Which type of UV rays is blocked by the ozone layer and has germicidal properties?

The type of UV rays that is blocked by the ozone layer and possesses germicidal properties is UVC. UVC rays have the shortest wavelength and are known for their ability to kill bacteria and viruses, making them effective for disinfection purposes.

The ozone layer in the Earth's atmosphere serves a crucial role in absorbing a significant amount of UVC radiation, thereby protecting living organisms from potential harm. This natural barrier prevents UVC rays from reaching the surface of the Earth in substantial amounts, which is vital for maintaining ecological balance and health.

In contrast, UVA rays penetrate the skin more deeply and are primarily associated with skin aging and long-term skin damage, but they do not have germicidal properties. UVB rays are also absorbed by the ozone layer but not as completely as UVC and are mainly responsible for causing sunburn and contributing to skin cancer. Infrared rays do not fall within the ultraviolet spectrum and primarily contribute to warmth rather than providing germicidal effects.