Our calibration gases are provided by GASCO. They are a leading supplier of environmental and industrial safety calibration gases. You can purchase GASCO calibration gases online here. If you have a Grainger account, you can purchase calibration gas online and have it delivered to your local Grainger store.
Calibration gas cylinders ship as hazardous material. This is due to the danger of shipping compressed gas - not from a chemical hazard. Once the cylinders are relieved of pressure they are NOT considered hazardous material or waste.
For disposal of empty gas cylinders, it is acceptable to place them in a landfill. They present no danger to the environment. The cylinders contain absolutely no liquid residue and are clean internally as required for gas mixture stability. As an example for comparison, a typical household cylinder of propane or an empty spray paint aerosol would contain enough residual to be of far greater environmental concern than a calibration gas cylinder.
We recommend recycling cylinders. GASCO has an Eco-Smart line of cylinders they offer that are recyclable. After the cylinder is empty, GASCO will send you a shipping label and you can return it for free.