No clear instructions regarding the sorting or disposal of "gas cylinders" or "cassette gas cylinders" were found on the official Izumi City website. Confirmation required. General safety precautions and disposal suggestions (for reference if official Izumi City instructions cannot be confirmed): 1. For refillable large gas cylinders (e.g., propane), request the store where purchased or the gas supplier (utility company) to collect, recycle, or exchange them. Do not dispose of them yourself, as they are often not treated as bulky waste by municipalities. 2. For disposable canister gas cylinders (used for tabletop stoves), completely use up the contents outdoors. Do not puncture or destroy them while they still contain gas. Disposal methods vary by municipality (non-combustible waste, metal waste, hazardous waste), so confirm Izumi City's instructions. 3. For cylinders with residual contents, damage, or potential liquefied gas hazards, consult your city's environmental office or fire department. When placing them out for collection, follow any instructions to label the container (e.g., "Empty"). 4. Safety precautions: Keep away from fire, direct sunlight, and high temperatures. Do not leave containers unattended or puncture them before transport or household waste collection. Note: As the official handling procedure for Izumi City is unclear, please contact the city's environmental office (Environmental Policy Division, Living Environment Section) or waste collection office to confirm the official sorting category and disposal method.