Sunscreen FAQs

When should I use a sunscreen?

Generally, if you’re going to be exposed to the sun for over 20 minutes, it’s a good idea to use a sunscreen—whether it’s a sunny day or cloudy day. Many people don’t realize that 80 percent of the sun’s ultraviolet rays can filter through the clouds.

How much sunscreen should I use?

Apply sunscreen to your face, ears, hands and arms, and make sure to coat the skin well. Remember, a missed spot could mean a patchy, painful sunburn. Lips also can get sunburned, so a lip balm with sunscreen is advisable.

As a rule, it’s best to apply sunscreen to dry skin 30 minutes prior to heading out into the sun. Also, reapply sunscreen every 2 hours; moreso after excessive sweating or swimming.

Is there a particular type of sunscreen that works best?

The type of sunscreen you use is a matter of personal preference. Sunscreens are available in many forms including ointments, creams, gels, sprays, pads, and lotions. Most dermatologists recommend a sunscreen with an SPF 30 or higher. Broad-spectrum formulas are ideal, as they protect against the full range of ultra-violet sunlight. Waterproof sunscreens are ideal for most outdoor situations.

Ingredients that provide broad-spectrum protection include benzophenones (oxybenzone), cinnamates (octylmethyl cinnamate and cinoxate), sulisobenzone, salicylates, titanium dioxide, zinc oxide, and avobenzone (Parsol 1789).

Does a sunscreen protect me from both UVA and UVB (ultraviolet) rays?

Not necessarily. UVB rays are the sun’s burning rays, and are the primary cause of sunburn and skin cancer. UVA rays penetrate deeper into the dermis, or base layer of the skin. They damage the cellular makeup of the skin, contributing to skin discoloration, wrinkles and other signs of aging. They also contribute to sunburns and skin cancer. UVA rays are present for longer portions of the day, every day of the year, and can penetrate glass.

Since PABA and PABA esters only protect against UVB light, check for a broad-spectrum sunscreen that also screens UVA rays. Ingredients like benzophenones, oxybenzone, sulisobenzone, titanium dioxide, zinc oxide, and avobenzone (Parsol 1789), extend the coverage beyond the UVB range and into the UVA range, helping to make sunscreens broad-spectrum.

Mexoryl SX is an ingredient that was approved by the FDA in 2006 to safeguard the skin against UVA sun rays, and is in fact the first sun filter approved by the FDA in 18 years. Anthelios SX, which utilizes Meroxyl and is made by La-Roche Posay, has been a popular broad spectrum sunblock in Europe for years, and this popularity has transfered to North America since it first became available in late 2006.

What is an SPF?

SPF means Sun Protection Factor, and sunscreens are rated or classified by the strength of their SPF. SPFs range from 2 up to 65. These numbers refer to the product’s ability to deflect the sun’s burning (UVB) rays.

The sunscreen SPF rating is calculated by analyzing the amount of time needed to produce sunburns on protected skin versus unprotected skin. For example, if a sunscreen is rated SPF 2 and a fair-skinned person who would normally turn red after ten minutes of exposure in the sun uses it, it would take twenty minutes of exposure for the skin to turn red. A sunscreen with an SPF of 15 would allow that person to multiply that initial burning time by 15, which means it would take 15 times longer to burn, or 150 minutes. However, it is safest to use the strongest possible SPF rating, and to reapply frequently.

Does the SPF tell how well a sunscreen protects against UVA or UVB rays?

The SPF number on sunscreens only reflects the product’s screening ability for UVB rays. At present, there is no FDA-approved rating system that identifies UVA protection. Scientists are working to create a standardized testing system to measure UVA protection.

What is the difference between a sunscreen and a sunblock?

Since sunscreens can now either chemically absorb UV rays, or deflect them, the term sunblock is rarely used.

It’s important to find a sunscreen that offers both UVA and UVB (broad spectrum) protection and includes ingredients such as benzophenones, oxybenzone, sulisobenzone, titanium dioxide, zinc oxide, and avobenzone (Parsol 1789).