If you have wondered, "How does suntan lotion work?", it is quite an interesting subject. Also sometimes internationally known as sunscreen and sunblock, suntan lotion can also be a spray or any type of topical product. The goals are to lower the risk of skin cancer as well as protecting the skin from ultraviolet (UV) radiation and reducing sunburn or other damage to the skin. Protection is against UVB ultraviolet radiation which causes sunburn and UVA ultraviolet radiation that causes long-term damage such as aging of the skin, wrinkles, and possibly skin cancer. Most suntan lotions work by either absorbing ultraviolet light or reflecting the light, and they may have both compounds or materials and are called "broad spectrum" sunscreens.
In the United States, however, the term "suntan lotion" refers to the opposite of "sunscreen" because it is used to maximize UV exposure and allow tanning instead of blocking it. It also moisturizes the skin and may or may not have SPF protection. Most people use SPF (Sun Protection Factor) 15, but SPF 25 or higher should be used on children or adults who tend to get eczema. Higher SPF can be applied with a stick applicator to exposed areas such as nose, ear lobes, shoulders, etc. Be aware that even the highest SPF cannot protect the skin against UVA and UVB rays, so you should stay in the shade between 11 am and 3 pm, which are the hottest times.
Since suntan lotion takes some time to work, apply half an hour before going into the sun. An adult should apply about two tablespoons (30 to 40 grams) and children need about twenty grams. Apply the lotion again within two hours. It is also advised to cover children with light clothing and not to expose babies under twelve months to the sun at all. If you want to go swimming, make sure your suntan lotion is waterproof or water-repellent.
Although suntan lotion may have a shelf life of two-and-a-half years, you really should replace it every year because it can be damaged by heat and bacteria. If it separates or doesn't smell right, it has been destroyed, and you should throw it away. Since it should be kept in a shady and cool place, it is suggested that you keep it in the refrigerator.