Two types of sunblock exist. Both physical and chemical sunblocks are available. Zinc oxide and titanium dioxide are the physical type, meaning the sunblock is not absorbed by the skin's surface, according to "The New York Times." When applied to the skin, these ingredients reflect light, much like a mirror. Understanding which ingredient is right for you can help to protect you against the sun's harmful effects.
Derivation
True to its name, titanium dioxide is produced from titanium. In its natural state, titanium is chalky, white and highly reflective, according to "The New York Times." Zinc oxide is derived from the mineral zinc to create a material that is effective at blocking the sun's rays. When applied to the skin, zinc oxide can have a white appearance and also feel slightly heavy on the skin, according to Paula Begoun, an author and speaker known as "The Cosmetics Cop" for her work in evaluating the safety and efficacy of cosmetics.
Size in Sunscreens
两个二氧化钛和氧化锌，从白垩，反光材料而得。虽然这是反射太阳的光线是有益的，这些材料的应用可以在皮肤上没有吸引力，因为它导致了白色，垩白的外观，根据环境工作组。出于这个原因，防晒霜制造企业合作，以规模降化学防晒剂的颗粒。二氧化钛按比例缩小到纳米10和100之间（nm）时，所使用的测量非常小的颗粒的测量的单元，而氧化锌被按比例缩小到30〜200纳米。这使得在皮肤上的每个特定少去明显，但如果没有如此之小，它穿透皮肤。
Skin Irritation
Titanium dioxide is noncomedogenic, meaning it does not contain oil that can clog the skin's pores, according to "The New York Times." In addition to its sun-fighting properties, zinc oxide is known for its noncomedogenic and antimicrobial properties. This can help to enhance wound healing. However, the heavy or thick nature of the products can sometimes contribute to clogged pores, although this likelihood is smaller than other sunscreen products, such as avobenzone and oxybenzone, according to Begoun.
Effectiveness
In terms of effectiveness, zinc oxide has a slight edge over titanium dioxide, according to SmartSkinCare. Titanium dioxide is effective at blocking ultraviolet-B and short-wave ultraviolet-A rays, but it is less effective than zinc dioxide at blocking long ultraviolet-A rays. Zinc oxide's ability to block different types of rays makes it one of the most effective sun protection products on the market at fighting the sun's rays. However, zinc oxide often is combined with additional ultraviolet-B blockers to provide the most complete broad-spectrum sunscreen.
Considerations
When trying to find the right sunscreen ingredient for you, Begoun recommends experimenting with each ingredient to ensure it will not cause skin irritation. If your sunscreen is combined with a foundation or other makeup, be sure to apply a sufficient layer to offer sun protection. Because zinc oxide offers slightly better coverage across the sun's ultraviolet spectrum, you may wish to begin with this ingredient, then switch to titanium dioxide if you find you cannot wear zinc dioxide.