People who work outdoors should avoid prolonged exposure to sunshine because of the damaging effects of ultraviolet (UV) radiation from the sun.

The UV levels are highest in spring and summer between 10 a.m. and 4 p.m. At noon on a clear summer day, for example, it can take only 15 minutes to cause a sunburn on unprotected fair skin.

To reduce the exposure of workers to ultraviolet rays while working in direct sunlight when UV levels are high, the following precautions are recommended:

• Wear a hat.
• Wear tightly-woven clothing covering as much of the body as is practicable.
• Apply sunscreen with a Sun Protection Factor (SPF) of 15 or higher on exposed skin. The sunscreen should be effective in filtering both UV-A and UV-B rays; this information is usually printed on the product's packaging.
• Wear eyeglasses that effectively filter ultraviolet rays. Plastic safety glasses and plastic cosmetic sunglasses have been found to be good UV filters. UV filtering factors appropriate for sunglasses used for different purposes are specified in the CSA draft Standard Z94.5, "Nonprescription Sunglasses."

For information on the CSA draft Standard Z94.5, please contact the Canadian Standards Association at (416) 747-4000 or write to 178 Rexdale Blvd., Rexdale, ON M9W 1R3.

Please photocopy Ministry of Labour Alerts, distribute them widely and post them where people will see them.

Produced by the Radiation Protection Service, Ministry of Labour

Alert 1/0394R Rev. 18/03/94. ISSN 1195-5228