UV Protection Factor (UPF) of Textiles

Over exposure to ultraviolet radiation (UVR) from the sun has raised considerable public health concerns. Consumers have an increased awareness of skin cancer, eye damage (such as cataracts) and premature skin aging and as a result they are looking for protection beyond sunscreens such as lotions and creams.

Depletion of the ozone layer, which protects the earth’s surface from harmful UVA, UVB and UVC rays, has forced the need for additional protection. UVA and UVB are the two classifications for solar radiation hitting the earth’s surface.

Dangers and Types of UV

UVA wavelengths are between 315 and 400 nm and are most abundant at the earth’s surface. Exposure to these rays results in premature aging, wrinkling and has been implicated as a cause of skin cancer.

UVB wavelengths are between 280 and 315 nm and are more dangerous than UVA rays however less of them reach the earth’s surface as most are absorbed by the ozone layer. UVB rays are a major cause of sunburn, skin cancer and cataracts.

The third type, UVC wavelengths are between 100 and 280 nm and are extremely dangerous but they do not reach the earth surface due to their absorption by the ozone layer.

Clothing can provide a barrier against harmful rays, however, it is important to understand that not all fabrics and garments offer equal protection. There are several international UPF test standards available. The protection offered by fabrics against UVA and UVB can be determined according to these standards.

Comparison of UPF test standards are summarized in a table within the latest SafeGuards bulletin (http://newsletter.sgs.com/eNewsletterPro/uploadedimages/000006/sgs-safeguards-15113-uv-protection-factor-upf-of-textiles-a4-en-13.pdf).

Factors affecting UPF of textiles

- Fiber composition, some types of fibers absorb more UV light than others
- Fabric construction, especially thickness, weight and porosity
- Fabrics in dark colors are usually more effective in blocking UV
- Optical brightening agents can absorb UV and emit visible light

Remarks:

(1) ASTM D6544 standardized the exposure procedures prior to UV transmission testing of the fabric or garment. The exposure conditions include 40 cycles of washing, 100 AATCC Fading Units of simulated sunlight, and chlorinated water for swimwear which relates to approximately two years of seasonal use.

(2) For labeling details, please refer to details in AS/NZS 4399, EN 13758-2, and ASTM D6603.

(3) According to ASTM D6603, the UPF value on the product label should be the lowest UPF value among the results of “unprepared (original)”, “laundered-once” (for products with care label “Wash once before wearing”) or “prepared-for-testing (as per exposure conditions in ASTM D6544)” specimens.

About SGS Softlines Services

Through a global network of laboratories and offices, SGS offers a range of functional testing as well as other regulatory and safety testing (http://www.sgs.com/en/Consumer-Goods-Retail/Softlines-and-Accessories/Textile-and-Clothing/Testing.aspx) for a range of international markets.

Please feel free to contact the SGS experts for more information.

SGS is the world’s leading inspection, verification, testing and certification company. SGS is recognized as the global benchmark for quality and integrity. With more than 75 000 employees, SGS operates a network of over 1 500 offices and laboratories around the world.

SGS Consumer Testing Services
Kris Wan
Senior Manager, Global Softlines Development Office
SGS Hong Kong

t: +852 2334 4481
Email: cts.media@sgs.com
Website: www.sgs.com/softlines

This release was published on openPR.