WorkSafe New Zealand provides these tips on gas safety in caravans...
Remember to get the gas installations on your caravan checked once a year by a licensed gas fitter and if you smell gas, turn off the cylinder valve if it’s safe to do so, get people out of the area, turn off all appliances and ventilate your caravan. Don’t use any electrical devices , including switches and phones, until the air is clear.
Source: business.govt.nz