I see they sell special RV fresh water hoses. What is the difference between these and a regular garden hose (besides a few bucks)? It must be that the RV hoses don't hold bacteria or something like that. I don't know.
Generally speaking, the "special" hoses are made from materials qualified for drinking water. Regular garden hoses may be constructed with materials that contain harmful chemicals that could leach intothe water.
I believe the difference comes into play when the hose is used for a supply hose for a longer period of time like weeks or months. If a cheap vinyl hose contains water under pressure, some of the plastic may leach into the water.
It's not that they are "RV" hoses, it's that they are "potable water" hoses. As the others have said, a potable water hose is rated safe for carrying drinking water. Garden hoses are not. Most garden hoses also impart a rather nasty taste to the water, again because of the chemicals used in the vinyl.
In RV use, the white color of potable water hoses is a good color code. I carry two hoses, one white one for potable water ONLY. The other is a 25 foot piece of cheap green hose I use for waste tank and sewerage work. The two are stored in separate storage compartments. The white hose is always stored with its two ends coupled together to seal off the hose. An old white hose is discarded, never retained for other uses.
It's not really that many Karl, but I do admit to carrying rather a lot of fire fighting stuff (multiple extinguishers including my special "Campfire" extinguisher (A 1 1/2 gallon garden sprayer rigged so it's easier to pressurize) (I might add it has a broken pump too)
I'm going to cut down on them a bit when I get the improved solution so I'll have black, green or gray and clear with dark green and gray both "Rinse") I'll pick one since with the improved solution, if it works, I won't need two any more)