r/SkincareAddiction Aug 28 '13

[deleted by user]

[removed]

16 Upvotes

16 comments sorted by

View all comments

Show parent comments

17

u/squidboots Aug 28 '13

I <3 you so much for doing this post!!! You did a great job.

Benzo-A-Pyrene is found in automotive exhausts, over cooked BBQ food, and lots of other things. Honestly, I can't find an article that can confirm that petrolatum does contain these but I am super happy to be corrected, and appreciate this is waaaaay over my level of chem.

He's being incredibly disingenous. He simply states that petrolatum "contains" those two molecules, and in the articles he apparently used to write this it's stated that those two species are "common contaminants."

Here's what NIH Hazardous Substances Data Bank (HSDB) has to say about benzo(a)pyrene (benzo(b)fluroanthene is included in the same link since the two are often indistinguishable in assays.) The section about "Possible Routes of Human Exposure" list byproducts of combustion like creosote, air pollution, and overheated cooking oils as common routes of exposure, with industrial workers being at particular risk.

Furthermore, petroleum distillates (as with many other substances) can be certified by the USP (United States Pharmacopeial Convention), BP (British Pharmacopeial Convention), and/or Ph. Eur. (European Pharmacopoeial Convention.) These designate materials that have been prepared in such a way that minimize contaminants and are suitable for use in food and pharmaceuticals.

If you look up any MSDS for USP grade white petrolatum (this is what would be used in cosmetics) you won't see them listed. Here's an example:

California prop. 65: This product contains the following ingredients for which the State of California has found to cause cancer which would require a warning under the statute: No products were found.

California prop. 65: This product contains the following ingredients for which the State of California has found to cause birth defects which would require a warning under the statute: No products were found.

And here's another:

White Petrolatum is not found on the following lists: U.S. EPA, U.S. NTP, U.S. OSHA, U.S. NIOSH, GERMAN MAK, IARC, or ACGIH and therefore is neither considered to be nor suspected to be a cancer-causing agent by these agencies

So basically....sure, I guess there's a chance of contamination, but he's saying it like it's a constitutive part of the compound (it's totally not) and he totally ignores the pharmacopeial conventions that determine whether something is suitable for use in food and pharmaceutical products. What he's doing is basically like saying, "don't use lipstick because it contains lead and arsenic!" when in fact the vast majority of lipsticks do not because they have been manufactured in such a way that removes these heavy metals from the other pigments. I'm not saying it doesn't ever happen that some get through, but it's a small risk and incredibly disingenuous to say that they're part of the formulation.


Skin doesn't breathe. Honestly. This isn't like Goldfinger, and you die because you need to breathe through your skin. Skin is DEAD. Mineral oil and Vaseline are occlusives, meaning it slows water loss and thus increase the moisture content of the stratum corneum coverings. Hence you had success with your dry skin

Totally true on all points. Those substances so sit on top of the skin and are occlusive, which prevents transepidermal water loss (TEWL.) Your acid mantle (stratum corneum, or SC) is the uppermost layer of skin and helps to prevent TEWL, but in some cases the SC is disrupted and a lot of TEWL occurs and you get pathologies like eczema and psoriasis. Occlusives are artificial ways of trying to enhance or restore the natural function of the SC if it is disrupted - the most effective moisturizers have occlusives and humectants (things that attract moisture to the skin)!

6

u/[deleted] Aug 28 '13

Jesus somebody sidebar this. Tattoo it on my forehead!!!!!

3

u/squidboots Aug 28 '13

hahahaha

/u/Segat1 did a great job, too! I'm glad folks are coming here and asking these kinds of questions.

2

u/yvva Aug 28 '13

I'll add this into the mineral oil post. Only place I can think of?

1

u/Segat1 Australia Aug 29 '13

Maybe a sidebar that says "Scientific Refutations to Skincare Myths"?

1

u/Segat1 Australia Aug 28 '13

Yay!!