What safety rules should I follow when welding?

Both in the case of professional use and in the case of domestic use, it is necessary to be scrupulous in following the safety rules:
Buy a welding machine from a reliable brand and a recent model: first of all it is good to make sure that you have a welding machine made in a workmanlike manner, that is in full compliance with safety standards. Old models may not be completely up to standard
Always wear all safety devices (sometimes they are sold together with the welding machine: otherwise they must be purchased separately)
Be careful not to inhale the gases emitted during welding, as they can be toxic and harmful to health.
Keep away from the place where you are welding flammable substances (as we have seen, the jets of the welding could cause a fire)