Slip and Fall Expert Witness
John C. Sotter
President
Consultant and Expert Witness — Slip, Trip and Fall
SOTTER ENGINEERING CORPORATION
26705 Loma Verde
Mission Viejo, CA 92691-6055
TELEPHONE/FAX: 949-933-6971
Email: John.Sotter@SafetyDirectAmerica.com

Curriculum Vitae
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President John C Sotter graduated from the University of California at San Diego in 1992 with a Bachelor of Arts in Urban Planning. His studies there included work in floor friction and in chemistry.
He has 17 years of experience in responsible safety work for the City of San Clemente, California.
He has trained in floor slip resistance testing in the U.S. and the U.K. (including pendulum and Tortus manufacturing facilities) and has done most of Sotter Engineering’s floor slip resistance testing work for the past twenty-five years, doing testing for more than 1,000 individual clients, both in our laboratory and in the field from Hawaii to Maine, British Columbia to Mexico, New York to Florida, on the high seas, and everywhere in between. He has tested floors and road surfaces for some of the world’s largest international corporations.
John’s twenty-five years of extensive experience with floor slip resistance testing using the British Pendulum Tester, Tortus digital tribometer, SlipAlert, BOT-3000E, and ASTM C1028 static friction test device, is unmatched both in the United States and in the Americas. He has worked in floor friction testing and floor friction treatment in the USA, Canada, Mexico, and on the high seas. He helped develop an anti-slip floor coating that has now been sold in dozens of countries.
John has testified in court once, has been deposed five times, and took part in two mediations. He has worked with somewhere around a hundred lawyers on slip and fall lawsuits, almost all of which were settled before deposition or trial was required. This is due in large part because John uses internationally-accepted and peer-reviewed science, and he is very knowledgeable about the withdrawn, expired and unreliable test methods used by most American slip and fall “experts”. Unlike most slip and fall expert “liars for hire”, John works for architects, building owners and flooring manufacturers to help eliminate slips on properties. He doesn’t just hang out outside courthouses in a suit waiting to fool juries with debunked and junk science that has been shown to lack precision in multiple research studies.
He works behind the scenes with lawyers to get the testimony from unscrupulous experts with their unreliable instruments and data thrown out of court. Settling a lawsuit when one expert is presenting internationally-accepted testing data from a test device with a peer-reviewed, published test method in over 50 nations, and the other is using an old, withdrawn American standard with well-documented poor precision (or an instrument with no published test method at all in any nation) can be quick and easy.
John’s background includes many miles barefoot on wet surfaces: years of competitive swimming, international sailing, water polo (a high school All-American), and surf lifeguarding. John has traveled extensively in 25 nations.
He recently made substantial revisions and updates to the American slip and skid resistance test method – ASTM E303-22 – which was published through the ASTM in June of 2022. It is the most reliable and useful floor slip resistance test method ever published in the USA. He is also a full member of the United Kingdom’s Slip Resistance Group (UKSRG), who does research into slips and falls to prevent slips, and helps create slip resistance test standards for European nations.
John’s participation in several slip resistance proficiency tests, which included slip resistance testing labs in several nations testing identical surfaces, has proven that John is one of the most precise slip resistance testers in the world today, if not THE most precise.
John has been instrumental in educating architects, building owners, flooring manufacturers, other experts in this field of science, and attorneys on the fake slip resistance test methods that have been published and then eventually withdrawn (or allowed to quietly expire) by the American Society for Testing and Materials (ASTM), the National Floor Safety Institute (NFSI), and the American National Standards Institute (ANSI) over the years.
John has published websites, blog posts and videos helping people understand that there is internationally-accepted and well-researched science in the field of testing of floors for slip resistance to help stop preventable slip injuries, and there are American “non-profit organizations” that publish garbage tests to help unscrupulous flooring and coatings companies make a quick buck, and help win multi-million-dollar lawsuits using unproven tests used nowhere outside of American courtrooms. The list of garbage tests used to fool unsuspecting American tile consumers and juries over the decades, such as ASTM D2047 (which measures how slippery a clean and dry floor is to someone standing still on it), grows longer and longer each year.
John calibrates pendulum testers after having been trained to do so in the United Kingdom by a major pendulum manufacturer there. He has now calibrated pendulums for private corporations and governmental agencies in several countries.
PUBLICATIONS: “Specifying Anti-Slip Floor Coatings”, March 2020, pg. 24
“The New Slip Resistance Requirements in IBC,” July 2016, pg. 72.
Numerous educational blog posts published at https://safetydirectamerica.com/author/johnsotter/
Numerous educational videos published at https://www.youtube.com/user/safetydirectamerica/videos
J. GEORGE SOTTER, P.E., Ph.D.
Engineering Consultant — Slip, Trip and Fall
SOTTER ENGINEERING CORPORATION

Curriculum Vitae
Download his full Curriculum Vitae
Academic Background: Ph.D., University of Sheffield, England
B.S., Pennsylvania State University
Recent Experience: Consultant/expert witness in slip/trip and fall litigation; experience in locations ranging from Japan and Guam to Bermuda. Project Manager and Principal Investigator of OSHA-driven one-man-year project to minimize slipping incidents on construction-site steel products. Laboratory and field testing of pedestrian surfaces for slip resistance. Consultant to Carnival Cruise Lines in slip reduction
Professional Affiliations: Member of eight national organizations, in two nations, relevant to slip resistance affiliations of pedestrian surfaces. Chairman, Ceramic Tile Institute of America’s Slip Resistance Committee
Member of American Society for Testing and Materials (ASTM) and American Society of Mechanical Engineers (ASME)
Publications: Book, STOP Slip and Fall Accidents! 203 pp., Sotter Engineering Corporation, 2000, www.amazon.com, ISBN 0-9676030-0-5
“Specifying Anti-Slip Floor Coatings”, March 2020, pg. 24
“How to Buy Flooring Having Sustainable Slip Resistance,” The National Hotel Motel Engineer Association magazine, Winter 2011
“How to Buy Flooring Having Sustainable Slip Resistance,” U.S. Government’s Center for Disease Control, NIOSH International Conference on Fall Prevention and Protection 2010 in Morgantown, WV on May19, 2010.
“Resonant Combustion in Rockets,” Scientific American, December 1968
Author of over 35 papers, articles and other publications in technical trade magazines, international symposia, and archive journals. Includes several addressing pedestrian falling accidents
Registrations, Certifications: Licensed as a Professional Engineer (Chemical) by State of California Board for Professional Engineers and Land Surveyors (current, since 1971), and (on as-needed basis) five other states.
Experience: More than 50 years in consulting and engineering. Slip-and-fall forensic consulting for both plaintiff and defense, in roughly equal proportions.