.  Use work control documents or standard operating procedures to obtain a proper delivery pressure.  Consult with FMS-FEC fire protection when planning experiments that involve compressed flammable gases and pyrophoric gases. The storage of compressed flammable gases in laboratories not equipped with sprinklers or smoke detectors is prohibited.  Consult with ESQ Industrial Hygiene when planning experiments that involve toxic gas, oxygen deficiency hazards, or other nonflammable compressed gas hazards.  The Pressure Technology and Safety Committee (PTSC), upon request, can assist during the review of experiments or processes that involve compressed gas hazards.  Arrangements for consultation may be made by contacting the floor coordinators, the APS User Safety Officer, or the XSD ESH Coordinator.  Please see the Compressed Gas Cylinder Storage Guidelines for more information.

Design Reviews and Equipment Inspections – A design review is necessary for compressed gas distribution systems.

Training – Sector specific training.

Signs and Labeling – Cylinders must be labeled by the vendor.  Cylinders must conform to DOT, NFPA, and OSHA hazard communication requirements.

Personal Protective Equipment – Safety glasses and safety shoes when handling cylinders.

Monitoring – Dependent upon type of gas, application, and work environment.

Hazard Control Verification

Unless otherwise noted in the approved experiment safety plan, the PSC Deputy Associate Laboratory Director of Operations delegates the authority to authorize an experiment in this hazard class to a member of the APS Experiment Safety Review Board and resident beamline personnel having the authority to authorize experiments as listed in the ESAF system.  Approval by both the host beamline and APS Experiment Safety Review Board are mandatory prerequisites for experiment authorization.

Experiment Authorization

The PSC Deputy Associate Laboratory Director of Operations delegates responsibility for verifying that required controls are in place to the experiment On-Site Spokesperson and Beamline Management.


ANL LMS-PROC-313: Pressure System Safety 1/11/2017 (Internal link)

Contact the APS User Safety Program with any questions or if the internal links are not working properly.

Reviewed: May 5, 2020