A study by Gambichler et al has confirmed that the Merino fibre offers high natural UV protection compared to many other fibres including cotton.

Not all clothing offers protection

Depletion of the ozone layer has made protection from the sun’s harmful radiation more important, and most people are now aware of the need to wear clothing to help prevent the development of disfiguring or life-threatening skin cancers. However, it’s been found that some fabrics provide insufficient ultraviolet (UV) protection.

Gambichler study parameters

In 2001, Gambichler, Rotterdam, Altmeyer and Hoffman investigated 236 apparel textiles to determine their UV protection factor (UPF). The fabrics were provided by a leading European garment manufacturer and the mean weight of the samples was 158 g/m2. They were investigated unstretched and in dry condition, and, in accordance with the European standard, the UPFs were determined spectrophotometrically. For each sample of fabric, a mean UPF value was calculated and rated as follows: 0+ (UPF <5); 5+ (5≤ UPF < 10); 10+ (10≤ UPF < 15); etc … 50+ (UPF ≥ 50).

UPF of most fabrics < 30

The results of Gambichler’s study showed that 33% of fabrics had a UPF < 15 and 19% had a UPF ≥ 15 and < 30, meaning more than half of the fabrics failed to satisfy the European standard for UV protective clothing of UPF 30+.

Performance of common fabrics

Many fabrics commonly worn in summer performed poorly in the test. Of the cotton samples, for example, 79% had a UPF ≤ 20 while 100% of the linen samples fell below the standard of UPF 30+. Many of the synthetics fared poorly also with 89% of the viscose samples failing the test.

Merino – superior natural UV protection

Only one apparel textile in the study had all its samples pass the test, and that fabric was Merino. In fact, Merino’s poorest sample produced a result of UPF 40+, while more than 70% of the Merino samples had a UPF ≥ 50+.

Summary

There is growing awareness of both the dangers of skin cancers and the disparity in the UV protection afforded by different fabrics and garments. A study by Gambichler et al in 2001 found that while cotton, linen and viscose frequently offered poor UV protection, Merino satisfied the European standard in 100% of cases, and more than 70% of the Merino samples produced the highest possible result of UPF ≥ 50+.