Mineral sunscreens are preferred by some people because they provide broad-spectrum protection against both UVA and UVB rays without the use of chemicals. Mineral sunscreens work by using physical blockers like zinc oxide or titanium dioxide to reflect the sun's rays off the skin. This is in contrast to chemical sunscreens, which work by absorbing the sun's rays and converting them into heat. Some people prefer mineral sunscreens because they are less likely to cause skin irritation or allergic reactions than chemical sunscreens. Additionally, mineral sunscreens are considered to be more environmentally friendly because they are not known to have negative effects on aquatic life or coral reefs. However, mineral sunscreens can be more difficult to apply and may leave a white residue on the skin, which some people find unappealing.