Sunscreens are available in a seemingly endless array of sprays, lotions and creams, with sun protection factors (SPFs) that range from 15 to 100 and higher. Many promise waterproof or sweatproof formulas that last for hours. But consumers had no way of really knowing just how effective different sunscreens are – until recently.
At the end of 2012, the Food and Drug Administration (FDA) implemented new sunscreen labeling regulations. Products can no longer claim broad-spectrum protection unless manufacturers can prove their products provide adequate protection against UVA and UVB rays with an SPF of 15 or higher, based on established federal standards.
Additionally, manufacturers can no longer advertise their sunscreens as "waterproof" or "sweatproof." Instead, they may claim their products are "water-resistant" or "sweat-resistant," but they must clearly state how long those formulas provide that resistance for: 40 or 80 minutes.
Consumers may also notice fewer formulas promising astronomically high SPF ratings. The FDA has proposed limiting sunscreens to SPF 50+, but has yet to implement such a requirement. Wipes, towelettes, powders, body washes and shampoos promising protection from the sun's rays must also meet new protection standards, but they cannot be marketed as sunscreens without special approval from the FDA.
Lastly, the FDA says it is still evaluating the safety and efficacy of spray-based sunscreen formulas because they "are applied differently from other sunscreen dosage forms, such as lotions and sticks."
There are two types of skin-damaging ultraviolet (UV) rays: UVB and UVA rays. UVA rays are longer (320 to 400 nanometers) and penetrate the skin at deeper levels than UVB rays, causing long-term damage associated with signs of aging and skin cancer. According to the Skin Cancer Foundation, these rays are "present with relatively equal intensity during all daylight hours throughout the year, and can penetrate clouds and glass."
UVB rays, on the other hand, are shorter (290 to 320 nanometers) and are the main culprit for sunburns. Unlike UVA rays, the intensity of UVB rays varies by season, location and time of day. In the United States, UVB rays are most intense between the hours of 10 a.m. and 4 p.m., from April to October.
A product's ingredients are directly connected to its level of protection. The best formulas should contain broad-spectrum chemical or physical sunscreens or a combination of the two that block both UVA and UVB rays.
Physical sunscreens are made with minerals (titanium dioxide and zinc oxide) that form a natural, protective layer on the skin that blocks the sun's harmful rays. Chemical sunscreens (avobenzone, Mexoryl SX and Tinosorb) absorb UV rays.
It's important to note that some chemical sunscreens, including the commonly used oxybenzone, don't offer full protection because they can only block a portion of the UVA spectrum.
Experts have suggested that daily sunscreen usage can increase a person's risk of developing a vitamin D deficiency, because the sun is the most readily available source of this nutrient. However, dermatologists say you still get enough sun through sunscreen to produce vitamin D and sunscreen is necessary to reduce the risk of skin cancer. Ultimately, medical experts say this: Skin cancer is a proven threat -- and the only real way to reduce risk is to limit sun exposure by staying indoors, wearing protective clothing and using broad-spectrum sunscreen.
If you're concerned about a deficiency, speak to your doctor. Sunshine aside, Vitamin D is also available in supplements and certain foods. See our report on multivitamins for noteworthy options. In order to find the best sunscreen formulas, ConsumerSearch analyzes professional reviews from experts like Paula Begoun, ConsumerReports and Good Housekeeping magazine. Users reviews at MakeupAlley.com, TotalBeauty.com and Drugstore.com are also evaluated.