From pool parties to picnics, hiking to biking: everyone loves spending time outdoors on a sunny day. But too much sun can be harmful, and it’s crucial to make sure that when you spend time in the sun, you are protecting your skin.
A suntan results from an activation of the body’s natural defense mechanism against damaging ultraviolet (UV) sun rays. Excessive exposure to UV light can overwhelm the body’s defenses and result in sunburn.
Ultraviolet A (UVA) and Ultraviolet B (UVB) are the two types of solar radiation that can harm your skin. UVB is responsible for sunburns and is partially blocked by the ozone layer. UVA is not absorbed by the ozone and penetrates the skin deeper than UVB. Neither type of UV ray is safe.
Sunburn Treatment & Remedy Tips
If sunburned, follow these steps to treat your symptoms:
- Decrease inflammation using a nonsteroidal anti-inflammatory drug (NSAID). These include ibuprofen, naproxen, or aspirin.
- Apply moisturizing cream to relieve discomfort.
- Take a cool shower or bath.
- Wear dry bandages if blisters are visible to help prevent infection.
- Wear loose cotton clothing.
- Prevent further exposure to the sun.
- Do not use products that have benzocaine or lidocaine, which might make the burn worse.
Sunscreens help to protect against sunburn by blocking the sun’s harmful ultraviolet rays. Excessive exposure to the sun’s UV rays (as well as UV rays from tanning beds) increases your risk for developing skin cancer, regardless of your age, gender, or race. Approximately one in five Americans will develop skin cancer in their lifetime.
How to Read a Sunscreen Label
Most sunscreens products are available for purchase over-the-counter (OTC) and are regulated under the FDA monograph system, which means that information on sunscreen labels is approved by the FDA. The Monograph outlines the requirements for which active ingredients can be used, allowable concentrations, dosage forms, and other specifications.
Sun Protection Factor (SPF)
Sun Protection Factor (SPF), is a measure of how well a sunscreen protects your skin from the kind of radiation (UVB rays) that causes sunburn, damages skin, and may contribute to skin cancer. The higher the SPF, the more protection the sunscreen will provide against UVB rays. SPF does not measure protection from UVA rays.
If your skin would normally burn after 10 minutes in the sun, applying an SPF 30 sunscreen would allow you to stay in the sun without burning for approximately 300 minutes (a factor of 30 times longer). This is a rough estimate that depends on skin type, intensity of sunlight, and amount of sunscreen used. Experts recommend that you use a minimum SPF 30 sunscreen, apply the proper amount (2mg/cm2 of skin, or about one shot glass—1 ounce—for full body coverage), and reapply every 2 hours.
The SPF (Sun Protection Factor) scale is not linear:
- SPF 15 blocks 93% of UVB rays
- SPF 30 blocks 97% of UVB rays
- SPF 50 blocks 98% of UVB rays
Physical vs. Chemical Sunscreens
There are two types of sunscreens: chemical and physical. Physical sunscreens protect your skin from the sun by deflecting or blocking the sun’s rays. Chemical sunscreens work by absorbing the sun’s rays. Some chemical filters can scatter the sun’s rays, but still mostly just absorb them.
Broad Spectrum Sunscreen
Many sunscreens combine active ingredients to provide “broad spectrum” protection—meaning protection against both UVA and UVB radiation.
UVA rays can cause premature aging of your skin (e.g., wrinkling and age spots). UVB rays can cause your skin to burn. Excessive exposure to UVA or UVB rays can cause skin cancer.
Water Resistant Sunscreen
A “water resistant” sunscreen retains its stated SPF value after a certain time in water or while sweating. FDA only allows the claims ‘Water Resistant (40 min)’ or ‘Very Water Resistant (80 min)’ to be used on sunscreens sold in the United States and does not allow sunscreen products to claim that they are “water proof.”
Active Ingredients and Allowed Levels in Sunscreen Products
There are two types of sunscreen active ingredients: organic and inorganic. Organic active ingredients, such as octyl methoxycinnamate or oxybenzone, work by absorbing UV radiation. Inorganic active ingredients, like zinc oxide or titanium dioxide, work by either reflecting or scattering UV radiation. Here are some common active ingredients and their maximum allowed levels in sunscreen products:
- Aminobenzoic acid (PABA, ≤15%)
- Avobenzone (≤3%)
- Cinoxate (≤3%)
- Dioxybenzone (≤3%)
- Ecamsule (≤3%)
- Homosalate (≤15%)
- Menthyl anthranilate (≤5%)
- Octocrylene (≤10%)
- Octyl methoxycinnamate (a.k.a. octinoxate) (≤7.5%)
- Octyl salicylate (a.k.a. octisalate) (≤5%)
- Oxybenzone (≤6%)
- Padimate O (≤6%)
- Phenylbenzimidazole sulfonic acid (ensulizole, ≤4%)
- Sulisobenzone (≤10%)
- Titanium dioxide (≤25%)
- Trolamine salicylate (≤12%)
- Zinc oxide (≤25%)