Q. Consider the following pairs:
|1. UV-A||Blocked by typical window glass|
|2. UV-B||Completely absorbed by the Ozone layer|
|3. UV-C||Harmless to human beings|
|4. Titanium dioxide||Skincare products|
Pairs 1 is incorrect: A typical standard window glass, according to the International Ultraviolet Association, allows UV-A to pass through whereas almost 100% of the UV-B and UV-C light is blocked. Therefore, some UV light enters our home and potentially affects our skin. Some of these effects include increased freckles and sensitivity to sunlight which could result in rashes or photodermatitis.
Pairs 2 is incorrect: UV-B is mostly absorbed by the ozone layer but still gets through (about 5% gets through overall). It harms the top layer of your skin even just for 15 minutes of Sun Exposure. UVB rays age skin over time.
Pairs 3 is incorrect: UV-C is absorbed completely by the ozone layer. It is very harmful to people who are working with man-made sources of UV-C, like welding torches, mercury lamps, and germicidal UV lighting.
Pairs 4 is correct: Titanium dioxide (TiO2 ) and zinc oxide (ZnO) are the two most popular inorganic UV protective materials in skincare products.