What's the risk? – Sunscreen

In this series we look at common products and ingredients we use throughout the spring and summer to explore their safety and toxicity. In this post, we take a look at sunscreen ingredients.

What are the different types of sunscreens?

Sunscreen products help protect our skin from the sun's damaging ultraviolet rays. There are two types of sun rays, UVA and UVB, known to damage skin and cause skin cancers over time.
To combat the sun exposure, scientists developed lotions, sprays, oils, creams, gels, butters, pastes, ointments, and sticks that contain active ingredients that can help protect our skin from the damaging UVA and UVB rays.
Two types of active ingredients can provide broad-spectrum sunscreen coverage:

  • Mineral-based sunscreen.
  • Synthetic-based sunscreens.

What are the active ingredients found in sunscreens?

Mineral-based sunscreens use titanium dioxidezinc oxide, or these ingredients in combination to provide sun protection. 
Synthetic-based sunscreen use cinoxate, dioxybenzone, ensulizole, homosalate, meradimate, octinoxate, octisalate, octocrylene, padimate O, sulisobenzone, oxybenzone, avobenzone, or some combination of these ingredients to provide sun protection.   

Are sunscreens regulated?

The U.S. Food and Drug Administration (FDA) regulates sunscreens to ensure they meet safety and efficacy standards.  

How are mineral-based sunscreens different than synthetically-derived sunscreens?

While mineral and synthetically-derived sunscreens provide sun protection, our bodies absorb and process them differently.   
Our skin is an exposure route, as discussed in prior posts. While our skin generally serves as a barrier to prevent the entry of harmful pathogens and chemicals, it can sometimes absorb and process topically applied ingredients.
Mineral-based sunscreens contain active ingredients that researchers have repeatedly studied. Based on the scientific consensus, it has been determined that these sunscreens do not pose harm to human health. So, mineral-based sunscreens received the designation as generally recognized as safe and effective (GRASE) when used as intended and do not require any further safety evaluations (1,2).   
Our skin can absorb some synthetically-derived sunscreen ingredients, and these ingredients can make their way throughout our bodies. 
Research shows some of the active ingredients can be found in our bloodstream. Since there is no scientific consensus on these ingredients, scientists are researching what, if any, impact this has on our health before issuing a final safety determination.  

What about recent voluntary sunscreen product recalls?

Recently, some sunscreen and sun product manufacturers have issued product recalls in an abundance of caution because a laboratory found the presence of an ingredient called benzene in some aerosol sunscreen and sun products. 
Regulators have determined that when unavoidable, a therapeutically necessary product can contain up to 2 parts per million (ppm) (parts per million explained) of benzene. However, some products exceeded that threshold, while other products did not.
Since benzene appears to be a contaminant, meaning manufacturers did not intentionally add the ingredient to the product, some companies have decided to recall the sunscreen. 
While the sunscreen products have not been shown to cause harm, the companies are choosing to err on the side of extreme caution.  

Are they safe?

While research is underway around synthetic-based sunscreens, the FDA still recommends people use sunscreens that contain these synthetic active ingredients in conjunction with other sun-protective practices to protect our skin.   
As we've discussed in prior posts, the presence of a chemical doesn't necessarily mean it's causing harm or that our bodies cannot effectively process and eliminate the ingredients. We do know that without sunscreen, we can cause severe damage to our skin that can lead to burns and, over time, potentially skin cancer
Mineral-based sunscreen is considered safe by the FDA and is known to provide robust sun protection without any known side effects. 

Does sunscreen expire? 

Yes, most sunscreens will have an expiration date on the bottle. 

If it does not have an expiration, look for a manufactured date. If the manufactured date is within the last three years, you can safely use the product. If it was manufactured more than three years prior, it should not be used (1).  

Does it matter how sunscreen is stored?

Yes, keeping sunscreen out of direct sunlight can help it remain safe and effective longer.  

How does SPF work? 

Many people think the higher SPF, the longer you can spend in the sun; that is not how SPF works. 
SPF relates to the sunscreen's ability to block UVA and UVB sun rays. The higher the SPF, the greater protection you get from the sun.
For example, if your skin is darker, you may only need SPF 15 reapplied every 2 hours to protect your skin from sunburns. If your skin is lighter, you may need a sunscreen above SPF 30 reapplied every 2 hours to protect your skin from sunburns (1).
Regardless of the SPF level, you should reapply sunscreen according to the packaging for the sunscreen to remain effective, usually around every 2 hours, depending on your activity level (1).  

Is sunscreen waterproof? 

Sunscreen can be water-resistant for a specific amount of time, but it isn't waterproof. You still need to reapply sunscreen regularly to ensure you're getting the needed protection (1).

Is sunscreen safe for children and babies? 

Sunscreen is safe and recommended for children over the age of 6-months. It's also recommended that children wear sun-protective clothing with UPF 50+ properties to help prevent sunburns.
For babies under 6-months of age, talk with your pediatrician before using sunscreens. Clothing with UPF 50+ is a safe option for this age group in conjunction with keeping young babies out of direct sunlight.   

What's the risk?

Scientists are currently researching potential hazards that may be associated with sunscreen ingredients absorbing into our bodies. However, no adverse health effects have been found at the time of publication. 
The risks of not using sunscreen far outweigh the risks of using sunscreen. We know exposure to UVA and UVB rays can increase your risk of developing
  • Skin cancers, including basal cell carcinoma, squamous cell carcinoma, melanoma, and more.
  • Premature skin aging.
  • Cataracts. 
According to The Skin Cancer Foundation,
  • 1 in 5 Americans will develop skin cancer by the age of 70.
  • More than 2 people die of skin cancer in the U.S. every hour.
  • Having 5 or more sunburns doubles our risk for melanoma.
  • More people are diagnosed with skin cancer each year in the U.S. than all other cancers combined.
  • About 90 percent of nonmelanoma skin cancers are associated with exposure to ultraviolet (UV) radiation from the sun. 
We know using sunscreen regularly and as directed can help decrease our risk of developing adverse health outcomes from repeated sun exposure and sunburns. 
Taking these statistics into consideration, we can easily see how the risks of repeated sun exposure and sunburns far our weights the risks of a potential adverse reaction to sunscreen ingredients.

The good news.  

While we're still learning more about the active ingredients in sunscreen, we do know that there are many safe options for sun protection. By learning more about these ingredients, scientists can continue to develop new and better products to protect us from damaging sun rays.

If you have any questions about foods and ingredients, please reach out to us on Twitter, send us an email, or submit your idea to us at go.msu.edu/cris-idea.  

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