Know Your Product: Sunscreens

Sunscreens are so common that nearly everyone uses them at this point. They’re meant to shield your skin from the harmful UV rays of the sun and prevent skin cancer risks, excessive tanning or discolouration, and various other skin problems. Since sunscreens are so essential, the ingredients that go into them should ideally be extremely healthy. They should not be cause irritation or skin allergies, and should be able to withstand powerful UV radiation without losing their effectiveness or forming potentially harmful breakdown products. People can potentially inhale ingredients in sunscreen sprays and ingest some of the ingredients they apply to their lips, so ingredients must also not be harmful to lungs or internal organs. 

But do the ingredients that go into these products really adhere to the above criteria?

Use of Chemical Filters

Active ingredients in sunscreens come in two forms, mineral and chemical “filters”. Each of these filters use a different mechanism for protecting skin and maintaining stability in sunlight. 

The most common sunscreens on the market contain chemical filters, typically containing a combination of two to six of the following active ingredients: oxybenzone, avobenzone, octisalate, octocrylene, homosalate and octinoxate. But mineral sunscreens use something called zinc oxide and/or titanium dioxide, which aren’t as harmless as they sound.

Laboratory studies have indicated that some chemical UV filters may act like hormones once they’re in your body, and physicians report various sunscreen-related skin allergies, which raises important questions about consequences of frequent sunscreen application. 


Though there have been no clear scientific proof of the ingredients in sunscreen causing potential cancer risks (or something equally drastic), published studies suggest that several chemical filters interact with human sex or thyroid hormones and lead to various hormonal imbalances.

Among the nine most common chemicals used in sunscreens, the most worrisome is oxybenzone, added to nearly 65 percent of the non-mineral sunscreens that are in circulation. Oxybenzone can cause allergic skin reactions and can disrupt the production of estrogen in the body, leading to multiple health complications. Among adolescent boys, too much oxybenzone causes a reduction in testosterone production.

Other Chemicals

Other toxic active ingredients present in sunscreens include Octinoxate, Homosalate, Octisalate, and Octocrylene. In controlled amounts, they might not have any adverse effects, but in excess, they can deeply damage the outer coating of skin cells and inflame certain portions of it. Homosalate sometimes disrupts estrogen, androgen and progesterone production, which can lead to complications in genital growth, sexual drives, and so on.

Mineral sunscreens

Mineral sunscreens are made with zinc oxide and titanium dioxide, usually in the form of nanoparticles.

These particles don’t usually penetrate into the skin tissues, and hence, mineral sunscreens tend to fare better than chemical sunscreens in terms of it being healthier and safer. However, it is important that manufacturers use forms of minerals that are coated with inert chemicals to reduce photoactivity. If they don’t, users could suffer skin damage. Though, to date, no such problems have been reported.

Inactive ingredients

Sunscreens also contain something called “inactive ingredients”, which typically make up 50 to 70 percent of a sunscreen product. One ingredient in particular is a cause for concern: methylisothiazolinone, a preservative. Methylisothiazolinone is used alone or in mixtures with a related chemical preservative called methylchloroisothiazolinone, and is a skin sensitizer or allergen. Excessive exposure to this chemical can cause severe allergies, especially for adolescents and younger children. Therefore, checking the composition of this chemical or avoiding products that contain it is preferable.

Sunscreens can be extremely useful and indispensable, but can come with its own set of risks. So before you use it, its best to make sure you know every single ingredient that has gone into the said sunscreen and are certain that they are safe and healthy.

About the Author

Rohini Banerjee

Rohini Banerjee is a 23-year old freelance writer who is passionate about issues relating to gender, sex, and sexuality. She's also an advocate for mental health awareness, queer rights, and education, while balancing an abiding love for literature and popular culture.