There are many uses for ultraviolet light in our daily lives. Some samples are listed below, based on each of the three most used wavelengths. It is important to note that higher energy ultraviolet light, such as midrange and shortwave, can be harmful if misused, and care must be taken when using those wavelengths for any application.
Longwave Ultraviolet Light (UVA)
Gemstone and Mineral Identification – Some mineral and gemstone specimens can fluoresce under UVA light. In some cases, an identification can be made based on the fluorescent response.
Currency, IDs and Documents – Security threads are embedded in United States currency, as well as other countries, and are easily detected with UVA light. Identification documents such as drivers licenses and passports may also include an ultraviolet watermark or sensitive ink that can easily be detected with UVA light. Visa stamps and stickers on passports may also use ultraviolet watermarks or inks, and can easily be detected with UVA light. Certain credit cards also contain fluorescent markings.
Crime Scene Inspection – Bodily fluids such as blood, urine, semen and saliva are fluorescent under UVA light. Even small quantities can be detected at crime scenes, and are used as forensic evidence. In some cases, illegal dumping can be traced using UVA light. UVA light can also be used in arson investigations, as accelerants such as gasoline, grease and paints can fluoresce.
Artwork Inspection and Authentication – UVA light can detect changes on the surface of artwork, as the specific fluorescent response may change depending on composition and age. UVA light can also detect over-painting, retouching and staining. Repairs to antiques can also be detected using UVA light.
Admission and/or Crowd Control – Quick drying fluorescent inks can be used for paying patrons as proof for re-admission or for alcoholic beverage control. UVA light is used most in this application.
Biological Applications – UVA light can be used for scorpion detection, as scorpions are brightly fluorescent. UVA light is also used to detect the presence of rodents, either from the fluorescent urine or fluorescent hair. Rodent urine fluoresces a blue-white color if fresh, or a yellow-white color if old. Rodent hair fluoresces blue-white, and can easily be detected. Many biological substances, such as proteins, fungi and molds fluoresce under UVA light. Recently, UVA light has been used in the fight against White Nose Syndrome, a disease which effects hibernating bats.
Ultraviolet Curing – Certain types of inks, coatings and adhesives are formulated so that these products dry, harden or cure when exposed to ultraviolet light. UVA light is used most in this application.
Sanitary Inspection – Many hospitality industries, such as the hotel industry, use UVA light to inspect for unsanitary bedding. This is done to either determine life cycle for mattress restoration or as a general performance test of the cleaning staff.
Dyes and Tracers – Many dyes and tracer compounds can be detected using UVA light. Industries such as the automotive industry use these dyes and tracers in order to detect leaks in various automobile systems.
Midrange Ultraviolet Light (UVB)
Gemstone and Mineral Identification – Some mineral and gemstone specimens can fluoresce under UVB light. In some cases, an identification can be made based on the fluorescent response.
Medical Usage – UVB light is used in the treatment of various skin conditions such as psoriasis. UVB light is also used in the tanning bed industry.
Shortwave Ultraviolet Light (UVC)
Gemstone and Mineral Identification – Some mineral and gemstone specimens can fluoresce under UVC light. In some cases, an identification can be made based on the fluorescent response. UVC light causes more minerals to fluoresce than any other wavelength of ultraviolet light.
Sterilization – UVC light is sometimes referred to as germicidal light. UVC light is high energy ultraviolet light that can kill microorganisms, and even alter DNA. This ability makes UVC light useful in sterilization at the workplace, such as workspaces and tools in biology laboratories or medical facilities. UVC can also be used in the home for the sterilization of keyboards, telephones, toothbrushes and other common items around the home. UVC is also used in the exterminator business as an aid in the elimination of bed bugs etc.