Monday, 19 March 2012

Is mineral oil dangerous? Part 2


I'm looking at whether mineral oil, an incredibly common moisturiser - possibly the most common moisturiser, check your moisturiser's ingredients - is dangerous again. Read part 1 here!


3. Mineral oil is comedogenic and will make you break out - FALSE


Mineral oil appears on a large range of "comedogenic ingredients" lists. Once upon a time (well, in the 1970s), cosmetic companies noticed that a lot of women started getting acne from their makeup products. One scientific study on comedogenicity used the inside of a rabbit's ear to test whether products caused pimples, and this quickly became the test of choice. However, later on, they found that sometimes the results on a rabbit and the results on a human were different. (Lab Muffin loves rabbits, and this made her sad, because an awful lot of rabbits got ear pimples for no good reason!)


A later study tested products containing between 0 and 30% mineral oil, and found that it wasn't comedogenic on human skin. The best thing about mineral oil is that (unlike a lot of plant oils) it's incredibly stable - it doesn't oxidise, and stays liquid. In other words, it's not likely to clump up later on, after reacting with oxygen and light, and clog your pores! However, this doesn't mean that it won't cause you to break out, since different people respond differently to certain ingredients.



4. It just sits on top of skin - it doesn't moisturise! It suffocates your skin - PARTLY FALSE


Remember this post on moisturisers? There are three ways in which moisturisers moisturise - occlusive (covering your skin up so water can't evaporate), humectant (grabbing water and keeping it next to your skin) and emollient (makes your skin feel soft) actions. Mineral oil is an excellent occlusive, so yes, it does just sit on top of your skin - but it definitely moisturises! In fact, scientists often use it as a standard for comparing other moisturisers. Of course, if you have dry skin to begin with, just putting mineral oil isn't going to work so well (if there's not enough water to begin with, there's not much water to keep in!).

As to whether skin can be suffocated - skin is porous, but it doesn't really need to "breathe". What people usually mean by "letting your skin breathe" means washing off the dirty gunk from your pores... dirt can stick to mineral oil, just like it can stick to anything else on your face.

Because mineral oil is really good at being an occlusive, it's possible that it can block certain nutrients in your cream from reaching your skin - the solution is to put on the active ingredient first, then cover it up with the mineral oil, and the mineral oil will keep that stuff on your skin.




References

A. L. Agero and V. M. Verallo-Rowell. A randomized double-blind controlled trial comparing extra virgin coconut oil with mineral oil as a moisturizer for mild to moderate xerosis. Dermatitis 2004, 15, 109.

J. C. DiNardo. Is mineral oil comedogenic? J Cosmet Dermatol 2005, 4, 2.

12 comments:

  1. A very helpful Part 2 :-) Thanks.

    ReplyDelete
  2. I always thought it caused pimples. I started avoiding it in makeup when my acne was bad in high school. Thanks for clearing that up! :)

    ReplyDelete
    Replies
    1. So did I, Dolly lied to me! *shakes fist*

      Delete
  3. All I could think was "poor bunnies" too hehe :) I love this post, informative as ever!!

    ReplyDelete
    Replies
    1. Thanks! Did you read about the earless bunny? I almost cried, the poor thing! :(

      Delete
  4. Thank you--it's great to see some sound sense (not to mention actual scientific facts) on mineral oil. With you in, ahem, fellowship in bringing illumination, enlightenment, and free open knowledge!

    ReplyDelete
  5. I think your link code to the 1st post has a glitch in it.

    ReplyDelete
    Replies
    1. Thanks for spotting that! It should be fixed now :)

      Delete
  6. Aren't some statements conflicting?

    'Mineral oil is an excellent occlusive, so yes, it does just sit on top of your skin - but it definitely moisturises!' - If it DEFINITELY moisturises, then by that logic, shouldn't it moisturise dry skin to make it less dry?

    'Of course, if you have dry skin to begin with, just putting mineral oil isn't going to work so well (if there's not enough water to begin with, there's not much water to keep in!).' - So it doesn't help dry skin? Meaning it doesn't moisturise?

    ReplyDelete
    Replies
    1. That's a good question - think of mineral oil as being like cling film for your skin. If you have a fresh piece of fruit and you wrap it up in cling film, it'll stay wet for longer because the film keeps the water in, but if you start off with a sultana and you wrap that in cling film, the sultana isn't going to get rehydrated, it'll just stay how it is. If you have a sultana and you put some water on it, and THEN wrap it in cling film, then the cling film will keep the water with the sultana and it'll plump up again, much faster than if you just add water to a sultana and leave it sitting open to the air. It's pretty much the same with skin - that's why a lot of moisturisers recommend that you apply them after a shower, so the moisturiser "cling film" has water to seal in :)

      Delete
    2. Thanks for the response! I personally am not a fan of petroleum by-products but that has more to do with me being eco-conscious rather than whether the products are ok for my skin or not :)

      Delete

Thanks for commenting! I read every single one :) No spam please.

Related Posts Plugin for WordPress, Blogger...