This is a subjective topic.
There is so much misinformation and scare tactics surrounding this subject. My ultimate answer is that it's up to you to decide whether or not mineral oil/petrolatum/eum/whateverum is bad.
There are certainly more "beneficial" (and again, that's subjective as well) ingredients out there.
I posted this comment on
CurlyNikki's site a while back:
(mineral oil) Clear, odorless oil derived from petroleum that is widely used in cosmetics because it rarely causes allergic reactions and it cannot become a solid and clog pores. Despite mineral oil’s association with petroleum and the hype that it is bad for skin, keep in mind that petroleum is a natural ingredient derived from the earth and that once it becomes mineral oil USP (cosmetics- and pharmaceutical-grade mineral oil), it has no resemblance to the original petroleum. Cosmetics-grade mineral oil and petrolatum are considered the safest, most nonirritating moisturizing ingredients ever found (Sources: Cosmetics & Toiletries, January 2001, page 79; and Cosmetic Dermatology, September 2000, pages 44–46). Yes, they can keep air off the skin to some extent, but that’s what a good antioxidant is supposed to do; they don’t suffocate skin! Moreover, mineral oil and petrolatum are known to be efficacious in wound healing, and are also among the most effective moisturizing ingredients available (Source: Cosmetics & Toiletries, February 1998, pages 33–40).
(petrolatum). Vaseline is pure petrolatum. For some unknown and unsubstantiated reason, petrolatum has attained a negative image in regard to skin care, despite solid research to the contrary. Topical application of petrolatum can help the skin’s outer layer recover from damage, reduce inflammation, and generally heal the skin (Source: Acta Dermato-Venereologica, November–December 2000, pages 412–415). See also mineral oil.
I got both definitions from cosmeticscop.com, and I am inclined to believe her statements because she actually cites reputable sources instead of just throwing something out there like a lot of people tend to do. Here are more links I think you should read before I make my final argument (made by actual scientists):
http://thebeautybrains.com/2006/11/28/the-top-5-myths-about-mineral-oil-part-1/
http://thebeautybrains.com/2006/12/01/myths-about-mineral-oil-part-2/
Now, I hear a lot of people say bad things about mineral oil and petroleum, and all of those comments tend to be incredibly unnerving. The reason why is because while people can make all the claims they want about it, NO PERSON I'VE COME ACROSS HAS EVER BEEN ABLE TO PROVIDE A REPUTABLE SOURCE JUSTIFYING THEIR CLAIM. THAT LEADS ME TO BELIEVE THAT WHAT THEY ARE SAYING JUST ISN'T TRUE.
Have you ever actually heard of a person developing cancer from using products that contain mineral oil and/or petroleum? (If this was the case my paternal Grandmother-who sadly STILL wears a curl-would be dead right now^_^.) I know I haven't read about it or seen a single study that justifies this claim. It's just a scare tactic surrounded by a ton of misinformation. Seriously, if mineral oil caused cancer, we would all be deader than a doorknob.
Personally I ignore the debate about oils moisturizing or conditioning because, IMO, when you condition your hair it just means that you are restoring moisture to your hair specifically after you wash it (meaning you are moisturizing it). That wasn't the basis of my post. I was challenging the hype behind using natural oils and their inabilities (which people tend to ignore or be ignorant of because it's a natural product-so it should work in any way that you want it to...right?...Not really...).
fyi evoo, coconut, and avocado CAN actually penetrate into your hair, not just your scalp:
http://thebeautybrains.com/2006/07/08/beauty-q-a-is-oil-good-for-your-hair/
http://thebeautybrains.com/2007/05/14/two-natural-oils-that-make-your-hair-shiny-and-strong/
There are other sources, but I just don't feel like looking right now. ^_^