Lloyd A. Hall 1894–1971

Chemist

During his long and distinguished career in industrial chemistry, Lloyd A. Hall devised creative solutions to a host of challenging problems in the new and expanding field of food technology. His “flash-dried” salt crystals, introduced in the 1930s, combined the preservative effect of sodium chloride with the curative action of sodium nitrate and sodium nitrite. Far superior to any products then available, they helped to revolutionize the meat-packing industry. Hall also introduced the use of antioxidants to prevent spoilage of fats and oils in bakery products, and later pioneered a special process that used ethylene oxide gas to control the growth of molds and bacteria in spices, gums, and cereals.

Variations of the process, known as Ethylene Oxide Vacugas treatment, were later used to sterilize disposable hospital goods, in aseptic packaging for dairy and pharmaceutical products, and in the treatment of cosmetic powders, eye makeup, and baby talc. Another product Hall helped develop was hydrolyzed plant protein, which proved a versatile and highly effective food flavor fortifier. Over the years he was granted more than 100 patents for processes used in food manufacturing and packaging.

Chief chemist, director of research, and technical director of Griffith Laboratories, Inc. in Chicago, Hall was the first black man to hold a position of such prominence in a major industrial company in the United States. He arrived at Griffith Laboratories in 1925, following a brief stint as a consultant, and remained there until his retirement in 1959. During this time he completed his most important work in food chemistry and helped build the company into a major force in the food-processing industry. In 1939, he helped found the Institute of Food Technologists, the first professional organization serving chemists involved in food processing and preservation. Hall also worked as a consultant for the Food and Agriculture Organization of the United Nations, and was the first black person to serve on the board of directors of the American Institute of Chemists.

Hall was born in Elgin, Illinois, in 1894. His father was a Baptist minister and his paternal grandfather was founder and first pastor of the Quinn Chapel A.M.E. Church, Chicago’s first and oldest black church. He first became interested in the sciences in high school, where, as one of only five black students, he excelled in both his academic work and extracurricular activities. Upon graduating in 1912, he received four scholarships to study at Illinois universities. He enrolled at Northwestern and graduated with a B.S. in pharmaceutical

At a Glance…

Born Lloyd Augustus Halt June 20, 1894, in Elgin, IL; son of Augustus, a minister, and Isabel Hall; married Myrrhene E. Newsome, 1919; later adopted two children; died January 2, 1971, in Altadena, CA. Educa-Hon: Northwestern University, B.S., 1916; attended University of Chicago.

Chicago Board of Health, senior chemist, 1916-17; John Morrei! Company, chief chemist, 1919-21; Boyer Chemical Laboratory, chief chemist, 1921-22; Chemical Products Corporation, president and chemical director, 1922-25; Griffith Laboratories, chief chemist and director of research, 1925-46, technical director, 1946-59; George W. Carver Foundation, consultant, 1946-48. Served as a consultant to the United Nations Food and Agricultural Organization.

Memberships: NAACP (member of Chicago Executive Committee, 1932-34), Chicago Urban League (member of board of directors, 1935-36), Institute of Food Technologists (charter member, 1939; executive board member, 1951-55), U.S. Army Quartermaster Corps (member of Science Advisory Board on Food Research, 1943-48), Illinois State Food Commission (1944-49), Food Technology Council of the Illinois institute of Technology (1948-55), Chicago chapter of the American Institute of Chemists (chairman, 1954; member of the national board of directors, 1955), American Chemical Society, American Institute of Chemists (fellow), American Food for Peace Council.

Awards: Honor Scroll, Chicago Chapter, American Institute of Chemists, 1956; Honor Award, Chicago Committee of 100, 1957; Brotherhood Award, Chicago Conference on Brotherhood, 1957; honorary Ph.d’s from Virginia State College, Tuskegee Institute, and Howard University.

chemistry in 1916. He then went on to complete graduate work in chemistry at the University of Chicago.

Following a series of painful rejections from organizations unwilling to hire a Negro chemist, Hall secured a job with the Chicago Department of Health Laboratories. Within a year he had risen to the position of senior chemist. In 1919, after completing wartime service as assistant chief inspector of powder and high explosives for the Ordinance Department of the U.S. Army, he was offered the job of chief chemist at John Morrell & Company, an Iowa-based meat-packing concern. He remained there until 1921, when he accepted a position with the Boyer Chemical Laboratory in Chicago. “At a time when few blacks were in chemistry, and even fewer in industrial chemistry, young Lloyd Hall began opening doors,” recalled Samuel P. Massie in a tribute to Hall published in Chemistry. The following year Hall became president and chemical director of the Chemical Products Corporation, a Chicago-based consulting laboratory.

Developed Revolutionary Crystals

By the early 1920s, Hall’s interests had turned to the new and relatively unexplored field of food chemistry. At that time, many of his client companies were struggling to find better and more cost-effective ways of curing and preserving their products. The effort to make food “more nutritious and appetizing … for longer life,” as he described his work in an article published in Food Technology, seemed a challenging and worthy undertaking. In 1924 one of his major clients, Griffith Laboratories, Inc., provided him with his own on-site laboratory in which to complete his work. A year later he was appointed chief chemist and director of research for the company.

During his early years at Griffith Laboratories, Hall devoted much of his energy to the search for new and more satisfactory meat-curing compounds. Sodium chloride, or common table salt, combined with nitrogen-containing chemicals, such as sodium or potassium nitrate, had long been used to preserve and enhance the appearance of meat. Chemists had already discovered that nitrate alone was a highly effective color enhancer.

