How Did Mary Engle Pennington Revolutionize Food Safety?

Have you ever wondered how everyday food became safe to eat? National Inventors Hall of Fame^® Inductee Mary Engle Pennington played a crucial role in making everyday food safer to eat, especially through advances in refrigeration. As a pioneering scientist and food safety expert, she revolutionized how food is managed, stored and preserved. Her work helped set the standard for standards that still protect consumers today. 

Early Life, Education and Influences

Pennington was born in Nashville, Tennessee, in 1872. From an early age, she showed a strong interest in learning, especially in chemistry and biology. Despite limited opportunities for women in science at the time, she became inspired to apply scientific knowledge to real-world problems. She studied at the University of Pennsylvania and became one of the first women to receive a doctorate in chemistry in 1895. This academic training prepared her for a career in scientific research and public service. 

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). Encouraged by bureau chief Harvey Wiley, she took the civil service exam and applied for the position of lab chief at the USDA Food Research Laboratory. She submitted her application under the initials M.E. Pennington. 

After receiving the highest possible score, Pennington was offered the job. She became the first woman to serve as the FDA’s lab chief in 1906.

Career, Achievements and Recognition

As lab chief, Pennington built a remarkable career as a chemist, microbiologist and public health leader at the Department of Agriculture. In her lab, she studied how milk, eggs and meat spoiled, and she identified the exact temperatures at which bacteria grew, solving the mystery of why food went bad so quickly. Her research on food storage, refrigeration and sanitation led the USDA to establish improved refrigeration and cleaner food handling practices nationwide, enforce food inspection laws and dramatically improve public health standards.

She received major awards and honors, including a Notable Service Award from President Herbert Hoover in 1919. Earning her this award was her significant contributions in the safe handling and transport of food in World War I. She personally inspected refrigerated railcars to ensure perishable foods reached troops safely, thus greatly strengthening the U.S. military’s food supply system.

Pennington earned five patents for her work in refrigeration and food preservation. Her 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 also oversaw the design and construction of commercial and home refrigerators.

 In 1940, the American Chemical Society presented Pennington with the Garvan Medal, one of the highest recognitions for chemists. 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. She also became the first woman elected to the Poultry Historical Society Hall of Fame in 1959. 

Pennington’s awards and honors reflect her pioneering work in food safety standards and her enduring public service contributions. 

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