Personal Safety Personal safety of less self reliant users – Lieuwe de Witte and Ruud van Herpen Posted July 20, 2019 Daphne Stockton Lieuwe de Witte, IFV en Ruud van Herpen, Nieman Raadgevende Ingenieurs. Videotaped at the International Congress Fire Safety & Science on November 14 as well as 15, 2018 at the Institute for Safety (IFV) in Arnhem, the Netherlands.