When it comes to sun care, knowing the difference between sunblock and sunscreen (i.e. physical or mineral filters versus chemical ones) isn’t just another to-may-to, to-mah-to situation. Recently it seems like there’s been an onslaught of not-so-great news regarding the sun and skin care—melanoma rates are at their highest points ever, a lot of SPFs aren’t living up to their claims, and vitamin A derivatives in sunscreen could actually be increasing your chances of developing a skin cancer.

Now that it’s high season for the sun and UV rays, it’s even more imperative than usual that you know what’s up when buying SPF. And one of the most important ways that you can keep yourself sunburn-free is by knowing how to pick out the right formula for you—because wearing it on the reg is the best protection factor of all.

Physical sun protectants, zinc oxide or titanium dioxide, are called sunblocks. They work by deflecting ultraviolet rays from penetrating the skin Carla Burns, research analyst at the Environmental Working Group (EWG) says. On the other hand chemical filters, such as avobenzone, oxybenzone, octinoxate, homosalate, octocrylene, etc., are actually sunscreens. That’s because they absorb the UV rays and turn that into heat through a chemical reaction in the skin.

According to Burns, the main (and potentially only) drawback of a mineral sunscreen is the chalky white film it tends to leave—a small price to pay for adequate sun protection. Since the main sun-protection agent is a mineral, the formulas do need to be shaken every time upon use to make sure you’re getting the right amount of the active ingredient.

While chemical sunscreens, on the other hand, go on more seamlessly (i.e. it isn’t painfully clear that you’re slathered head to toe in SPF 50), there is a price to pay for inconspicuousness. For starters, they’re not always great for the environment, which is why Hawaii is attempting to ban formulas with oxybenzone and octinoxate, which have the ability to damage the ocean, coral life, and the fish population.

Beyond being punishing to Mother Earth, those chemicals could also be disruptive to the human body, and especially fertility. She explains that the EWG has flagged oxybenzone, a widely used non-mineral active ingredient, as not only a skin sensitizer, but also a hormone disruptor.

Of course, the most important thing is that you wear the stuff, and if you’re stuck on where to start, try one of these dermatologist-approved products.

Although sunscreen can stain your clothing the FDA advises against taking sunscreen pills.