Publication on a case report of chemical injury on the right cheek of a worker following exposure to 70% hydrogen fluoride during a valve opening. The immediate pain felt by the victim disappeared during washing with a solution of DAP HEXAFLUORINE®. Only a light painless erythema developed, justifying the application of calcium gluconate on the following day but did not require a work loss. Cyrille-Lazare Siéwé3, Jean-Marc Barbe4, Laurence Mathieu1, Joël Blomet1, Alan H. Hall2. 1Laboratoire Prevor Laboratory, Valmondois, France; 2Toxicology Consulting and Medical Translating Services, Inc., Laramie, WY, USA and Colorado School of Public Health, Denver, CO, USA; 3 affilié avec le Laboratoire Prevor, Valmondois, France et son affiliation actuelle est Programme des Nation Unies pour l'Environnement (PNUE), Division Technologie, Industrie et Economie (DTIE), Direction des produits chimiques, Genève, Suisse 4Cristalleries d’Arques, Arques, France