Tanning booth

# Overview
A tanning booth is a device that emits ultraviolet radiation, usually for the purpose of a cosmetic tan.  They are very similar to a tanning bed, but the design is such that it is intended to be used while standing up, rather than lying down.  Many persons prefer using a tanning booth rather than a tanning bed (or sunbed) for several reasons, but the main reason given is sanitation. This is because the user is always standing up in a booth, so there is little contact with the actual unit, unlike a traditional tanning bed.  While there are many stories of people catching diseases from tanning beds due to prior users (herpes, etc.) this is more myth than fact. Tanning beds are usually cleaned using an FDA approved disinfectant which is very inexpensive, and the UV itself controls bacterial growth, and is a very effective sterilizing agent.  Assuming the operator follows simple cleaning instructions, the risk is very minimal for either type of system.
Tanning booths generally use 160 watt VHO (Very High Output) or VHO-R (Very High Output with Reflector) lamps, but some less expensive systems use standard 100 watt HO (High Output) or RUVA (Reflector UVA) lamps.  Many people confuse "VHO-R" and "VHR ", with the latter being a trademark of Cosmedico lamps for their versions of the VHO-R lamps.  The average tanning booth has from 32 to 56 lamps and uses a 10 to 15 minute tanning session time.

# Comparing to tanning beds
Tanning booths are similar but distinct from tanning beds in that they are vertical rather than horizontal, but there are generally other difference as well.  Most tanning booths use the higher watt VHO and VHO-R lamp, which consume 160 watts, while most tanning beds use 100W HO lamps, although there are many exceptions.  Tanning booths are often said to give the user a better tan because it is easier to move while tanning, and most have handles above the head, which makes tanning under the arms and on the sides easier.  Most booths do not have a reflector system behind the lamps because they use the VHO-R lamps, which have a more effective reflector built inside the lamp itself.  This forces all the light to be focused out the front of the lamp, reducing lost UV from phase cancellation.  This is where two opposing waves (in this case, UV) that are out of phase with each other partially cancelling each other out, resulting in a loss of net UV that reaches the user.
Another difference that is not as obvious is that there are no pressure points when tanning inside a booth.  A person using a tanning bed is supported by the acrylic, and in these areas the blood flow is reduced.  Melanin production is somewhat reduced in these areas leading to a tan that is not completely even.  For most individuals, this isn't very obvious but certain individuals will experience circular areas with slight but noticeably less tan in those pressure areas.  Most (but not all) tanning booths do not have acrylics and instead use a wire mesh to protect the user from the lamps.  Although this results in a somewhat higher UV transmission, it does not offer the same protection that a solid acrylic sheet offers.
It is very common for tanning booths to have shorter exposure times than tanning beds.  This is partially due to the more common use of the 160 watt lamps, which produce more UVA and UVB than a 100w lamp.  Another factor is the choice of most manufacturers to use a higher UVB style lamp.  Because the FDA regulates exposure time using a method that biases against UVB (for all tanning units), this reduces the average exposure time from the tradition 15 to 20 minutes found on most tanning beds, to 10 to 15 minutes, with some booths even lower.  Tanning booths are subject to the same regulations as tanning beds, including posting the suggested time exposure in a conspicuous place on the tanning unit, and in the original owners manual.

# Common use
Tanning booths are not as common as tanning beds because they generally cost significantly more and because they are not as comfortable, as you tan standing up.  This limits the adoption of tanning booths over tanning bed particularly in the residential market, where comfort and price are primary considerations for purchasing.  There are no published statistics on the number of booths sold versus tanning beds, as all US tanning bed manufacturers are privately held companies and these numbers are considered proprietary.  Anecdotal evidence would indicate that less than 10% of the tanning units in professional tanning salons are booths.
One reason professional salons may choose a booth over a bed is the amount of space required, as a booth requires significantly less square footage than a bed.  Also, many booths have the option of a dressing room attached to the unit, which means the salon owner doesn't have to build a special room to house the unit, reducing their initial cost to install.  This often offsets the higher cost of the unit.

# Potential risks
As with any device that emits ultraviolet, there are risks, especially with overexposure.  Tanning booths are not safer than tanning beds, as the basic mechanics are the same.  See sun tanning for a more complete list of the potential hazards associated with tanning indoors or out.