ACS National Historic Chemical Landmark

CLEVELAND, OHIO — The psychedelic, swirling colors emblematic of the 1960s fluoresce with intensity previously unknown to printing inks, pigments, and paints. On Sept. 8, the American Chemical Society (ACS) designated the development of DayGlo fluorescent pigments as a National Historic Chemical Landmark in a ceremony at the Great Lakes Science Center in Cleveland, Ohio.

“Fluorescent pigments are a universally recognizable and truly iconic scientific development,” said William F. Carroll, Ph.D., Chair, ACS Board of Directors. “Beyond being ubiquitous in our everyday lives, from construction cones to clothing, fluorescent colors are a symbol of safety and protection that improve our daily lives. Today, construction workers, firefighters, crossing guards and countless others are safer and more visible because they wear brilliant, fluorescing colors.”

On behalf of ACS, Carroll presented a plaque honoring the development of DayGlo fluorescent pigments to Steve Jackson, President of Day-Glo Color Corp.

Mr. Jackson, speaking of the award said, “We are honored to be included in the National Historic Chemical Landmarks program. The honor is an admirable tribute to the spirit of American innovation and entrepreneurship exhibited by the scientists and visionaries that created our company. The history of fluorescent pigments is a wonderful tale of discovery and development, and a prime example of how the disciplines of chemistry and engineering can be applied to create an entirely new class of material.”

Starting in the 1930s, the Switzer brothers translated their technical know-how into the creation of new pigments that were brighter than anything previously known. Daylight fluorescent pigments—the kind developed by chemists at Day-Glo Color Corp.—convert energy from outside the visible light spectrum (including ultraviolet light) into longer wavelengths that are visible to the human eye. This creates the visual effect of super brilliance, and is comparatively brighter than standard colors. These products became known as DayGlo fluorescents.

The onset of World War II led to new uses of fluorescent technology. Fluorescent fabric panels were used by troops in North Africa to identify themselves as friendly to Allied aircraft, and fluorescing materials allowed Allied forces to use aircraft carriers at night, an advantage over the Japanese military.

Growth in the use of fluorescent pigments for marketing and packaging took off following the War, and by the 1960s, fluorescent colors had become ubiquitous with the emergence of psychedelic posters, clothing, toys, and accessories. Safety products, too, became a major market for fluorescent colors. Today, firefighters, construction workers, crossing guards, and many others are identified by the fluorescent colors emblazoned on their uniforms.

ACS established the National Historic Chemical Landmarks program in 1992 to recognize seminal events in the history of chemistry and to increase awareness of the contributions of chemistry to the well-being of society. Other events recognized through this program have included the world’s first synthetic plastic, the discovery of penicillin, the development of Tide® laundry detergent, and the work of notable chemists such as Joseph Priestley and George Washington Carver. For more information about the program, visit

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 164,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.