Management of Unwanted Gas Cylinders

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Key Takeaways

  • Check pressure of cylinders before disposal 
  • Cylinders containing hazardous waste must be labeled and disposed of properly
  • Purchase cylinders from companies that accept returns

Requirements and Cost Considerations

Researchers and authorized users are required to properly manage gas cylinders, or to purchase cylinders from companies that accept them for return. While many larger cylinders purchased from approved vendors are well managed, certain specialty gasses or blends may be challenging to return.  

  • Disposal costs for lecture bottles that cannot be returned can cost from $100 per cylinder for inert gases to over $1,000 for unusual or highly toxic gases.
  • The cost of managing these cylinders is among the costs of performing your research.  

Please notes that OARS and ECOS does NOT routinely collect or manage compressed gas cylinders, including lecture bottles, for hazardous waste disposal.

Purchasing Guidelines

First, check to see if there is surplus on campus.  If none are available, then purchase your gas in a returnable and/or refillable lecture bottle or cylinder from approved vendors. Contact your sales vendor to learn more about newer technologies and alternatives to lecture bottles.   

  • Create a plan for the proper management of the lecture bottle when it is empty or no longer needed.  
  • For other cylinder sizes, please work with the University’s Procurement Office to ensure compressed gas cylinders are being purchased from approved vendors that can accept returns. 

Gas Cylinder Returns 

Approved vendors will accept cylinders that are empty or no longer needed. If a cylinder is not from an approved vendor,

  • contact the provider to confirm their return policy. Follow the instructions given by the vendor to ship or return a cylinder,
  •  request information about returns and shipping if not readily available.    

 

Management Options for Partially Full Lecture Bottle 

If you are done using a  partially full lecture bottle, please repurpose by finding someone within the University that can use it, otherwise it should be returned to the manufacturer.  Reach out to our office if you have questions about venting specific gasses.

  • If the gas is non-hazardous (air, argon, carbon dioxide, helium, krypton, neon, nitrogen or xenon) then you may safely vent the gas to the fume hood.
  • Once the cylinder is empty, you must remove the valve and the remaining metal-carcass –can to recycle as scrap metal. NU Recycling at Facilities will pick up empty cylinders upon receipt of a work order request.
  • If a cylinder contains a poisonous or hazardous gas and none of the above options are workable, then it may be disposed of as a hazardous waste. 

Removing Valves from Cylinders 

Removal of valves from cylinders can pose a significant hazards if they are not fully discharged or if hazardous chemical residues are present. Cylinders that held flammable gases may still present a fire or explosion hazard, while those that held corrosive, poisonous, or reactive gases may still have sufficient residues to cause injury and harm.

  • Confirm chemical hazards by referencing Safety Data Sheets (SDS). Remaining residues may require it to be managed as a hazardous waste.
  • All pyrophoric materials should be excluded from this procedure.
  • Eye protection and gloves should be worn whenever attempting to safely remove valves from lecture bottles. 

Ensure that the cylinder is empty.

Visually inspect valves to see if there are obvious physical defects or corrosion. If defects or corrosion are observed,  do not attempt to manipulate the valve. Cap or plug the outlet and dispose of as a hazardous waste. If the valve appears to be safely operable, check the gas pressure within the lecture bottle by attaching the correct Compressed Gas Association pressure regulator. Once the pressure, if any, had been determined, remove the regulator and then place the lecture bottle in a fume hood and carefully open the valve. Allow the lecture bottle to set for a few minutes to assure that the pressure inside it is at the ambient level. 

Remove the Valve

Assess possible hazards from gaseous residues and select personal protective equipment as appropriate. Place the empty cylinder in a vise and remove the valve. The cylinder can then be managed by NU Recycling. All labels on the lecture bottle should be defaced. 

Hazardous Waste Disposal

Any cylinder that is not returnable or cannot be managed on site will require management as a hazardous waste.

Labeling

All cylinders that are hazardous must be

  1.  labelled clearly  as “hazardous waste”
  2.  list the date when the waste container was declared a waste, 
  3.  list the physical hazards of the waste (e.g. corrosive), and
  4. identify all of the chemicals or chemical mixtures.

Hazardous waste disposal labels are available by submitting a request through SciShield (formerly BioRAFT) and should be used when declaring a material to be a hazardous waste.

Please submit a request in advance so that the labels may be delivered to your laboratory prior to the scheduled pick-up. In addition to the above labeling requirements, the approximate pressure (psi) must also be noted on the label. 

ECOS - Hazardous Waste

Waste Minimization and Recycling

Waste minimization a national policy, an institutional value and a goal of each waste generator. As a user of compressed gases,you  have the responsibility to minimize the amount of gas managed as a hazardous waste.

Waste minimization has benefits such as decreasing your exposure to hazardous substances, protection of the environment, and the overall reduction in the cost of disposal which frequently can exceed the original cost of the gas by 10 or more times.

Waste minimization includes reviewing and changing procedures, reducing scale and substituting materials.

If you have gases that are no longer in use and are ready to recycle, please flag the cylinder as “Surplus” in SciShield’s ChemTracker module and contact our office.  

Access ChemTracker

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