A tanning bed or sunbed is a device emitting ultraviolet radiation (typically 95% UVA and 5% UVB, +/-3%) used to produce a cosmetic tan. Regular tanning beds use several fluorescent lamps that have phosphor blends designed to emit UV in a spectrum that is somewhat similar to the sun. Smaller home tanning beds usually have 12 to 28 100 watt lamps while systems found in salons can run from 24 to 60 lamps each consuming 100 to 200 watts.
There are also "high pressure" tanning beds that generate primarily UVA with some UVB by using highly specialized quartz lamps, reflector systems and filters. These are less common and much more expensive, thus less commonly used. A tanning booth is quite similar to a tanning bed, but the individual stands while tanning and the typical power output of booths is higher.
Because of several alleged adverse effects on human health, the World Health Organization does not recommend the use of UV tanning devices for cosmetic reasons For example, using a sunbed without goggles may lead to a condition known as arc eye.
Europeans may enjoy tanning seasonally, but less so than Americans. This is due to many areas in Europe having significantly fewer days of sunshine than the U.S., so Europeans are more likely to use a tanning bed all year long, for both the cosmetic and mood altering benefits. European tanning beds generally use a different type of lamp as well, with UVB ratings in the 1% to 3% range (using US measuring methods) whereas most tanning beds sold in the US use 4.2% to 6.5% UVB ratings, and aftermarket lamps with up to 8.5% or higher being popular. Of course, these lamps have less UVA and will produce a sunburn quicker, but many Americans seem to like them because a short session produces a "reddening", or instant gratification. These lamps actually produce a slower deep tan (but a faster base tan) that fades faster, but are simply marketed as "hotter", although technically they have about the same amount of UV but with different ratios of UVA and UVB.
While the primary reason for both Americans and Europeans to use a tanning bed is cosmetic, there are many other reasons why they are used. It is common for people to tan simply because it makes them feel good. Also, most tanning beds generate a large amount of heat, including infrared, which has deep penetrating action that can relieve minor muscle aches.
The tan produced by a tanning bed is not as deep as a tan produced in the sun. This is because tanning beds have higher overall levels of UV than the sun on a typical day, so the exposure times are shorter than the average session spent in the sun to achieve the same amount of tan. This can cause someone with a dark indoor tan to go outside and get a bad sunburn quickly because the deeper levels of their skin have not been exposed previously, and have no natural protection above what white skin would have. It is strongly recommended that a person does NOT tan indoor and outdoors on the same day, due to the likely chance that they will get overexposed. Because overexposure actually destroys melanin, getting a sunburn will result in LESS tanning. The popular wisdom that you "need to burn to tan" or that a sunburn will turn into a tan is simply wrong, and greatly increases your chances for skin cancer later in life.
The ballasts regulate the power that is sent to the lamps, so that if you install a 160W lamp in a tanning bed that has 100W ballasts, only 100W will be delivered to the lamp. The lamp will still ignite and offers no benefits over a 100W lamp, and may actually create less UV since it is designed for higher current. It will not damage the system, although installing 160W lamps with a 100W ballast will result in very short lamp life, as the 160W lamp cathode/anode sets are typically designed to run at much higher temperature. The lamp starter part of the bed (small tan cylinder) is used only on beds with choke ballasts and is a simple plasma starting switch. It has no bearing on how powerful the bed is. Either it works (the lamp lights) or doesn't. They are installed one per lamp on beds that use them, and are generally replaced every couple of years in salons or every 6 to 10 years for infrequently used systems.
Like all fluorescent lamps (and other plasma devices such as neon lamps), low pressure tanning lamps work when the ballast directs enough energy to the lamp that a plasma is generated inside the lamp. The lamps are coated on the inside with special phosphors and contain a small amount of mercury (20mg typical). Unlike high pressure lamps, the glass that is used in low pressure lamps automatically filters out all UVC. Once the plasma is fully flowing (less than one second), the plasma literally strips away the outer electrons from the mercury, sending them into the phosphor, which produces photons in the proper spectrum for tanning. The electrons, now in a lower energy state, will jump back into place onto the first mercury atom they find with an electron missing.
The surfaces on which the tanner lies and shield the user by physical separation from the lamps on the bench and canopy are typically referred to as the "acrylics". Acrylics are manufactured from a base material of Polymethyl Methacrylate (PMMA), type UVT (UV-transmitting), which has been formulated to have a spectral transmittance in the wavelength region 290-400 nm. This should not be confused with a standard acrylic, or "plexiglass", which would not transmit within this spectral range effectively inhibiting the tanning properties of the unit.
Base resins are typically cell-cast or extruded into sheet and then thermoformed to manufacture the acrylics. On occasion, depending on the complexity of the part, the resin will be injection molded. It is due to the expense of the specially formulated resin, handling considerations and manufacturing processes which drive the cost of acrylic parts, which can be high when compared to standard grade acrylic which can be purchased at your local home improvement store.
