Sun protective clothing
Encyclopedia
Sun protective clothing is clothing
Clothing
Clothing refers to any covering for the human body that is worn. The wearing of clothing is exclusively a human characteristic and is a feature of nearly all human societies...

 specifically designed for sun protection and is produced from a fabric
Textile
A textile or cloth is a flexible woven material consisting of a network of natural or artificial fibres often referred to as thread or yarn. Yarn is produced by spinning raw fibres of wool, flax, cotton, or other material to produce long strands...

 rated for its level of ultraviolet
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...

 (UV) protection. A novel weave structure and denier (related to thread count per inch) may produce sun protective properties. In addition, some textiles and fabrics employed in the use of sun protective clothing may be pre-treated with UV inhibiting ingredients during manufacture to enhance their UV blocking capacity.

Not only limited to UV-inhibiting textile use, sun protective clothing may also adhere to specific design parameters - including styling appropriate to full coverage of the skin most susceptible to UV damage. Long sleeves, full collars, and full-length trousers and skirts are common styles for clothing as a sun protective measure.

A number of fabrics and textiles in common use today need no further UV-blocking enhancement based on their inherent fiber
Fiber
Fiber is a class of materials that are continuous filaments or are in discrete elongated pieces, similar to lengths of thread.They are very important in the biology of both plants and animals, for holding tissues together....

 structure, density
Density
The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...

 of weave
Weave
Weave may refer to:*Hair weave*Mozilla Weave*Weaving...

, and dye
Dye
A dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and requires a mordant to improve the fastness of the dye on the fiber....

 components - especially darker colors and indigo
Indigo
Indigo is a color named after the purple dye derived from the plant Indigofera tinctoria and related species. The color is placed on the electromagnetic spectrum between about 420 and 450 nm in wavelength, placing it between blue and violet...

 dyes. Good examples of these fabrics contain full percentages and/or blends of heavy weight natural fibers like cotton, linen and hemp or light-weight synthetics such as polyester
Polyester
Polyester is a category of polymers which contain the ester functional group in their main chain. Although there are many polyesters, the term "polyester" as a specific material most commonly refers to polyethylene terephthalate...

, nylon
Nylon
Nylon is a generic designation for a family of synthetic polymers known generically as polyamides, first produced on February 28, 1935, by Wallace Carothers at DuPont's research facility at the DuPont Experimental Station...

, lycra and polypropylene
Polypropylene
Polypropylene , also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging, textiles , stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes...

. Natural
Nature
Nature, in the broadest sense, is equivalent to the natural world, physical world, or material world. "Nature" refers to the phenomena of the physical world, and also to life in general...

 or synthetic indigo dyed denim
Denim
Denim is a rugged cotton twill textile, in which the weft passes under two or more warp threads. This produces the familiar diagonal ribbing identifiable on the reverse of the fabric, which distinguishes denim from cotton duck. Denim has been in American usage since the late 18th century...

, twill
Twill
Twill is a type of textile weave with a pattern of diagonal parallel ribs . This is done by passing the weft thread over one or more warp threads and then under two or more warp threads and so on, with a "step" or offset between rows to create the characteristic diagonal pattern. Because of this...

 weaves and canvas
Canvas
Canvas is an extremely heavy-duty plain-woven fabric used for making sails, tents, marquees, backpacks, and other items for which sturdiness is required. It is also popularly used by artists as a painting surface, typically stretched across a wooden frame...

 are also good examples. However, a significant disadvantage is the heat retention caused by heavier weight and darker colored fabrics.

As sun protective clothing is usually meant to be worn during warm and humid temperatures, some UV-blocking textiles and clothing may be designed with ventilated weaves, moisture wicking and antibacterial properties to assist in cooling and breathability.

