Having studied marine chemistry, Ronan Jézéquel joined Cedre (Centre of Documentation, Research and Experimentation on Accidental Water Pollution) in 1997 for a long term voluntary internship which subsequently granted him access to a postgraduate course in Marine Chemistry.

Ronan Jézéquel was enlisted by Cedre in 1999 as a conscript, before joining the team in 2000 as a PhD student, then as an employee in 2003.

Ronan Jézéquel works for the Research Department, within which he is in charge of studies on the medium and long term behaviour of heavy oils. The different experiments (laboratory-based and in situ) which he has overseen have enabled him to acquire a certain expertise in the chemistry of oil and in analysis techniques demonstrating natural oil weathering processes (biodegradation, photoxidation). Since 2011, Ronan Jézéquel is also in charge of all In Situ Burning studies and experiments conducted at Cedre.

In addition to his work as a research engineer, Ronan Jézéquel has also been a member of the Emergency Response Team during 3 years as a first-line duty officer.