When you’re headed to the beach, do you reach for your “sunblock” or “sunscreen“?
You may have heard these words used interchangeably to refer to various types of liquid or spray UV protection. But sunblock and sunscreen are actually two separate products with differing ingredients, consistencies, and methods of protecting you from the sun.
Sunscreens, also known as chemical blockers, absorb the sun’s ultraviolet rays and convert them into non-damaging red light, or heat. They come in both sprays and lotions and must be massaged into the skin at least 20 minutes before sun exposure. Since sunscreens are absorbed by the skin, they don’t leave a white cast.
Sunblock, sometimes called physical blockers or mineral sunscreen, reflect ultraviolet rays back into the environment. They are slathered onto the skin right before sun exposure and act as a physical barrier between you and the sun. Sunblock ingredients include either zinc oxide or titanium dioxide, which is what gives sunblock its signature white cast.
Both sunscreen and sunblock offer powerful protection from ultraviolet light, and neither is better or worse than the other. It’s all up to personal preference. People with sensitive skin may prefer sunblock to sunscreen since one of the sunscreen’s ingredients, oxybenzone, can cause allergic reactions. Sunblock is also less likely to clog pores or cause breakouts, making them a good choice for acne-prone individuals. Sunscreen, on the other hand, has much easier application and better water-resistant formulas, so they may be a better option for outdoor activities and swimming.
When choosing what type of UV protection to buy at the store, you’ll find the products labeled with phrases such as “broad spectrum” and “SPF.” But what do these actually mean? Broad spectrum sunscreens and sunblock offer protection from the “spectrum” of ultraviolet light, both ultraviolet A (UVA) and ultraviolet B (UVB). UVA rays can cause skin aging, including premature age spots, wrinkles, and saggy skin, while UVB rays are what causes sunburn. Together, both rays cause skin cancer. SPF stands for Sun Protection Factor and refers to how well the product protects you from sunburn. SPF 15 filters out 93% of the sun’s UVB rays, while SPF 30 filters out 97%. The American Academy of Dermatology Association recommends broad spectrum sunscreen or sunblock with SPF 30 or higher for the best protection when out in the sun. It’s important to note that no sunscreen offers 100% protection from UV, so you should stick to the shade when possible and wear sun-protective clothing, which can include long-sleeved shirts, lightweight sun hoodies, and wide-brim hats.
Whether you use sunscreen or sunblock, you’ll need to reapply your UV protection to ensure your skin stays protected. Over time, the sun’s ultraviolet rays can break down the sunscreen’s ingredients, or your sunblock can be washed away by ocean waves or sweat. If you’re not sweating or swimming, a good rule of thumb is to reapply sunscreen every two hours. But, if your skin begins to feel or look dry, redden, or you start to feel a prickly or burning sensation, these are signs that your UV protection has worn off and needs to be reapplied. Otherwise, UV protection should be reapplied after sweating, toweling off, or getting out of the water. If you’re swimming in the sun for long stretches of time, sunscreens and sunblock labeled “water resistant” will last longer than regular UV protection. However, these should still be reapplied every 40 to 80 minutes.
UV protection is vital in protecting yourself from skin cancer, the most common type of cancer in the United States. Be proactive in your health by applying sunscreen or sunblock whenever you head outside, whether that’s trips to the beach or just walking your dog.