History

Although clothing has been used for protection against solar exposure for thousands of years, in modern times sun protective clothing was popularized (but not exclusively used) in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 as an option or adjunct to sunscreen lotions and sunblock creams. Sun protective clothing and UV protective fabrics in Australia now follow a lab-testing procedure regulated by a federal agency: ARPANSA. This standard was established in 1996 after work by Australian swimwear companies. The British standard was established in 1998. The NRPB (National Radiological Protection Board) forms the basis of the British Standards Institute standard. Using the Australian method as a model, the USA standard was formally established in 2001, and now employs a more stringent testing protocol: This method includes fabric longevity, abrasion/wear and washability. (To date, the focus for sun protection is swimwear, appropriate hat
Hat
A hat is a head covering. It can be worn for protection against the elements, for ceremonial or religious reasons, for safety, or as a fashion accessory. In the past, hats were an indicator of social status...

s, shade devices and sunglasses for children.) UPF testing is now very widely used on clothing used for outdoor activities.

The original UPF rating system was enhanced in the United States by the ASTM (American Standards and Testing Methods) Committee D13:65 at the behest of the U.S. Federal Trade Commission (FTC) to qualify and standardize the emerging sun protective clothing and textile industry. The FDAU.S. Food and Drug Administration (FDA) had reviewed clothing making sun protection claims (SPF, % UV blockage, or skin cancer prevention claims) in 1992. Only one brand of sun protective clothing, Solumbra, was reviewed and cleared under medical device regulations. The FDA initially regulated sun protective clothing as a medical device, but latter transfered oversight for general sun protective clothing to the FTC. The UPF rating system may eventually be adopted by interested apparel and domestic textile/fabric manufacturers in the industry at large as a "value added" program strategic to complement consumer safety and consumer awareness.

Fabric

Factors that affect the level of sun protection provided by a fabric, in approximate order of importance, include weave
Weave
Weave may refer to:*Hair weave*Mozilla Weave*Weaving...

, color
Color
Color or colour is the visual perceptual property corresponding in humans to the categories called red, green, blue and others. Color derives from the spectrum of light interacting in the eye with the spectral sensitivities of the light receptors...

, weight
Weight
In science and engineering, the weight of an object is the force on the object due to gravity. Its magnitude , often denoted by an italic letter W, is the product of the mass m of the object and the magnitude of the local gravitational acceleration g; thus:...

, stretch
Stretching
Stretching is a form of physical exercise in which a specific skeletal muscle is deliberately elongated, often by abduction from the torso, in order to improve the muscle's felt elasticity and reaffirm comfortable muscle tone. The result is a feeling of increased muscle control, flexibility and...

, and wetness. In addition, UV absorbers may be added at various points in the manufacturing process to enhance UV protection levels. The more open/less dense the fabric, the worse the protection(weave weight stretch).The darker the color, the more dye, the better the protection. Getting a fabric wet reduces the protection as much as half except for silk and viscose which can get more protective when wet. Polyester contains an ester(benzene) ring that absorbs UV light.

There is some indication that washing fabrics in detergents containing fabric brighteners, which absorb UV radiation, might increase their protective capability. Studies at the University of Alberta
University of Alberta
The University of Alberta is a public research university located in Edmonton, Alberta, Canada. Founded in 1908 by Alexander Cameron Rutherford, the first premier of Alberta and Henry Marshall Tory, its first president, it is widely recognized as one of the best universities in Canada...

 also suggest that darker colored fabrics can offer more protection than lighter colored fabrics.

Provide better protection: *Specially manufactured fabrics * black or dark blue denim jeans *wool garments *Satin finished silk of any weight *polyacrylonitrile *100%polyester *Shiny polyester blends *tightly woven fabrics *unbleached cotton(most cotton sold is bleached)

Provide low protection: *polyester crepe *bleached cotton *viscose *knits *undyed/white jeans *worn/old fabric

UPF rating

A relatively new rating designation for sun protective textiles and clothing is UPF (Ultraviolet Protection Factor). Unlike SPF (Sun Protection Factor) that traditionally uses human sunburn testing in a laboratory environment, UPF measures both UVA and UVB radiation transmittance using a laboratory instrument (spectroradiometer) and an artificial light source and translates these results using a mathematical expression based upon the sunburn action spectrum (erythema action spectrum) integrated over the UV spectrum.

