Is it Safe to Store Sunscreen in the Car?

Sunscreen is one tool in your arsenal to prevent UV-related skin damage. Like all drugs and medication, sunscreen must be stored properly to ensure it remains safe and effective for use. Whether you opt for spray-on, roll-on, cream, lotion, stick, or gel, it's best not to store sunscreen in the car. Read on to discover why.

Normal Chemical Breakdown When You Store Sunscreen in the Car

Sunscreen contains active and inactive ingredients that can break down over time. The U.S. Food and Drug Administration (FDA) regulates sunscreen as an over-the-counter drug and ensures that the components in FDA-approved sunscreen products remain stable for at least three years. If you have a sunscreen that is more than three years old, and there is no expiration date on the bottle, you can assume there has been some degradation of certain key ingredients in the sunscreen. In that case, you should no longer rely on it to protect yourself from sunburn and other damage to the skin. 

Heat Accelerates Breakdown

The standard three-year shelf life only applies if you store your sunscreen in dry, cool conditions. When the sun is shining, the temperature in your car can rise sharply and quickly. According to the National Weather Service, on a hot day, your car's dark dashboard or seat can reach temperatures ranging from 180 to 200 degrees Fahrenheit.  Hot car research conducted at the Stanford University School of Medicine demonstrates that even on relatively cool days, your car's interior can become dangerously hot if the sun is shining through the car windows. Exposure to such heat can accelerate the breakdown of your sunscreen's active components. 

The Effect on Your Skin

Sunscreen not kept cool and dry can undergo chemical and physical changes that affect the skin. According to Dr. Alik Vij, director of the dermatology residency program at the Cleveland Clinic, a breakdown of your sunscreen's components can lead to or exacerbate certain skin conditions, including rashes, acne, and contact dermatitis. 

Mess and Waste

Beware of aerosol sprays. High temperatures can cause a dangerous build-up of pressure in aerosol cans. If you leave a spray-on sunscreen in your car, the car's hot interior can cause the cap to blow off or the canister to crack open. Then, you'll be left with a mess.

Lotions, creams, sticks, and gels can melt and leak when you store sunscreen in the car. Here, too, you risk ruining your car's upholstery and any other items you have stored in your car. 

Tips for Safer Storage

If you rely on the SPF in sunscreen to protect you from sunburn, skin cancer, skin damage, and premature aging of the skin, it's best to take your bottle of sunscreen with you when you leave your car. If you do keep sunscreen in the car, do what you can to prevent overheating.

• Park your car in the shade.
• Wrap the bottle, tube or aerosol can in a cool towel.
• Keep your sunscreen in a cooler or insulated bag. 

Changes Worth Noting

Before you apply your sunscreen, make note of its color and consistency. If it looks or feels strange, its protective components may have broken down and lost their ability to protect you. If you have any reason to doubt your sunscreen's efficacy, the American Academy of Dermatology Association (AAD) recommends tossing the bottle and buying a new one. 

A Better Alternative

Instead of storing sunscreen in your car for spontaneous trips to the park, beach, or nature trail, find other ways to protect yourself from UV exposure. Keep a bag of lightweight, UV-resistant clothing in the corner of your trunk. Include a long-sleeve shirt, long pants, a wide-brimmed hat, and wrap-around sunglasses, all of which will provide vital protection from the sun. 

Don't Store Sunscreen in the Car

Sunscreen can be highly protective against sunburn, skin damage, and skin cancer, but only if it is properly applied and stored between uses. Don't trust the sunscreen that's been baking in your glove compartment. Instead, take other measures to protect yourself. Contact us at Little Leaves to learn more about safeguarding your skin with our outstanding line of sun-protective clothing.