Mary Engle Pennington
Mary Engle Pennington was a pioneer in the safe preservation, handling, storage and transportation of perishable foods. A bacteriological chemist, food scientist and refrigeration engineer, she devoted most of her career to the study of refrigeration and its application to food freshness and safety. Her work has made a significant impact on the health and well-being of generations of Americans.
Pennington was born in Nashville, Tennessee, in 1872. She discovered her love for science at just 12 years old after reading Rand’s “Medical Chemistry,” a textbook she had borrowed from her local library. She asked the private girls’ school she attended to offer a chemistry course, but the school’s headmistress denied her request because she believed that chemistry was not a field for girls or women to study.
When Pennington turned 18, she enrolled at the University of Pennsylvania, where she earned a certificate of proficiency in chemistry and biology in 1892. At the time, the university did not award degrees to women. However, her academic record was so impressive, the university opted to admit Pennington to a graduate program. In 1895, she earned her doctorate in chemistry.
In 1905, Pennington joined the U.S. Department of Agriculture’s Bureau of Chemistry, which would later become the U.S. Food and Drug Administration (FDA). In 1906, she had the opportunity to apply for a position as chief of the Food Research Laboratory.
Initially she was hesitant to apply for the job because she knew it was unlikely a woman would be selected. Despite this, she took the civil service examination at the encouragement of Bureau Chief Harvey Wiley, who changed Pennington’s name to “M.E. Pennington” to conceal her gender. After achieving the highest possible score, Pennington was offered the job. She became the first woman to serve as the FDA’s lab chief in 1906.
Following the passage of 1906’s Pure Food and Drug Act, as lab chief, Pennington developed revolutionary standards for the safe processing of chicken and the safety procedures to help avoid bacterial contamination of milk. She researched and devised spoilage-free methods of storing and shipping poultry, eggs and other perishable foods, introducing methods that were adopted across the food handling industry. She also developed an efficient process for scaling, skinning, quick-freezing and dry-packing fish fillets immediately after the catch.
When the U.S. entered World War I in 1917, Pennington was assigned to future President Herbert Hoover’s War Food Administration (WFA). The WFA was an agency that had been created to maximize food production and conservation during the war. “We are at war…we need food…and that food must be saved,” Pennington said in a letter addressed to the St. Louis Railway Club in 1917.
Tasked with testing the storage and cooling systems of the nation’s 40,000 refrigerated railcars, Pennington experimented with different types of loading racks, ice bunkers and circulations systems to cool the cars evenly. Her research helped to establish national standards for ice-cooled refrigerator cars, set standards for construction and insulation, and solve the problem of humidity control in cold storage.
Pennington’s patented inventions include a poultry-cooling rack, a bacteria-resistant method of treating eggs and a sterile food products container. Later in her career, she oversaw the design and construction of commercial and home refrigerators.
In 1940, Pennington was awarded the Garvan Medal from the American Chemical Society, and in 1959, she became the first woman to be inducted into the American Poultry Historical Society Hall of Fame. Having spent more than 40 years improving upon the government’s understanding of food safety, Pennington was recognized in her time as the leading authority on the handling, transport and storage of perishable foods and the application of refrigeration. In 1947, she was elected fellow of the American Society of Refrigeration Engineers, where she was an active committee member and served as a contributor to the organization’s publications.
