Wherever gas is being used and wherever gas cylinders are located, you are legally obliged to have "safety data sheets" about the gas concerned!
Such a safety data sheet must contain: identification of the gas, the risks, first aid measures, fire fighting measures, information concerning transport, symbols and labelling, and so on. For this information you can consult and/or print out the Material Safety Data Sheets (MSDS) of the gas which you handle.