I’m usually quite proud of my Irish ancestry, but one unfortunate vestige of that heritage is pasty white skin that sunburns quite easily. When my mother was pregnant with me and my twin brother, the doctors discovered a large melanoma on her leg which required immediate surgery. Fortunately everyone turned out just fine, but my family history and skin color certainly put me at higher risk of developing melanoma and other skin cancers. In fact, studies have shown that getting painful blistering sunburns during childhood is a major risk factor for melanomas, squamous cell carcinomas and basal cell carcinomas later in life. This is why it’s up to parents to protect their children from the sun’s harmful effects.

What are the essentials for sun protection? For infants under 6 months of age, the American Academy of Pediatrics doesn’t recommend any direct sun exposure, as their skin is especially pale and vulnerable. For most children and adults, a combination of sunscreens, proper clothes, and avoidance of peak times from 10am-4 PM (or following your local UV Index) are the major ways to avoid damage.

How effective are clothes? These should be a first line of defence for all ages, but a plain white t-shirt only has a Sunburn Protection Factor of 7, so you could still burn quite easily through this. Most other clothes, if thicker and darker, would offer a more protective SPF 15 or higher. But I still know all too painfully well that even a dark t-shirt won’t be enough if I’m out all day swimming and playing outside.

This is when sunscreens come in handy. A good sunscreen has been shown to decrease risk for skin cancers, most impressively with squamous cell carcinomas. One Australian study showed a 40% decrease in these cancers when using a broad spectrum SPF-16 sunscreen. The evidence for protection against the much deadlier melanomas actually isn’t so strong, with the best study published in 2010 in the Journal of Clinical Oncology. This randomized controlled trial followed 1,600 persons over 10 years in Australia, a region with the world’s highest rates of skin cancers. Those who routinely used sunscreen had a 73% reduction in invasive melanoma, although the accompanying editorial questions its statistical significance. Still, I agree with their conclusion that, “the question of its efficacy with respect to melanoma prevention should no longer deter scientists or clinicians from recommending sunscreen use…In addition to sunscreen use, excess exposure to ultraviolet rays should be avoided, clothing should be used to shield skin from the sun, and sun-safe environments should be used for outdoor recreation. In addition, sunscreen use should be paired with regular self-examination of the skin.”

Sunscreen also helps prevent wrinkles and aging of the skin, as was just proven for the first time. This study followed 903 Australians for almost five years, and those who used daily broad spectrum SPF-15 had no detectable increase in skin aging.

But what exactly defines a good sunscreen? Right now your local market probably has an entire wall selling dozens of brands in bright plastic, offering a range of SPF and customized for babies, women’s faces, men… on and on, a confusing mess for us consumers. We can cut through a bit of this with the basics:

Buy a broad-spectrum: just because it says SPF-50 or even 70 doesn’t mean it’s wonderful, as the SPF rating system only measures sunburns from UV-B sunlight and not UV-A sunlight. UV-A rays don’t cause your classic lobster-red burn but it is much more sinister, penetrating deeper into your skin layers and causing more subtle and permanent precancerous DNA damage. This is why it’s crucial to buy sunscreen that follows the US FDA’s new rules and literally says “broad spectrum” on the label. This means it contains ingredients covering both UV-A and UV-B

Get SPF 30, and don’t waste your money with SPF-50 and higher: SPF-15 is a good start since it blocks 93% of UVB, but I agree with the American Academy of Dermatology to use SPF-30 as a standard. SPF-50 and above may seem impressive but clinically offer miniscule extra protection over SPF-30. SPF-30 already blocks 97% of UVB and SPF-50 only one percent more, at 98%. In fact, it’s so misleading for consumers that the EU has banned any labels over SPF-50, and the US FDA is also finalizing this long overdue limitation.

Use more than you think is enough: Research has shown a large percentage of us don’t use enough each time we apply it, and thus aren’t getting the proper protection. A typical adult should be using 1 ounce (30 ml) each time for head to toe protection.

Don’t stay out longer: Many doctors are concerned that people, especially children, stay out in the sun longer after applying sunscreen and actually increase their risks for melanomas, forgetting to reapply as directed or not using enough in the first place.

Use it all year: this may surprise many, but the AAD also recommends this. Ultraviolet rays are much weaker during other times of year but can still add up to skin damage. You should at least consider always using a daily facial moisturizer which also has at least SPF-15 and apply on your face, ears and neck. I’ve used daily facial aftershave with SPF-20 since my college days, in winter or in summer.

Sunscreens also have many approved chemicals to choose from, which further confuses your consumer choices. Some groups, especially the Environmental Working Group, claim that two common ingredients in sunscreens, oxybenzone and retinyl palmitate (from vitamin A) are harmful to health and thus should not be included in sunscreens. For example, on their web page describing oxybenzone’s dangers, they state toxic issues with “hormone disruption; reproductive effects and altered organ weights in chronic feeding studies; high rates of photo-allergy; limited evidence of altered birth weights and increased odds of endometriosis in women.” However, not one governmental FDA bans these substances, and no major medical organization agrees with their warnings. The majority of research the EWG cites are done on animals or in test tubes and not on humans, and no major research with humans has shown serious dangers. Both of these chemicals have been, and continue to be, approved as safe by the US, the EU and Canada even after more than 20 years of usage. The American Academy of Pediatrics’ position statement on sunscreens has no specific warning against these or any other FDA approved chemicals for sunscreens. The American College of Dermatology published an updated statement last summer restating their support of these two ingredients.

Fortunately, even if you still remain concerned about these ingredients, there are hundreds of sunscreens available which don’t have either of these and can offer excellent broad spectrum coverage for both you and your children. Oxybenzone isn’t even as effective as other chemicals such as avobenzone, so you could search for that instead. And you don’t need retinyl palmitate because it doesn’t even block sunlight and is only added to allegedly help with photo-aging. The American Academy of Pediatrics specifically recommends products with with zinc oxide or titanium dioxide, as they are physical barriers and don’t get absorbed. If you want more consumer guidance, you can read the independent test results from Consumer Reports or also the sunscreen ingredients guide from Consumer Search, which also reviews natural sunscreens.