Natural and Chemical Sunblocks Battle to Protect Your Skin

— -- Jessica Alba is in the hot seat recently, fighting back amidst controversy over the effectiveness of her company’s SPF 30 sunscreen lotion.

The criticism began earlier this week after parents weighed in online claiming the product is ineffective.

“It was like we used baby oil,” one mom posted in a review on Amazon.com.

“My daughter’s back looked like a tomato and even blistered in one spot,” wrote another.

Alba, 34, and her Honest Company co-founder Chris Gavigan are defending their product, explaining hers is one of the many so-called natural sunscreens on the market and insisting the sunscreen has gone through extensive third-party testing and passed all requirements.

"We develop and use Honest Sunscreen to protect our own children – Honor, Haven, Luke, Evie, and Poppy – at the park, in the pool, outside, every day,” they wrote in a letter on their website, adding that they “take sun protection seriously."

But the pictures being posted of the sunburns are reigniting a heated debate during the peak of summer: Do mineral-based sunscreens work differently than sunscreens that use chemicals?

Mineral-based sunscreens are often zinc or titanium based creating a barrier between the sun and your skin, while chemical-based sunscreens use substances like oxy or avobenzone to penetrate the skin and absorb the sun’s rays.

Consumer Reports did not test the Honest Company’s product, but previously tested five other natural sunscreens just last month where zinc oxide and/or titanium dioxide are the active ingredients. The magazine concluded mineral-based sunscreens are less likely to “offer skin the complete protection it needs.”

“One of the reasons why mineral sunscreens may not perform as well as the ones with chemicals is because the mineral particles form an uneven surface on your skin and you may not be getting good coverage,” Trisha Calvo, Consumer Reports’ Deputy Editor of Health and Food, told ABC News.

But most dermatologists agree that any sunscreen is better than none.

“Sunscreen is really important and you need to use it every day all year round, even on cloudy days, no matter what your skin type is,” said Dr. Doris Day, a member of the American Academy of Dermatology.

The American Academy of Dermatology itself is not taking a side in this debate, but it does say “always recommends a broad-spectrum, water- resistant sunscreen with an SPF of 30 or higher.”