BWStat is an excel tool designed to facilitate the implementation of the BOHS-NVvA Guidance. The tool allows the estimation of, from three or more measurements, group and individual compliance with the OEL, taking into account the intra- and inter-individual variation in repeated measurements from the same individuals, and measurements in different individuals from a similar exposure group. By following the BOHS-NVvA Guidance, BWStat is much more advanced than IHStat for example. Version 1 was launched during the NVvA conference 2013 and works using either Dutch, English, German or French. Version 2, additionally available in Spanish, was launched during the IOHA congress 2015 by means of a Personal Development Course at the start of the conference, and a poster during the conference. The tool was developed by Tom Geens (Provikmo & BSOH), Theo Scheffers (TSAC, NVvA & BSOH) and several other colleagues from Belgium and abroad. The presentation, the poster and the tool itself are free to download. A manual is under development.