Clothes marked with "UV-protection" certification tags are increasingly being seen on retailers' shelves and clothing racks in Finland.

The country's skin cancer rate is among the highest in the world. According to the World Cancer Research Fund, Finland ranked tenth in terms of age-standardised incidence rates of skin cancer.

Damage caused by the sun is often the cause of melanoma of the skin, which is the 17th most common type of cancer globally, according to the World Cancer Research Fund International.

However, while there are agreed standards of UV protection in clothes, there is no official certification and products are not monitored by a third party in the EU.

According to a shop assistant at clothing retailer Lindex in the western city of Vaasa, UV-protection rated clothing is popular, particularly in the children's swimwear section.

Customer UIla Aho, who was at Lindex with her children, said she always picks clothing marked with UV labels over ones that aren't.

"If the clothes have sun protection, we absolutely buy them. It's very important," Aho told Yle.

However, since UV-protection certification is not standardised, the labels do not offer much information to consumers.

The EU is currently mulling increased regulations of the UV-protective clothing market, but any rule changes could take several years.

In any case, people do not necessarily need to choose UV-protection marked clothing to protect themselves from the sun, according to Carl Kyrklund, a skin disease specialist at the Helsinki Skin Hospital.

How protective a garment is against skin damage from the sun mostly depends on how thick the clothing is and how much light is let through it.

"You can put the garment up to a light to see how much it lets through," Kyrklund explained.

However, UV-rated swimwear can differ, Kyrklund said, noting that the protective qualities of bathing suits are tested.

"The UV protection offered by similar artificial fabrics is usually good, even when they get wet," he said, adding that non-UV rated swimwear can be just as protective as ones with the rating, and that it depends on the type of material.

The difference between regular clothes and garments with UV protection tags is that the latter group actually undergo tests.

Some UV-rated clothing is chemically treated, but doing so is not necessary to earn garments an Ultraviolet Protection Factor (UPF) rating.

"A regular piece of clothing offers some protection against UV radiation, but the materials, fibre and density all affect how well it protects against UV radiation," said Riikka Väänänen, Senior Officer at Finnish Safety and Chemicals Agency (Tukes).

EU law states that fabrics need to be tested and found to have an UPF rating of at least 40 in order to be marketed as offering UV protection.

While the UV-protection clothing industry uses different test standards, there is no actual certification of the products by a third party, Väänänen noted.

"So, even if products have the same UPF rating, depending on the test standard, the clothing may need different [chemical] pre-treatments, which means that the products aren't completely comparable," Väänänen explained.

Questions about UV-protection in clothes are being examined at the EU level, and it is possible that rules on the matter could change in the future.

However, when that might happen is up in the air, but could take several years, according to Pirje Lankinen, Ministerial Adviser at the Ministry of Social Affairs and Health.

In 2016, the EU stipulated that sun-safe clothing would be classified as personal protective equipment (PPE) and subject to certain regulations, according to Intertek, an inspection testing and certification firm.