How to Tell if Your Sunscreen's Legit

Wait - you might say - aren’t there responsible scientists testing all these sunscreens? Yes, but that doesn’t mean your bottle is telling you the whole truth. Here’s what to look for on the label.

1. Does your sunscreen protect against sunburn- and cancer-causing UVB rays?
If it doesn’t, it’s probably not allowed to be called “sunscreen.” Anything with an SPF number on the bottle contains ingredients that shield against UVB. SPF 15 buys you 15 times more sun exposure before you burn - but the catch is, it only stays effective on skin for about 2 hours. SPF 15 screens out 93 percent of UVB rays; SPF 30, 97 percent; and SPF 50, 98 percent.

2. Does it protect against aging and cancer-causing UVA rays?
Here’s where things get tricky. In the US, there are currently no legal guidelines for UVA protection on sunscreen labels. “Broad-spectrum” is a term used by many manufacturers to denote UVA & UVB protection, but it’s not regulated - and it doesn’t specify how much UVA protection you’re getting. What's more, there are two types of UVA wavelengths: UVA1 and UVA2. Your sunscreen should protect against both.

3. Does it contain UVA-protective ingredients?
Of the FDA-approved sunscreen ingredients, only about half protect against UVA at all. And only zinc oxide protects against the full range of UVA1 and UVA2; the rest should be combined with complementary ingredient to hit all the wavelengths. Here’s a chart from the Skin Cancer Foundation:

4. How effective are those UVA blockers?
The FDA has proposed new guidelines to measure effectiveness of UVA sunscreens, but the regulations remain in limbo. However, there are UVA protection scales used in other countries, and you might see them on products sold stateside. (Just remember, no agency in the United States is regulating these claims.)

The PA(+) rating system was developed in Japan and is used throughout Asia. You'll find PA ratings on brands like Shiseido, AmorePacific, 3LAB, Elizabeth Arden and Stri-Vectin. Here's what those ratings mean:

PA+: some UVA protection
PA++: moderate UVA protection
PA+++: high UVA protection

Shiseido and Elizabeth Arden sunscreens with PA ratings

The Boots 5-star rating system was developed by the British cosmetics company and is used in the UK and Ireland. One star signifies minimal UVA protection; five stars is the most protective.

In the European Union, the Persistent Pigment Darkening (PPD) method is used to measure UVA protection. PPD numbers mirror SPF: a 15 affords a person 15 times longer exposure. A PPD rating above 15 is considered ideal protection.

European sunscreens also get a UVA seal if they provide UVA protection that’s at least one-third the SPF. So if the SPF is 30, the UVA seal lets consumers know the PPD rating is at least 10 or higher.

In the US, the independent nonprofit Skin Cancer Foundation has adopted new standards for its sunscreen Seal of Recommendation. By May 2012, all sunscreens with the seal must have a PPD of 10 or higher. (Currently, the seal is awarded to any product with an SPF over 15.)

5. Is it chemical or physical?
Chemical sunscreens rely on a chemical reaction to block UV; physical sunblocks create a barrier between rays and skin. Titanium dioxide and zinc oxide are physical filters; almost every other sunscreen ingredient is chemical. Both types can provide broad-spectrum protection, though some people are sensitive to chemical formulas.

6. Is your sunscreen waterproof?
Trick question. There is no truly waterproof sunscreen, and even though you might see the word “waterproof” on labels, its use is unregulated. The FDA currently approves sunscreens as “water resistant” (40 minutes of activity in water) or “very water resistant” (80 minutes of activity). Towel-drying isn’t included in the test, so assume that toweling off wipes away most of your protection.

7. Does it contain vitamin A?
Retinyl palmitate is the form of vitamin A often added to sunscreens as an inactive, antiaging ingredient. But anyone who’s used Retin-A or a similar treatment knows what happens when vitamin A and sun mix (ouch). Though there’s no consensus yet, a report by the Environmental Working Group has raised red flags about retinyl palmitate’s potential to cause cancer in animals - so you might choose to avoid it.