Über Sonnenschutz

Ultraviolet Radiation or UVR

The sun is our primary natural source of UV radiation. As an ionizing radiation it can cause chemical reactions, and causes many substances to glow or fluoresce. Most people become aware of the effects of UV through a nice sun tan or even the painful condition of sunburn. But the UV spectrum has many other effects, both beneficial and damaging, on human health.
Ultraviolet Radiation (UVR) is a major cause of skin damage. Ultraviolet rays are invisible and there is no direct correlation between temperature and UV exposure.
Ultraviolet radiation and Skin damage

Skin cancer

At this moment skin cancer is the most prevalent form of all cancers in Europe and the number of cases continues to rise. Skin cancer is the uncontrolled growth of abnormal skin cells. This rapid growth results in tumours, which are either benign (noncancerous) or malignant (cancerous).
There are three main types of skin cancer: basal cell carcinoma, squamous cell carcinoma and melanoma. Basal cell and squamous cell cancers are less serious types and make up 95% of all skin cancers. Also referred to as non-melanoma skin cancers, they are highly curable when treated early. Melanoma, made up of abnormal skin pigment cells called melanocytes, is the most serious form of skin cancer and causes 75% of all skin cancer deaths. Left untreated, it can spread to other organs and is difficult to control.


Ultraviolet (UV) radiation from the sun is the number-one cause of skin cancer.
Cumulative sun exposure causes mainly basal cell and squamous cell skin cancer. Episodes of severe sunburns before the age of 18, can cause melanoma in later life. Less common causes are repeated X-ray exposure and occupational exposure to certain chemicals.

UDF's Explained

The Ultraviolet Protection Factor is a scale created by the Australian Radiation Laboratory used to rate the Ultraviolet Radiation protection provided by materials. The term UPF was chosen to distinguish it from the SPF scheme for sunscreens, though the protective categories are directly comparable.
On a clear summer day in Spain, a person with unprotected fair skin can receive enough UVR to cause sunburn in 25 - 40 minutes. Wearing protective clothing (sombrero) or sunscreen or seeking safe shade, prolongs the time period before skin damage can occur.


An easy step towards protecting yourself and family from Ultraviolet Radiation is to erect shade. Shade comes in many forms with varying degrees of protection. It is important to know the level of protection.
It´s all in the fabric ! Let us advice you on the available fabrics and what protection it will provide.
Shade sails, or sun sails can act as a physical barrier to UVR. The UPF or amount of transmission depends on the amount of ultraviolet radiation that is absorbed by the fabric (eg the % of Ultraviolet Block out - UVB). That is: if the shade cloth is rated 50%, it absorbs 50 %, transmits 50 % and has a UPF rating of 2. If the shade cloth is rated at 90%, it absorbs 90%, transmits 10% and has a UPF of 10.  Shade cloth can provide UPF ratings up to 97% depending on the colour and fabric chosen.

Are there factors which can affect shade cloth fabrics?

Yes the weave, colour, stretch and quality of the fabric can have an influence on the level of shade that the sail will block.

•    Weave: Closely woven fabrics transmit less UVR than loosely woven fabrics.
•    Colour: Darker coloured fabrics tend to transmit less UVR than lighter coloured fabrics of the same type.
•    Stretch: The protection provided by fabrics susceptible to stretching varies considerably depending upon the tension. The bigger the stretch the lower the UPF.
•    Quality: Quality control in the production of the fabric is important. In poor quality cheap materials the measured UPF could vary as much as 30 to 40% at different places in the same piece of fabric.

The shade fabrics of our choice are made to high standards ensuring consistent and lasting levels of protection.
There are many shade fabrics available but their quality, and price, can vary considerably. Purchasing the right shade can be difficult, and at times confusing.

ACOOLA will ensure you that you get and maintain the properties you need!

What colour shade sail is cooler underneath?

White reflects heat, black absorbs it. Darker coloured fabrics are better at blocking UV rays than lighter ones. So a dark blue, green, or black would be better than yellow or white.

The black fabric is certainly going to be hotter to the touch, but since you are at least a meter under the sail it does not reflect the heat on your body.

What about reflection of the radiation?​

If you are in the shade but close to a reflective surface, such as a swimming pool, shiny white wall or white outdoor table, you may still be exposed to UV rays that bounce off these surfaces. Anything that causes a glare in the Sun (e.g. snow, water, white surfaces) has the potential to increase your UV exposure by reflecting and scattering radiation from any direction - including beneath the shade sail.