Due to lack of disposal options and outlets for waste gas cylinders, disposal of these items presents a special problem for the Chemical Waste Program. The few disposal companies which accept gas cylinders generally require certification that the cylinders are equipped with working valves and the contents of the cylinders are known.
The Chemical Waste Program has two possible disposal options - a disposal company may:
vent the cylinder into a chemical waste incinerator or into the flow of another chemical treatment process; or
recapture the cylinder contents and recycle the gas.
Both of these options cost from $300 to $10,000 per cylinder depending on size and contents. Therefore, all purchase orders for new cylinders must state that the vendor will accept the return of the empty or partially empty cylinder from the University.
It is very important that users of gas cylinders prevent damage to the cylinders and valves and keep the cylinders properly labeled as to their contents. It is very expensive to analyze an unknown cylinder and even more expensive to transfer the contents of a damaged cylinder into a DOT approved cylinder.
Arrangements should be made at the time of purchase for return of the cylinders.
Compressed gas cylinders should be submitted for collection according to the following procedures:
Return gas cylinders, whether empty or partially filled, to the manufacturer or distributor through which they were purchased. If the manufacturer will not accept the cylinders for disposal, they should be purchased through another supplier. If originally purchased through the University storehouse, contact the University Stores at (612) 624-2094 to make arrangements for return of gas cylinders.
Use up all of the gas in a cylinder to render it empty if at all possible. Empty cylinders should be clearly marked as empty to avoid confusion when it comes to return or disposal of the cylinder. Do not vent full or partially used cylinders into fume hoods as a means of disposal.
In the event, it is not possible to return the cylinders as specified above, submit the cylinders for waste pickup by the Chemical Waste Program following normal disposal procedures. Make sure the cylinders are clearly marked as to contents and valves are properly sealed and capped.
Empty disposable propane and butane bottles should be submitted for waste collection by the Chemical Waste Program in accordance with normal University hazardous waste disposal procedures.
Dispose of aerosol cans according to the following procedures:
Chemical products in aerosol cans should be used up in their intended manner whenever possible. When aerosol cans are empty (at atmospheric pressure), they may be disposed of in the trash.
If the aerosol can is not empty, submit for waste collection by the Chemical Waste Program. Note that in packaging, the cans should stand upright in the box and be capped to prevent the release of contents. If the ingredients of the can are known, list them on the waste form with the respective percent composition. If a commercial product, list company name, location and any hazard information listed on the can.