Sun Safety
Ultraviolet Protection Factor

The ultraviolet protection factor (UPF) is a scale that rates the protection that cloth materials provide. A UPF rating is based on the percentage of ultraviolet radiation (UVR) that is transmitted through the material. Whenever possible, try to select a shade cloth that absorbs at least 90% UVR. No fabric provides 100% protection against UVR.

Factors that affect UPF rating of fabrics:

• The tighter the weave, the higher the UPF. When fabric is stretched, the tightness of the weave decreases, resulting in more UVR transmission
• Thicker fabrics have a higher UPF than thinner fabrics
• When fabric gets wet, UPF can decrease dramatically. Wet cotton can lose up to 50% of its UPF
• Dark colours are more protective than light colours

Products that have been tested are labelled, indicating the protective factor as an ultraviolet protection factor, or UPF. labelling is not mandatory, so for products that do not indicate a UPF, consider factors that affect UPF.

Amounts of UVR absorbed and level of protection