Sun Safety

While some exposure to sunlight may be acceptable, too much can be dangerous. Prolonged exposure to ultraviolet (UV) radiation from the sun can result in sunburns or lead to serious health effects such as premature aging of the skin and skin cancer.

Outdoor workers are exposed to ultraviolet (UV) radiation from sunlight and should take preventive measures to protect themselves.

Preventative Measures to Protect from UV Radiation

  • Apply a broad spectrum sunscreen with UVA and UVB protection and a sun protection factor (SPF) of 30 or higher to all exposed skin 
    • Apply the sunscreen 20 minutes before sun exposure to allow time for it to absorb into the skin.
    • Reapply every 2 hours or more often if you are sweating heavily or swimming.
    • Apply sunscreen even on overcast days, as cloud cover offers little protection from UV radiation.

Broad spectrum sunscreens are available in the Guelph Campus Physical Resources Stockroom and can be ordered by any administrative or academic unit.

  • Use lip balm with sunscreen.
  • Cover your skin. Preferably, wear long-sleeved shirts, long pants and a wide brim hat when outdoors for periods longer than 30 minutes.
  • Wear sunglasses that protect against UV rays.  Look for sunglasses that block 100% of UVA and UVB radiation.
  •  Exposure to UV rays is strongest between 11 am and 4pm.  If you have to spend time outdoors during these hours take extra precautions. Apply sunscreen more frequently and take breaks in the shade, in particular at midday when sunlight is the strongest.   
  • Protect yourself from exposure to indirect UV rays that are reflected from water, white sand, concrete, snow and ice.

UV Index

The UV Index from Environment Canada measures the intensity of UV radiation under sunny and light cloud cover conditions. The index is given as a number in one of five categories from Low (0-2) to Extreme (11+). The higher the UV Index, the more damage that can be done to your skin and eyes. In general, when the UV Index is 3 or higher, take precautions to protect your skin.

For the daily UV Index forecast in your region refer to Environment Canada’s Canadian Daily UV Index Forecast.

For more information or if you require assistance:

If you require assistance or have any questions on the selection of appropriate preventative measures for reducing UV radiation exposures in your work area, contact the Occupational Hygienist, Bryan Lee at at 519-824-4120 ext. 54855 in Environmental Health and Safety.

Links to additional useful resources:

NIOSH Fast Facts: Protecting Yourself from Sun Exposure. DHHS (NIOSH) Publication Number 2010-116. National Institute of Occupational Safety and Health (NIOSH). April 2010. Accessed 2017-12-07
Skin Cancer and Sunlight: OSH Answers. Canadian Centre for Occupational Health and Safety (CCOHS). Accessed 2017-12-07
Sun Safety – Skin Cancer. Centers for Disease Control and Prevention. Accessed 2017-12-07