When Hall combined sodium chloride, sodium nitrate, and sodium nitrite in an effort to create a superior meat-curing product, he encountered one major—and seemingly insurmountable—obstacle. The nitrate and nitrite worked much faster than the sodium chloride, causing the meat to disintegrate before it was properly preserved. He had to find a way to delay the curing action of the nitrate and nitrite until the sodium chloride had a chance to penetrate and preserve the meat. Within a short time, he came up with the revolutionary idea of enclosing trace amounts of nitrate and nitrite inside crystals of sodium chloride, so that the sodium chloride could dissolve first, thus preserving the meat before the nitrogen-containing salts were released.

Hall was able to accomplish this by producing a strong solution of sodium chloride, adding small amounts of nitrate and nitrite, and then “flash drying” the solution by evaporating it over heated metal rollers. Once patented, his flash-dried crystals became the most widely used and most effective meat-curing product on the market. He later developed a highly successful anti-caking compound composed of glycerine and alkali metal tartrate, which, when added to the sodium chloride and nitrate solution before flash drying, produced more powdery, freer-flowing crystals. The compound also prevented the salts from absorbing excess moisture when stored in drums and other containers.

Sterilized Spices

Hall also turned his creative genius to the problem of microbial contamination in foods and food products. Although it was widely believed that spices helped to preserve foods, he discovered that many of the most commonly used seasonings, such as cloves, ginger, and garlic powder, harbored large numbers of dangerous molds, yeasts, and bacteria. Thus, meat packers and other manufacturers who added spices to their products were actually contaminating them. In the search for an effective means of sterilizing seasonings, Hall tried heating them in the air, exposing them to evaporation and oxidation, and baking them in hot ovens. Every method he used either destroyed the flavor and aroma of the spices or changed their natural color, making them unmarketable. Chemical sterilization proved equally unsuccessful—until he stumbled upon ethylene oxide gas, a well-known insecticide.

Once Hall had determined that ethylene oxide was as effective in destroying food-borne microbes as it was in killing insects, he had to come up with a way of removing moisture and gases from the surface and interior of the foodstuff so that the germ-killing effect could take place. His solution was to subject the foodstuff to a vacuum, and then introduce ethylene oxide gas into the vacuum chamber so that the material could be sterilized. The temperature of the gas and the length of exposure varied according to the microbes present. It was his discovery of the “Vacugas” sterilization treatment, later applied to drugs, hospital supplies, and cosmetic materials, that, according to a tribute published in Griffith Laboratories’s anniversary retrospective, The First 75 Years, “may really have cemented Lloyd Hall’s hold on the title ‘Griffith technology genius.’”

Pioneered Antioxidant Usage

Following his triumphant success with Vacugas, Hall focused his attention on another major problem in the field of food chemistry: that of rancidity in fats and oils. Foods containing fats or oils become “rancid,” or spoiled, when certain ingredients in the fats or oils react with oxygen in the air. This oxidation produces an undesirable odor and taste, making the product unfit for human consumption. In the course of his experimentation with antioxidants—chemicals that retard or prevent oxidation—Hall discovered that tocopherols, or compounds with antioxidant properties, were found only in crude, or unrefined, vegetable oils. He pointed out that products containing refined oils became rancid more quickly than those containing unrefined oils. Hall became the first to use the chemicals lecithin, propyl gallate, and ascorbyl palmitate as antioxidants, and later developed processes that made it easy to mix these chemicals with the foods to be protected.

Among Hall’s most successful and most widely used products was an antioxidant salt mixture made up of propyl gallate, citric acid, propylene glycol, and sodium chloride. Hall also gained wide recognition for his work with hydrogen hydrolysates, or flavoring materials derived from the hydrolysis, or breaking down, of a variety of proteins. His pioneering efforts in this area convinced Griffith Laboratories to open a large manufacturing facility devoted to protein hydrolysates. Hall later became interested in the development of yeast foods, detergents, and vitamins, and in 1951, he and an associate won a patent for a process that not only reduced the curing time for bacon from two weeks to several hours, but also improved the product’s appearance and stability.

Served on Professional Boards

In addition to receiving more than 100 patents for products and processes used in the food industry, over the years Lloyd A. Hall produced some 50 scientific papers. He also served on the boards of numerous professional, government, and civic organizations, including the Illinois State Food Commission; the Institute of Food Technologists he had cofounded; the Food Technology Council of the Illinois Institute of Technology; the Science Advisory Board on Food Research; the Chicago chapter of the NAACP, and the Chicago Urban League.

In 1955, Hall was elected councilor-at-large and member of the board of directors of the American Institute of Chemists, becoming the first black person in the Institute’s 32-year history to hold such a position. The following year he was awarded the Honor Scroll of the Institute’s Chicago chapter in recognition, according to Louis Haber in Black Pioneers of Science and Invention, of his “intense interest and influence in promoting professional attitudes and constructive actions in the profession of chemistry, and for his numerous achievements in the field of food chemistry.”

Following his retirement from Griffith Laboratories in 1959, Hall spent six months in Indonesia as a consultant to the Food and Agricultural Organization of the United Nations. In 1962, he was appointed by President John F. Kennedy to serve as a member of the American Food for Peace Council. He spent the last 12 years of his life in Southern California, where he was active in both scientific and civic affairs. Among the many community organizations to which he devoted his time and energy were the American Red Cross, Pasadena Beautiful, and a project called SEED, developed to train underprivileged people for jobs in the chemical industry. Hall, wrote Chemistry’s Massie, “was forever blazing new pathways. Usually, whenever someone said, ‘Let’s wait,’ Lloyd’s reply and action was, The time has come.’”