Hbbg: Petroleum-based products are all made in some way from crude oil. Petroleum jelly (vaseline) is one petroleum derivative, but only one of hundreds (thousands?). Petroleum is used to make detergents, plastics, artificial fragrances ("perfume oils"), stabilizers I think, synthetic fabrics, and also artificial flavors, preservatives & fertilizers. I'm probably leaving some things out as well

The extent to which our society relies on various petroleum products now is boggling.
I try to avoid petroleum-based ingredients for several reasons. First, I'm not convinced that they're good for us (see the threads on toxic plastic) especially when they're in something that comes in direct, repeated contact with my skin. I keep in mind that petroleum derivatives are enormous business for all the industries that use them in myriad applications, so I don't have much confidence in getting unbiased studies about their safety.
Second, I don't want to rely on the petroleum industry any more than I have to. A green-powered car isn't in the picture for us right now, but I try very hard to cut back on gas & the other petroleum products our family consumes. One of the reasons I like to use homemade no-poo recipes is that even the most natural storebought product would require me to buy something in plastic bottles regularly. (I get my acv in bulk at my health food store, so I can use the same plastic bottle over & over again, or I can use a glass Mason jar, a Ming porcelain vase, a clay amphora -- whatever floats my boat :LOL)
Third, I don't think petroleum-based products are good for my skin & hair. Petroleum-based detergents are really harsh, and mineral oil is really coating & suffocating (plus with mineral oil we're back to reason #1). I've been much happier with my skin and hair since I switched over to natural ingredients.