Developed in 1998 by Committee RA106, the testing standard for sun protective fabrics in the United States is the American Association of Textile Chemists and Colorists (AATCC) Test Method 183. This method is based on the original guidelines established in Australia in 1994. Below is the Australian/New Zealand Standard for Sun Protective Clothing and Swimwear, which is now considered the industry standard in rating such sun protective clothing:

UPF Ratings and Protection Categories
UPF Rating Protection Category % UV radiation Blocked
UPF 15 - 24 Good 93.3 - 95.9
UPF 25 - 39 Very Good 96.0 - 97.4
UPF 40 - 49 Excellent 97.5 or more
UPF50+ Considered the Ultimate in UV Sun Protection

Summary UPF Testing Protocol

AATCC 183 method defines the UPF rating for a fabric/textile as the ratio of UV measured without the protection of the fabric (compared to) with protection of the fabric. For example, a fabric rated UPF 30 means that if 30 units of UV fall on the fabric only 1 unit will pass through. A UPF 30 fabric that blocks or absorbs 29 out of 30 units of UV is therefore blocking 96.7% UV. UPF tests are normally conducted in a laboratory with a spectrophotometer or a spectroradiometer
Spectroradiometer
Spectroradiometers are designed to measure the spectral power distributions of illuminants. They operate almost like spectrophotometers in the visible region...

.

AATCC 183 should be used in conjunction with other related standards including American Society for Testing and Materials (ASTM) D 6544 and ASTM D 6603. ASTM D 6544 specifies simulating the life cycle of a fabric so that a UPF test can be done at the end of a fabric's life cycle – which is when most fabrics provide the most reduced level of UV protection. ASTM D 6603 is a consumer format recommended for visible hangtag and care labelling of sun protective clothing and textiles. A manufacturer may publish a test result to a maximum of UPF 50+.

While there is some correlation between the amount of visible light that passes through a fabric and the amount of UV that passes the same fabric, it is not a strong relationship. Based on some of the new-technology fibers and textiles designed for the sole purpose of UV blocking, it is not always possible to gain a good understanding of the UV protection level of a fabric simply by holding it up and examining how much visible light passes through the fabric.

Sun protective clothing and textile/fabric manufacturers are currently a self-regulating industry in North America, prescribed by the AATCC and ASTM methods of testing.

See also

  • Rash Guard
    Rash guard
    A rash guard, also known as rash vest or rashie, is a type of water wear, an athletic shirt made of spandex and nylon or polyester. The name rash guard reflects the fact that the shirt protects the wearer against rashes caused by abrasion. These shirts can be worn by themselves, or under a wetsuit...

  • Solar radiation
  • Sun
    Sun
    The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

  • Sun bathing
  • Sunburn
    Sunburn
    A sunburn is a burn to living tissue, such as skin, which is produced by overexposure to ultraviolet radiation, commonly from the sun's rays. Usual mild symptoms in humans and other animals include red or reddish skin that is hot to the touch, general fatigue, and mild dizziness. An excess of UV...

  • Sunglasses
    Sunglasses
    Sunglasses or sun glasses are a form of protective eyewear designed primarily to prevent bright sunlight and high-energy visible light from damaging or discomforting the eyes. They can sometimes also function as a visual aid, as variously termed spectacles or glasses exist, featuring lenses that...

  • Sunscreen
    Sunscreen
    Sunblock is a lotion, spray, gel or other topical product that absorbs or reflects some of the sun's ultraviolet radiation on the skin exposed to sunlight and thus helps protect against sunburn...

  • Suntanning
  • Ultraviolet
    Ultraviolet
    Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...

  • Umbrellas
  • UV index
    UV index
    The ultraviolet index or UV Index is an international standard measurement of the strength of the ultraviolet radiation from the sun at a particular place on a particular day...

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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