who we are
PSI was founded in 2014 to provide field verification, engineering peer reviews and consulting services to the cannabis extraction industry. We have extensive experience spanning across the nuclear, chemical, pharmaceutical and oil & gas industries.
Our cannabis engineering consultants have more than 155 combined years of industrial experience and have performed more than 1,800 extraction-related consultations. Currently operating in 34 US states and 5 countries, we are proud to offer the fastest and most rigorous third-party engineering reviews in the cannabis extraction industry.
Chris Witherell, PE
Chief Executive Officer
Chris has more than 25 years of experience in equipment design engineering, design verification, project engineering, and engineering management using ASME NQA-1 quality programs for commercial nuclear power and Department of Energy clients. He is a founding partner of Pressure Safety Inspectors, LLC. Chris has a Bachelor of Science in engineering with a mechanical specialty from Colorado School of Mines. He is a licensed Professional Engineer in Arizona, California, Colorado, Florida, Hawaii, Maine, Massachusetts, Michigan, Minnesota, Nevada, Ohio, Oregon, Tennessee, and Washington.
John R. Andrzejczak, PE
John has more than 35 years of experience engineering custom research and process equipment for the chemical, petrochemical, nuclear, and pharmaceutical industries. John’s Process Safety Management (PSM) experience includes facilitating and scribing Process Hazard Analyses using HAZOP, and developing PSM systems for process plants and Safety Analysis Reports for nuclear facilities. As quality assurance manager, he wrote, implemented, and maintained ASME Boiler and Pressure Vessel and ASME NQA-1 quality assurance programs. He is a licensed Professional Engineer in Colorado, Idaho, Maryland, New York, Pennsylvania, South Carolina, Tennessee, Texas, and Washington.
Vice President, Business Development
Greg has more than 34 years of experience in fuel controls for electrical power generation equipment and compressed natural vehicles, has developed notable utility scale thermal energy storage projects, and designed and lives in a close to Net Zero home. Greg has a Bachelor of Science Degree in Electrical Engineering from DeVry University and is a Colorado native. For PSI, Greg focuses on business development and customer relationships with extraction equipment manufacturers, processors, and Authorities Having Jurisdiction for the cannabis industry. Greg is passionate about his work and enjoys assisting PSI clients to achieve their business objectives.
Brad has more than 25 years of experience in industrial processes within the petrochemical industry. Brad graduated from the Colorado School of Mines with a Bachelor of Science in Petroleum Engineering. He was a co-founder of Bladestone, a consulting company that offered rig supervision and specialized in well control training to the oil & gas industry. Bladestone consulted for companies such as BHP and Encana.
Sarah Kaiman, CIH
Senior Industrial Hygienist
Todd LaBerge, PE
Fire Protection Engineer
Field Service Technician
Field Service Technician
“Crazy fast response and Field Verifications. This is an insanely huge step for our company and it’s all thanks to you.
Can’t wait to use your services again in the future!”