What are Sunscreens and what is their importance

Sunscreen is a lotion, spray, gel or other topical product that absorbs or reflects some of the sun's ultraviolet (UV) radiation and thus helps protect against sunburn. Depending on the mode of action, sunscreens can be classified into physical sunscreens (i.e., those that reflect the sunlight) or chemical sunscreens (i.e., those that absorb the UV light) Sunscreen use can help prevent melanoma and squamous cell carcinoma.

The most common sunscreens on the market contain chemical filters. These products typically include a combination of two to six of these active ingredients: oxybenzone, avobenzone, octisalate, octocrylene, homosalate and octinoxate. Mineral sunscreens use zinc oxide and/or titanium dioxide.

The SPF rating is a measure of the fraction of sunburn-producing UV rays that reach the skin. For example, "SPF 15" means that 1/15th of the burning radiation will reach the skin, assuming sunscreen is applied evenly at a thick dosage of 2 milligrams per square centimeter (mg/cm2). A user can determine the effectiveness of a sunscreen "by multiplying the SPF factor by the length of time it takes for him or her to suffer a burn without sunscreen."
Using sunscreen, seeking shade and wearing protective clothing are all important behaviors to reduce risk of skin cancer. Scientific evidence supports the benefits of using sunscreen to minimize short-term and long-term damage to the skin from the sun’s rays. But, using sunscreen decreases skin’s production of vitamin D. In that case there is a need of taking vitamin D supplements and a healthy diet to compensate the inadequacy and avoid further ailments due to lack of Vitamin D.