Roger LTEIF was born in Lebanon on March 15, 1969. In 1994, he obtained his Master's degree in general chemistry at the Faculty of Sciences II, Lebanese University. In 1995, he obtained his Advanced Studies Diploma, DEA in Applied Chemistry and Industrial Process Engineering from Pierre and Marie Curie University-Paris VI.During his preparation of his doctoral thesis between 1995 and 1998, in Process Engineering - Chemistry and Electrochemistry of Functional Polymers at Paris Val de Marne University-Paris XII, he was a part-time teacher and then Temporary Teaching and Research Associate-ATER.In 1998, he was a quality manager in the industry PETCHEM - Zouk Mosbeh (Lebanon) and a part-time lecturer at the Faculty of Sciences of Saint Joseph University in Beirut. In 1999, he also held the position of part-time lecturer at the Faculty of Sciences of the Lebanese University, section II.In 2000, he joined the Faculty of Sciences of Saint Joseph University in Beirut as a lecturer and in 2008 he was promoted to the position of Associate Professor. During the period from 2002 to 2005, he took charge of the Master's degree in Industrial Technology and set up and directed the Master's degree in Food Chemistry. Between 2006 and 2012, he was Director of the Chemistry Department at the Faculty of Sciences of Saint Joseph University in Beirut.Since joining the Faculty of Sciences at Saint Joseph University in Beirut, he has formed the research team “Kinetic Studies in Heterogeneous Media” where he has supervised several doctoral theses in collaboration with several universities in France. His main research areas are food chemistry, cement chemistry and cosmetics.He is the author of around sixty scientific publications in international peer-reviewed journals and has participated in several national and international conferences.In 2011, he obtained the Diploma of Habilitation to Direct Research (HDR) in “Process and Environmental Engineering” at the National Polytechnic Institute of Toulouse (INPT).In 2012, he was appointed Professor at Saint Joseph University in Beirut. During the same year, he became a sworn chemist expert before the courts in Lebanon.In September 2013, he was appointed Executive Director of the Health Technology Pole (PTS) of Saint Joseph University in Beirut and member of the executive committee of the Lebanese Association for the Advancement of Sciences (LAAS).In September 2014, he was appointed Coordinator of the scientific commission at the Science and Technology Campus of the Research Council of Saint Joseph University in Beirut.In November 2015, he was awarded the Excellence in Scientific Research Award, 2015 (5th edition), for his research work in the field of “Development and safety of the food industry”. This event was organized by the National Council for Scientific Research in Lebanon (CNRS), under the patronage of the Lebanese Prime Minister, Mr. Tamam Salam.In 2023, he was appointed member of the Scientific Orientation Council-COS of the School of Industrial Biology (EBI), Cergy-France.