So far as we know that gas mixing with air would cause explosion when sparks or ignition occur. Gas-lacking from a gas cooker is not easily to be detected because gas usually has little or no smell. Therefore for safety sake some city-gases are deliberately made smelly ! Old gas valve or old rubber gas pipe could cause fire hazard due to gas lacking. On the other hand, even all the devices are in good conditions might cause health hazard in long run, i.e. lung cancer ! Recently we find many chefs even house-wives are having lung cancers although they are not smokers. It is because they spend a few seconds to ignite the gas cookers at least 3 times or more every day. They would inhale the gas in these short duration. In order to prevent the above hazards, especially for those forgetful elderly house wives, it is better to use induction cookers instead of gas cookers ! If you insist to use gas cooker, in order to reduce the above hazards to minimum, (i) you may hold your breathe for 5 seconds when you are igniting the gas cooker. (ii) make sure the ventilation is good in your kitchen.
Google+Health hazard of using gas-cookers
