In NYC I have seen Dominican homes piping natural gas through copper pipe!
I'm a licensed gas fitter among other things at home. In mi casa, garden hose is used to connect two stoves to the gas supply held in place with a screw clamp. More garden hose connecting the tank to the piping that runs through the walls. I have no idea what is used in the walls, I shudder to think. Never intended for the conveyance of gas under pressure, these hoses are old and brittle. Needless to say, the tank is turned off when we are not actually cooking something. I am trying to find some NA regulation flex hose in the DR but haven't found the right place yet. If I can't find it, I'll ship some in. This is a hazardous situation that is easily fixed and should never have been allowed in the first place.
There are problems with the electrical wiring in this place as well. Phantom power everywhere and without a ground installed, I get a shock every time I touch the metal hinge on the freezer door. Building a house here is a full-time job. You have to approve every single item being used and ensure it is all installed correctly. Take a break for lunch and you'll come back to a joist secured with duct tape guaranteed.