|Description:||Workers in a Connecticut hat making plant shrink and shape hat felt into appropriate sizes. The man at center right is working with a metal cone covered with hat felt that is wrapped in burlap and dipped in the hot water kettle in the foreground. The plant was part of the 1937-1938 PHS industrial hygiene and engineering study of mercury exposure and its health effects in the hatmaking industry, which was published as USPHS Public Health Bulletin No. 263, Mercurialism and its Control in the Felt-Hat Industry, 1941. The process is noted in the captions of several photos in the Bulletin”|
“The terms hardening, starting, wetting down, and sizing refer to successive stages in a shrinking process by which the hat body…is reduced to specific size by being wrapped in burlap, dipped in hot water, and kneaded by hand or on rotating rollers. About three-eighths of the employees of felt-hat factories are engaged in [these] operations. The average atmospheric mercury concentration was 2.1 mg. Hg per 10 M3 air.”
The NIOSH Historic Photo Collection began as the “picture file” of the Industrial Hygiene Division of the U.S. Public Health Service (USPHS), c. 1930-1960. It is a unique collection of mid-20th Century images of American workers and workplaces and documents occupational safety and health research of that era. The collection consists of approximately 1,000 original photographs and schematic drawings.