Can I Keep Sunscreen in the Car?
The short answer? It's not ideal. Here's what dermatologists want you to know about proper sunscreen storage – and a smarter solution for on-the-go protection...
The Science: What Happens to SUNSCREEN IN THE CAR
Your car's interior can reach temperatures of 120°F or higher on a sunny day – even when it's only 80°F outside. This intense heat can break down the active ingredients in sunscreen, making its UV protection significantly less effective. Extreme temperatures can also cause sunscreen formulations to separate or degrade.
The FDA recommends storing sunscreen at room temperature, ideally below 77°F., which means you're not getting the SPF protection listed on the bottle.
Compromised Sunscreen is Unreliable
When sunscreen degrades, it doesn't just become less effective – it can become completely unreliable. The chemical and physical UV filters that protect your skin from harmful UVA and UVB rays lose their potency when exposed to extreme temperatures. You might apply what you think is adequate protection, only to end up with an unexpected burn.
This is particularly concerning for those who spend significant time outdoors. Whether you're playing pickleball, sailing or simply walking the dog, compromised sun protection puts you at risk for immediate damage (sunburn) and long-term consequences (premature aging and skin cancer risk).
If You Must: Heat-Resistant Sunscreen Options
If keeping backup sun protection in your car is unavoidable, consider these more stable options:
- Mineral (Physical) Sunscreens. Zinc oxide and titanium dioxide are generally more heat-stable than chemical filters. These physical blockers sit on top of the skin and are less likely to break down at high temperatures.
- Powder Sunscreens. Dry formulations without water content are inherently more stable in heat. They're not great for initial application, but they work well for touch-ups over makeup or on-the-go.
- Stick Formulations. While they may soften in heat, stick sunscreens often maintain their protective properties better than lotions. Look for those in sturdy packaging that won't leak if they warm up.
- Higher SPF Options. If you must store sunscreen in fluctuating temperatures, consider starting with a higher SPF (like 50+) to account for potential degradation – though this isn't a perfect solution.
Remember: even "heat-resistant" options have limits, and no sunscreen performs optimally after extended exposure to extreme temperatures.
Storage alternatives: Avoid the car
The ideal storage spots maintain consistent, moderate temperatures. Consider:
- At Home: A bathroom cabinet or bedroom drawer works well, away from windows and heat sources.
- At Work: Your desk drawer or office refrigerator (yes, cool storage is fine – just not freezing).
- In Your Bag: A purse, gym bag, or tennis tote that comes with you, rather than staying in the car.
Frequently Asked Questions
How hot does my car actually get inside?
Even on a 70°F day, your car's interior can reach 104°F within 30 minutes. On 90°F days, temperatures can soar to 138°F or higher – well beyond the recommended storage temperature for most skincare products.
Can I tell if my sunscreen has been damaged by heat?
Sometimes. Look for separation (oil floating on top), changes in texture, unusual smell or altered color. However, sunscreen can lose effectiveness without visible signs, which is why proper storage is crucial.
What about leaving sunscreen in my tennis bag or beach bag?
This is generally better than car storage since bags typically experience less extreme temperature swings. However, avoid leaving bags in direct sunlight for extended periods.
Is expired sunscreen better than no sunscreen?
Yes, but it's unreliable. For consistent coverage, combine fresh sunscreen with UPF clothing that doesn't degrade over time.
Can I store sunscreen in a cooler in my car?
A well-insulated cooler with ice packs can work for short trips, but it's not practical for permanent storage. The ice will melt, and you'll still face temperature fluctuations.
How long does sunscreen last at room temperature?
Most sunscreens maintain their effectiveness for 2-3 years when stored properly at room temperature (below 77°F) and away from direct sunlight.
What's the best backup sun protection for my car?
Consider keeping a lightweight long-sleeve UPF 50 shirt or sun hat in your car. Effortless sun protection that won't be impacted by temperatures.
Ready to upgrade your sun protection routine? Explore JOJU's collection of lab-certified UPF 50+ apparel designed for tennis, boating, and everything after. Because the best sunscreen is the one you're already wearing.