These acrylic materials should never be cleaned with any agent containing alcohol (i.e. glass cleaner), as this will adversely affect the material surface causing a phenomenon known a "crazing". This will present itself as small fissures resembling spiderwebs forming where stresses are most concentrated on the part and in the region which was subjected to the chemical attack.
These shields break down over time as they are exposed to UV and oxygen and must be reconditioned every few years. Failure to do so will reduce the transparency of the acrylic to UV rays, although to the eye it will still appear perfectly clear. The reconditioning is most commonly done with a compound called Novus #2, which is a slightly gritty cleaning compound that removes a microlayer of the acrylic, restoring to near new condition and is used in many other industries. This being said, a better practice is to replace the acrylic as the oxidation described above affects the physical properties of the material rendering it less impact resistant.
Most mainstream tanning beds built today use similar electronics, with the primary differences being in the design and quality of the frame and shell of the bed, as well as the number and type of lamps used. The newer electronics are very promising because of their lower power usage, cooler running temperature, and more environmentally friendly components.
In the United States, the maximum exposure time in most tanning beds is 20 minutes but varies from bed to bed. This is calculated by the manufacturer according to the amount of time needed to produce 4 MEDs (minimal erythemal doses). This is essentially 4 times the amount of UV that is required to produce a reddening on unexposed skin. A person would start with a much shorter session time and work their way to the maximum exposure time in about 4 weeks. Every tanning bed is required to have a "Recommended Exposure Schedule" on both the front of the tanning bed and in the owners manual. It must also list the original lamp that was certified for that particular tanning bed, and salon owners must replace the lamps with either the exact same lamp, or a lamp that is certified by the lamp manufacturer to be legally equivalent. Lamp replacement and salon compliance is regulated by the individual state in the USA, whereas the manufacturing and sale of new equipment is regulated by the federal government.
Since many factors can change the performance of any given individual lamp, the FDA requires that every tanning bed model is certified separately, and lamps themselves do not have MED ratings. Lamps do have typical TE (or Time Exposure) ratings, but these are not used for certifying beds. Session times on beds can range from 5 minutes to 45 minutes, depending on many factors.
Exposure to ultraviolet radiation induces two of the most common DNA mutations known in cellular biology. Those include cyclobutane–pyrimidine dimers (CPDs) and 6–4 photo products (6–4PPs) and their Dewar valence isomers.. Cells have developed a number of repair mechanisms to counteract the DNA damage caused by ultraviolet radiation and other toxins. In human cells, a repair process is initiated after DNA damage is detected in which the damaged DNA is removed before it is replicated. As humans age, their cellular repair mechanisms make more errors because they have accumulated years of oxidative stress from daily life.. Over time, it is more difficult for the cell to find and destroy aberrant DNA. The replication of damaged DNA leads to cancer, and exposure to UV radiation sets a process in motion that can take decades to ultimately cause skin cancer. Similarly, most people who smoke cigarettes do not get lung cancer until decades of use have passed. Most critically, if a mutation occurs within a gene that regulates cell division, the cell becomes prone to malignancy. For example, squamous cell carcinoma (a type of skin cancer) is caused by a UVB induced mutation in the p53 gene.
Exposure to UV radiation has a detrimental effect on the immune system. Exposure causes changes in antigen presentation by Langerhans cells and macrophages. Also, the activities of natural killer cells and T cells is reduced. Last, cytokine regulation is disrupted by UV exposure. Ultraviolet radiation exposure may facilitate the growth of skin neoplasms and the spreading of skin-associated infections due to stimulation of suppressor T cells.
While the dangers of UVB are widely recognized, the dangers of UVA are less understood. UVA is less likely to burn the skin, and it has been called the "bronzing light." However, it is clearly associated with inducing aging changes in the skin and in promoting the development of skin cancer. This is because UVA penetrates the skin more deeply than UVB, and therefore causes damage on a deeper level. Most aging of skin is due to UVA rays destroying collagen and connective tissue beneath the superficial layer of the skin. UVB rays do not reach as far below the skin. Excessive exposure to UVA radiation has its risks, which could may cause premature aging, including wrinkles, sunspots, and loss of skin elasticity.
One study conducted amongst a college student population found that awareness of the risks of tanning beds did not deter the students from using them.
Although rare, it is possible for tanning beds to be a vector for infections of pubic lice, also known as crabs. If the surface of the bed is not properly cleaned or if towels provided by the salon are not washed in hot water, crab lice can survive for several days on these surfaces. Crab lice are difficult to see on the acrylic of a dimly lit tanning bed, and they are not killed by anti-bacterial or anti-viral cleaning agents used in salons. They can only be killed by physical removal or by the use of insecticides such as pyrethrin.
