Sunlight contains three types of ultraviolet (UV) rays:

  • UVA or ultraviolet A rays
    Most of the natural light we see is made up of UVA rays, which can penetrate deep into our skin and cause wrinkles and aging.
  • UVB or ultraviolet B rays
    These rays are most damaging to our skin and are the main cause of sunburns.
  • Ultraviolet C rays (short-wave radiation)
    Earth’s atmosphere prevents short-wave radiation from reaching us.

Any sun exposure can lead to premature aging of the skin or skin cancer.

What causes sunburns?

You develop a sunburn when your skin is overexposed to UV rays.  The amount of time it takes to become overexposed varies widely between people.

UV rays can get through clouds, fog and haze. Water, sand, concrete and especially snow can reflect, and even increase, the sun’s burning rays.

What are the signs of sunburn?

Your skin will redden. Depending on the severity of the burn, blisters may appear as well.

How can you protect yourself from the sun?

  • Cover up. If you have to be outside, make sure to cover up with a hat, long-sleeved clothing, or umbrella.
  • Seek out shade. Avoid the sun between the peak hours of 11 a.m. and 4 p.m.
  • Schedule outdoor activities around peak hours.
  • Use a good quality sunscreen with a minimum SPF of 15 (30 is better) year round.
  • Wear sunglasses to protect your eyes.

Canadian Centre for Occupational Health & Safety
Canadian Cancer Society

For more information on working under hot conditions, see the WorkSafe publications, Working Under Hot Conditions and Hot Conditions Guidelines, below:

Working Under Hot Conditions
Hot Conditions Guidelines