Swim shirts are relatively new to the consumer market, but are growing in popularity. They are generally more loose fitting and casually worn. Their primary purpose is to offer an alternative to sunscreen to protect the wearer's skin from the sun's UV radiation and possible skin cancer. Many swim shirts carry a UPF rating of 50+, which blocks out over 98% of the sun’s harmful rays. Many people find that sunscreen isn’t always enough because it is often not used properly and some have skin allergies or sensitivities to chemicals in sunscreens. Children's skin can be especially sensitive to the sun and sunscreens. Many children, and parents, find it is much easier to put on a swim shirt as it is loose and easily slipped on. it is comfortable and yet gives sun protection. Even though the name generally applies to water sports, people use swim shirts for an array of activities: swimming, boating, golfing, tennis, gardening, playing in the sprinklers, water parks, beach trips, pool play, rivers and lakes, water skiing, surfing, snow skiing, sledding, skimboarding, in mixed martial arts and Brazilian jiu-jitsu, and even as normal everyday clothing.