While there appears to be a link between indoor tanning beds and cancer, the connection is not possible to indisputably prove because people who tan indoors also tan outdoors. Furthermore, cancer shows up decades after exposure. Lastly, there is a genetic component to skin cancer. None of this changes the fact that there are risks (and benefits, such as vitamin D production) associated with exposure to ultraviolet.
Tanning makes most people feel good. To understand how this happens, researchers set out to determine if endorphin levels were increased after tanning. They concluded that there were no significant differences in the mean plasma levels of β-endorphin between people who were exposed to tanning beds and those who were not. The positive psychological benefits of tanning may be due to factors other than endorphins.
It is believed that indoor tanning beds are useful for the treatment of SAD (Seasonal Affective Disorder), though this is disputed at present. It is plausible that the benefit that many SAD patients experience are more due to tanning causing them to feel good in general, rather than treating the SAD itself.
While a tan that is developed in a tanning bed does offer some protection from overexposure to the natural sun, it is more cosmetic than a natural tan. A tan provides a natural SPF of between 2 and 4. Depending on the intensity of the sun outside, it may be advisable to use additional lotion with SPF even if a base tan is present.
A more controversial benefit of tanning indoors rather than tanning outside is the amount of control the tanner has. If a person decides to get a suntan and wants to minimize the risk of getting a sunburn, a tanning bed offers an environment that delivers the same amount of UV in a given period of time, day after day. In contrast, the amount of UV that reaches the ground can vary from minute to minute and the longer tanning times results in deeper exposure. This doesn't make the tan in a tanning bed safer per se, but it can reduce the chance of a sunburn as it allows total control over the amount of exposure a person receives.
Tanning beds also offer time savings when compared to tanning outdoors. Most tanning beds offer a maximum session time of 20 minutes and a person can maintain a tan with 1 to 2 sessions per week. For individuals living in urban areas, or who work extended hours, a tanning bed may be the only opportunity for tanning or UV exposure of any kind.
Initially, tanning beds were virtually unregulated in the US, but in 1988 (and later updated in 1999) the primary source of regulation at the federal level was 21 CFR 1040.20 This law was designed primarily to ensure that all tanning beds sold or used in salons adhered to a general set of safety rules, with the primary focus on tanning bed and lamp manufacturers in regards to maximum exposure times and product equivalence. It is left up to each individual state to determine the regulations for salons themselves, and as such, many states are still not regulated beyond these basic federal rules.
Several companies continue to license the Wolff name and use their lamps because of the name recognition, although this has steadily diminished over the years as other lamp builders have created lamps that are arguably as good as or better. Licensing is not required to use Wolff lamps, but it is required to call a tanning bed a "Wolff System" and use the Wolff System logo, a yellow circle with horizonal bars and the name "Wolff Systems" in black. Tanning beds that use Wolff products but do not pay royalties can use only the term "Powered by Wolff," which is unique in the industry.
Most modern tanning beds have not changed much from the original systems. The lamp technology and electronics have evolved over the years, but the basic "low pressure" tanning bed has not evolved. The original electronics used in the first tanning beds, both "European choke" and magnetic, are still in use today although there are now many other choices including electronic and high frequency. The lamps are still fluorescent type, using special phosphors that create a spectrum in the UVA and UVB range although there has been a great deal of advancement over the years to make the light spectrum they emit more "sun-like".
The first original tanning lamps were discovered by accident in 1903 by a German company called Heraeus who were developing lighting systems for the home and for industrial usage. These lamps were of the high-pressure metal halide variety. They discovered that the light that was developed for visible light purposes also emitted ultra-violet light. In the 1920s and 1930's they (Heraeus) first started to market and sell single lamp, self standing tanning/wellness devices. The first high-pressure tanning beds incorporating more than a single high-pressure lamp were manufactured in the mid to late seventies by companies such as Ultrabronz and JK Ergoline and in the 1980s the first high-pressure units were exported to the United States.
These units require special filter glass to remove the UVC and the majority of the UVB that is emitted and are difficult to manufacture because the alignment of the lamps is more critical than in traditional low-pressure tanning beds. They are generally large units, with a padded area to lie on or an acrylic and 6 to 36 lamps in a canopy or canopy and bench configuration, the tanning effect is much deeper and requires only a maintenance exposure of about 2-3 times per month compared to every 48 hours for regular tanning beds. They are much more expensive to operate, thus more expensive for the user. Retail prices in the $20,000 to $35,000 range are common with individual sessions costing $20 to $45, depending on the market.
Another trend is spray on tanning (a form of sunless tanning), using either special booths or a hand held setup similar to an airbrush. Many people who try spray on tanning often still go to the tanning salon, and use the spray on as a way to jump start the appearance of a tan, while others use it as a way to look tan while avoiding UV exposure of any kind. This is also demonstrated by the large number of indoor tanning lotions that have "bronzers" included, which is similar to the chemicals used for spray on tans, DHA.