Chief van Loben Sels began his career with CAL FIRE in 1993 as a Firefighter I in the Fresno-Kings Unit. In 1995, he promoted to Fire Apparatus Engineer in the Madera-Mariposa-Merced (MMU) Unit. In 2000, he accepted a TAU Fire Captain position in the San Benito-Monterey Unit, and in 2001, promoted to Fire Captain in MMU.

In 2006, Chief van Loben Sels promoted to Battalion Chief in the Santa Clara Unit (SCU) Training Bureau, and in 2008, assumed the SCU Headquarters Battalion Chief position. In 2010, he transferred back to MMU where he was responsible for the Los Banos Battalion.

Chief van Loben Sels promoted to MMU Deputy Chief of Operations in 2017. In 2018, he was assigned as the MMU acting Unit Chief and accepted the permanent appointment in 2019. As the MMU Unit Chief, through cooperative fire protection agreements, he served as the Fire Chief for the counties of Merced, Madera, and Mariposa and the cities of Atwater and Madera.

From 2004 through 2020, Chief van Loben Sels served on CAL FIRE Incident Management Teams (IMT) and was the Incident Commander of CAL FIRE IMT 1. He serves on the CAL FIRE Incident Management Team Committee, is the National Association of State Foresters Western Region Representative and is a cadre member for the Complex Incident Management Course (CIMC) which teaches advanced incident management throughout the United States. He has also taught on numerous CAL FIRE cadres including Incident Management III (C-400), Operations Section Chief, and Incident Commander.