Skip to main content

Safety

Compressed Gas

Compressed gases and cryogenic liquids are essential utilities in the clinical laboratory, powering everything from anaerobic incubators (Nitrogen/CO2) to Atomic Absorption instruments (Acetylene). However, they introduce significant hazards: high pressure (projectile risk), chemical toxicity/flammability, and extreme cold. Safe management relies on strict protocols for identification, physical handling, and protection against thermal injury

Labeling

Positive identification of cylinder contents is the first line of defense

  • The Golden Rule: “Read the label, not the cylinder.”
  • Mandatory Labels: The only legal identification is the manufacturer’s written text label or stencil on the cylinder shoulder. This must include the product name, concentration, and hazard warnings
  • Color Codes: Do NOT rely on tank color (e.g., assuming green is Oxygen). Color codes vary by industry and are not a substitute for the label
  • DOT Diamonds: Visual pictograms indicate the hazard class:
    • Green: Non-Flammable (Nitrogen, CO2)
    • Red: Flammable (Hydrogen, Acetylene)
    • Yellow: Oxidizer (Oxygen) - Must be stored 20 ft from flammables.

Transport & Storage

Cylinders are high-pressure vessels that can become missiles if the valve is sheared off

  • Transport
    • Always ensure the valve protection cap: is screwed on hand-tight before moving
    • Use a cylinder hand truck: with a safety chain. Never roll, drag, or slide cylinders
    • Elevators: Do not ride in an elevator with a cylinder (asphyxiation risk). Send it unaccompanied to a receiver
  • Storage
    • Restraints: Cylinders must be secured to a wall or bench with a chain or strap (positioned 2/3 up the body) to prevent tipping
    • Segregation: Store “Full” and “Empty” cylinders separately. Keep Oxidizers at least 20 feet away from Flammables

Cryogens

Cryogens are liquefied gases stored at extremely low temperatures (LN2 at -196°C; Dry Ice at -78.5°C)

  • Hazards
    • Tissue Damage: Instant frostbite/burns upon contact
    • Expansion: LN2 expands ~700x when boiling, creating an explosion risk in sealed containers and an asphyxiation risk (displacing oxygen) in small rooms
  • PPE
    • Gloves: Loose-fitting cryogenic gloves (so they can be shaken off if liquid enters)
    • Face: Full face shield mandated for pouring
    • Feet: Closed-toe shoes; cuffless pants covering the shoe opening
  • Handling: Store in vented Dewars (never sealed tight). Use tongs for dry ice. Never dispose of dry ice in a sink