Compressed Gas Cylinder Disposal
Introduction
Containers of compressed gas go by many names, including gas cylinders, lecture bottles and high pressure tanks. The containers of gas, even when empty, are likely to contain a residual of at least one atmosphere of the gas. Poison, flammable and corrosive gases must be properly handled to prevent injury to others or to the environment.
Departments are encouraged to rent rather than purchase gas cylinders. When the cylinder is empty, or the need for the gas is over, the gas supplier will pick up the cylinder for refilling and reuse. Cylinders which are purchased may or may not be returned to the manufacturer, while rented cylinders can be returned.
Small amounts of gas can be purchased in smaller rental cylinders rather than purchasing lecture bottles, which are difficult to dispose. Disposable cylinders are a misnomer. UWM may still need to pay for disposal.
Safe Use and Guidelines
Please follow the safe handling precautions outlined in the Gas Cylinder Safety page.
Please take every effort to maintain the labels and identity of compressed gas cylinders. Scandalous and outrageous costs are required for disposal of cylinders with unknown contents or unknown origins (i.e., manufacturers).
Return all rented cylinders promptly after their use is over.
Please contact Environmental Affairs staff at x4999 or x2883 for instructions on disposal of other gas cylinders.
Poison Gases
Poison gases (such as Nitric Oxide or Phosgene) represent a significant hazard. Special precautions not otherwise necessary become prudent when using poison gases:
- Certain poison gases (e.g., Arsine, Phosphine, Ethylene Oxide) can only be used if specific OSHA regulations and safety practices are followed.
- Emergency procedures should be made clear to all involved, including personnel from adjacent labs and building managers.
- Poison gas use after normal working hours require the approval of the Chemical Hygiene Officer for your department.
- Fume hoods and other ventilation need to be tested before use and checked frequently during the project involving poison gas.
- Notify the staff in the Environmental Affairs division of the Department of University Safety and Assurances before your first use of the poison gas.
- The University Police should also be informed about the locations and types of poison gas in use.
- Document these procedures in your lab's chemical hygiene plan. As with all chemicals, obtain and review the Material Safety Data Sheet (MSDS) for the poison gas. Maintain an extra copy of the MSDS in your department's chemical hygiene plan.
Disposal of poison gas cylinders can often cause problems. If the cylinder can not be returned to the manufacturer, UWM can face large disposal costs ($1,000 per cylinder, or more). Even cylinders that can be returned must be shipped on a vehicle which can not simultaneously carry any other hazardous materials or foodstuffs.
Atmospheric or Inert Gases
While atmospheric gases (e.g., nitrogen, argon, etc.) are generally not considered toxic (exceptions: see UWM Diving Safety Manual), these inert gases can still cause dangerous situations to occur if not handled properly. Asphyxiation can occur if too much inert gas displaces the oxygen in the air. Inert gas cylinders still have all the physical hazards associated with other gas cylinders such as high pressure.
Contact staff in UWM's Environmental Affairs Program for cylinder disposal as soon as they are no longer needed.
Oxygen and Oxidizers
Oxygen and other oxidizing gases pose additional hazards over usual compressed gas hazards. These gases can enrich an atmosphere so that combustible materials readily ignite or the combustion is accelerated. For example, clothing, paper, and cardboard are very combustible in oxygen enriched atmospheres. Likewise, never use oil, grease or other petroleum products on or near oxidizing gas cylinders.
Disposable Cylinders
While certain gases are sold in "disposable" cylinders, these cylinders should be given to hazardous waste management for proper disposal. Indicate whether the cylinder is empty or still contains product above 1 atmosphere of pressure.
Aerosol Cans
Waste aerosol cans, both empty and pressurized, are considered hazardous waste because of the remaining propellant and contents. Even an empty can, one which doesn't spray any more, often will contain enough flammable vapors or gas to rupture violently if heated enough or cut open resulting in a spark. Aerosol cans are relatively inexpensive to dispose at this time so methods to empty or drain the residuals are not cost-effective. Unintentional releases of propellants does not help our ambient air quality either.
Updated July 8, 2008 by SAK