Nippon Sheet Glass (NSG) is developing a new range of UV-cut automotive glass product called UV Protect 400 which blocks 99% of UV rays (300nm-400nm), which includes the longer wavelength UVA (315nm-400nm) that can cause damage to deeper layers of the skin. The new technology can be used in all car windows and is said to be the world's first automotive glass to block UV radiation of up to 400nm wavelength by 99%.
Current car glass products that can block 99% of sub-380nm UV ray transmittance are already available and becoming a standard feature for light vehicles sold in Japan. The NSG Group, however, has focused on effectively blocking the longest-wavelength range of UV, 380nm-400nm, which can penetrate into deeper layers of the skin.
The portion of sunlight with wavelength shorter than 400nm is called ultraviolet radiation. UV rays are further divided into UVC (-280nm), UVB (280nm-315nm), and UVA (315nm-400nm). UVA and UVB reach the surface of the earth. The surface of human skin may become hot or red by contact with UVB, causing sunburn and ages spots. UVA penetrates deeper into the skin, causing skin to sag and develop wrinkles. Recently the protection against photoaging – UV rays' skin-ageing effect – is considered important.