The Purity Distilling Company was a chemical firm based in Boston, Massachusetts specializing in the production of ethanol through the distillation process. It was a subsidiary of United States Industrial Alcohol Company who purchased the company in 1917.

Great Molasses Flood

In 1919, one of its largest molasses tanks, which was built in 1915, collapsed at 529 Commercial Street. It was a huge tank (50 ft tall, 90 ft diameter, 283 ft around) and held as much as 2,300,000 USgal of molasses. This led to the Boston Molasses Disaster in the North End neighborhood of Boston. Twenty-one people died, and the cleanup took about 6 months to complete, after which the company was sued and forced to pay over $1 million in settlement claims.