The answer is yes, usually some UV rays do come through window glass.
You may think that you don’t need to worry about sun damage when you’re indoors, but that’s not true if you’re sitting in front of a window…..
This is a really important issue for anyone sitting in direct sunlight that comes through a window. Normal glass blocks all of UVB but allows UVA to come through. Both of these rays are harmful. Remember:
- UVB is considered the main sunburn ray
- It causes skin cancer and sun damage
- The SPF in a sunscreen tells you how well the product protects you from UVB
- Is the UV ray in tanning beds
- It penetrates the skin more deeply than UVB playing a big role in sun damage including wrinkles
- It can cause skin cancer
- The SPF on sunscreens tells you nothing about whether the product protects you from UVA. Look for sunscreens labeled ‘broad spectrum’ or that offer “UVA Protection”, but even then full UVA protection is more complex.
For clients who sit in direct sunlight coming in through window glass, We recommend wearing a minimum of 15 SPF sunscreen and clothing that blocks UV rays. If their windows claim to block UV rays I point out that a very tiny amount of UV still gets through. It’s possible to block 99.9% of UV rays, but even if their windows are that good, the 0.1% can add up at 8 hours a day, 5 days a week. Wrinkles, age spots and skin cancer just ain’t worth it!
For exposure through windows that don’t claim to block UV rays we advise our clients to re-apply 15 SPF sunscreen every 2 hours if they can’t move out of the direct sunlight. We also recommend that clients make their own shade, close the blinds, etc.
If you have any questions or concerns about skin care or skin health please continue to post them here.