ultraviolet

https://doi.org/10.1351/goldbook.UT07492
Region of the electromagnetic spectrum extending from about \(100\ \text{nm}\) to \(400\ \text{nm}\). This region is divided into four sub-bands as follows:
Vacuum Ultraviolet (VUV)\(100\ \text{nm}\)–\(200\ \text{nm}\)
UV-C\(200\ \text{nm}\)–\(280\ \text{nm}\)
UV-B \(280\ \text{nm}\)–\(315\ \text{nm}\)
UV-A \(315\ \text{nm}\)–\(400\ \text{nm}\).
Note:
The notation and the limits of the various regions are as recommended by the International Commission on Illumination (CIE), with the exception that in these recommendations the UV-C range is \(100\ \text{nm}\)–\(280\ \text{nm}\), including thus the vacuum UV range.
Source:
PAC, 2007, 79, 293. (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 437 [Terms] [Paper]