Sunscreen Basics
Active ingredients in sunscreens should absorb, reflect, or scatter ultraviolet (UV) radiation. For years, manufacturers created sunscreens that were only effective at screening out UVB radiation (known to cause sunburn and lead to skin cancer). More recently, manufacturers have worked to create sunscreens that will protect your skin from both UVA and UVB radiation (realizing that UVA radiation is also harmful). All sunscreens provide UVB protection, but only some protect against UVA rays.
The ideal sunscreen should:
- Block both UVA and UVB rays
- Have active ingredients that do not break down in the sun
- Contain active and inactive ingredients proven to be safe
When picking a sunscreen look for:
- Zinc oxide or titanium dioxide
- SPF of 30 or higher
- The Skin Cancer Foundation’s Seal of Recommendation
When picking a sunscreen avoid:
- Oxybenzone
- Sunscreens with fragrance
- Sunscreen sprays, powders, and bug repellants
Sunscreen can only provide partial protection against harmful effects of the sun. Limiting sun exposure and wearing protective clothing, including a wide-brimmed hat, are even more important for protecting your skin from cancer and premature aging. Be extra careful about sun exposure during 10 am and 4 pm when the sun’s rays are most intense. Apply sunscreen generously 30 minutes before going outside and reapply it often – at least every 2 hours.
Sunscreen should not be neglected on overcast days, as 70-80 percent of the sun’s rays go through clouds and fog. In addition, UVR levels rise ten to twenty percent for every 1000 feet of altitude, and reflection from sand, water, snow or concrete magnifies their effects by up to 80 percent.
