“Does Sunscreen Cause Cancer?”  The answer to this question, which seems rather farfetched, used to be quite simple.  “No, it does the opposite and protects you from skin cancer”, the answer used to go.  That is, until the recent news that multiple brands of sunscreen were found to have chemical contamination with benzene, a compound that is a known carcinogen.

Background

Ultraviolet radiation, or “UV radiation”, causes skin damage by damaging the DNA of the skin cells, leading to skin cancers and precancerous lesions.  It also has a profound effect on photo aging of the skin, leading to collagen loss and increased skin laxity.  Ultraviolet radiation comes in three types, UVA (which is associated with photo aging and pigmentation), UVB (which causes DNA damage and skin cancers), and UVC (which is absorbed by the ozone layer).  Of these, UVA freely passes through he ozone layer and UVB is filtered by the ozone layer, but both remain the primary targets of sunscreens.

The entire rationale for using sunscreen is to prevent cancer, as it interferes with the ultraviolet radiation’s ability to penetrate the cells and cause DNA damage.  Ideally, the answer to “Does sunscreen cause cancer?” is simply “No”.

Physical Sunscreen

Sunscreen comes in two primary forms: physical and chemical.  The physical blocks are based on zinc oxide and titanium oxide, and are based on “physically” blocking the sun’s UV rays from your skin by reflecting and scattering the radiation.  The heavy metals interrupt the flow of cancer causing ultraviolet radiation from getting to your skin by making the radiation go elsewhere.

Chemical Sunscreen

The chemical sunscreens (also known as “organic sunscreens”) are based on absorbing the ultraviolet radiation.  Chemically speaking, they have the ability to absorb UV radiation and release it as a lower energy form.  Each chemical sunscreen absorbs a slightly different wavelength.  This can aim the organic sunscreens squarely at UVA, UVB, or even UVC.  A mixture of compounds is commonly used to augment the physical component of the sunscreen.

What is Benzene?

Benzene is a very stable chemical molecule that has a “pool” of electrons above and below the plane of the molecule, giving it the ability to absorb photons of varying radiation depending on how the benzene is “dressed”, or what is attached to it.  It is made purely of hydrogen and carbon, and is found in gasoline and is involved in many common chemical reactions due to its unique structure, which is shown here.

benzene chemical structure

Benzene is a known carcinogen, and its exposure has been associated with hematologic malignancies like leukemia, and should be avoided.  And it should definitely not be rubbed into the face and body.

Benzene contaminating multiple batches of sunscreen is the reason that it is possible now that sunscreen causes cancer.  Luckily, it is not “all” or even “most” of them, it is just a few that we know of now.

 

Benzene in Sunscreen

Where did the benzene come from?  Was it contamination during the production of the organic sunscreen?  Was it from another source?  It is not known, and it honestly is not very important.  We know that certain lots of sunscreen contain this, and there is no “safe” level of benzene that you want to be exposed to. Benzene causes cancer in all concentrations, so benzene in sunscreen makes sunscreen cause cancer.

I have provided a gallery of pictures of sunscreen chemical compounds below, and want to point out that the chemical structure of benzene appears in all of these.  This is not by chance, as the unique ability of benzene to absorb photons of energy is what makes its derivatives great UV blocking agents.

sunscreen benzene

Commonly used organic sunscreens with the benzene rings highlighted

Which Sunscreen Should You Use?

This is a very complicated question, as the independent lab that tested the sunscreens actually tested 294 samples from 69 brands of sunscreen, and of those, 78 had detectable benzene levels.  I would look into the original document (https://s3.documentcloud.org/documents/21010417/valisure-citizen-petition-on-benzene-in-sunscreen-and-after-sun-care-products-v97.pdf) that lists all of the sunscreens tested, and get that answer yourself.  I would interpret this list carefully, and any of them that have benzene contamination should be flagged as a “sunscreen that causes cancer”.

At Nuance Facial Plastics, we have EltaMD’s UV Clear and UV Daily in stock, neither of which are listed as being contaminated with benzene.  If you are not going to use one of these, then a way to minimize benzene exposure would be using a pure physical block, based on zinc oxide and titanium oxide, without the chemical sunscreens that are more likely to be contaminated with benzene.

To check out the latest information about the voluntary recall of the Johnson & Johnson products, please check out the FDA’s web site: https://www.fda.gov/safety/recalls-market-withdrawals-safety-alerts/johnson-johnson-consumer-inc-issues-voluntary-recall-specific-neutrogenar-and-aveenor-aerosol

Disclaimer

Yes, I understand that chemicals are more complicated than this oversimplification of finding benzene (or aromatic rings) in sunscreen components.  This post was not meant to be an in depth class in organic chemistry, but rather a little background for the lay reader as to what benzene is, and what organic sunscreen components do to block ultraviolet radiation.  It is also meant to show people that their sunscreen was not tainted by gasoline, but rather by a chemical similar to an active ingredient in the sunscreen.