A tanning bed is a cosmetic device that emits ultraviolet radiation such as UVA and also UVB to generate artificial tanning. Historically, medical devices that emit UVA were developed and adopted for modern indoor tanning. Since UVA (Ultraviolet A of the sun) has less biological effects such as reddening of the skin than UVB (Shortwave Ultraviolet rays), these early tanning beds were considered to be safe. However, it was soon realized that continued use of these devices could also cause sunburns, wrinkles, skin cancer, and were not very effective at inducing tans, so they were eventually phased out. Today, devices that emit a combination of UVA and UVB are predominantly used.

One of the strongest criticisms to the use of indoor tanning beds occurred in December, 1994, when the American Medical Association (AMA) adopted a resolution calling for a ban on the sale and use of tanning equipment, except for medical purposes. However, this resolution was rejected by the United States Federal Trade Commission (FTC), an organization that regulates the sale and marketing of indoor tanning equipment.

It has now been established that modern tanning beds and sun lamps typically emit about 93% to 99% UVA radiation - three times the UVA radiation given off by the sun. Tanning occurs when the skin produces additional pigment (coloring) to protect itself against burn from these ultraviolet rays. Continued exposure to UV rays can result in a number of unwanted complications such as eye injury, premature skin aging, light-induced skin rashes, and chances of developing skin cancer. UVB can even cause actual skin burning.

There are three types of common skin cancers - basal cell carcinoma, squamous cell carcinoma, and melanoma and they are all linked to UV radiation. The first cause, according to medical research, is mutations caused the damage inflicted to DNA. Secondly, UV also activates oxygen molecules that damage DNA and other cellular structures; and lastly, localized immunosuppression, that blocks the body's natural ability to protect itself from cancer. The first two types - basal cell and squamous cell - are treatable if detected early but malignant melanoma is often fatal.

A study conducted in Sweden concluded that people who used tanning beds more than 10 times a year were seven times more likely to develop malignant melanoma than those who did not use tanning beds as often, establishing the fact that tanning beds are a major factor that contributes to the development of malignant melanoma.

Other studies have shown that over exposure to ultraviolet rays can also burn or damage the retina, and alter the structure of the lens forming a cataract, which if left untreated may result in complete blindness. Ultraviolet rays can also cause premature skin aging since a tan is damaged skin that is more likely to wrinkle and sag, and when in combination with certain cosmetics and medicines, may cause adverse skin reactions such as rashes and cold sores.

In spite of all the health risks associated with indoor tanning beds, it is estimated that 28 million Americans are tanning indoors annually at about 25,000 tanning salons around the country. The indoor tanning industry in the United States also continues to thrive, raking in as much as $2 billion a year.