Ultraviolet light is invisible to the human eye but is very important for life. Our bodies use it to make vitamin D, but too much exposure can cause painful burns and even cancer. Although UV light can be dangerous, it is also very valuable and is used in many ways.

UV is also important to plant growth.

UV light is broken up into three sections.

UV consists of three sections within the electromagnetic spectrum.
UVA = 400nm-315nm
UVB = 315nm-280nm
UVC = 280nm-100nm

Natural sunlight produces these three sections of UV. However, UVC is not naturally present on earth because the Earth’s atmosphere blocks the extremely harmful light from reaching the Earth’s surface.

Lighting sources can artificially produce all three types of UV, however the components used to construct the light source, such as glass, will generally block UV emitted from the light. Check the spectral distribution chart on your grow lamps packaging to see if your light is producing any UV.