Despite little formal education, he was ambitious, intelligent, and hard working. In 1901, he was assigned to the New York office of a German dye and chemical manufacturer, and after five years there he returned to Germany to work with a chemist, Dr. Otto Rohm, who had developed a new process for the tanning of leather.

In 1907 the two formalized their partnership and in 1909, as their company grew, Mr. Haas returned to the United States to establish a branch of the enterprise in Philadelphia, a center of the tanning industry. The venture was a success and he soon opened a second branch in Chicago.

In 1913, while on the ship to Buenos Aires to introduce the company's innovation in South America, Mr. Haas met Dr. Phoebe Waterman, an astronomer on her way to an assignment at an observatory in Argentina, whom he married the next year. Born on the North Dakota frontier, she was the daughter of a West Point graduate who was commissioned in the U.S. Cavalry. She had earned an M.A. in mathematics and astronomy at Vassar and was among the first two women to earn a Ph.D. in astronomy at the Berkeley/Lick Observatory of the University of California.

The Rohm and Haas Company prospered under the leadership of Otto Haas, who remained at the helm for fifty years. It expanded its line of products (including Plexiglas and other acrylic polymers) and sold them throughout the world. Mr. Haas's financial policies and his concern for his employees enabled the company to remain strong through the Depression without reducing its workforce. After his death in 1960, Otto and Phoebe's sons, F. Otto and John C., succeeded their father as president/CEO and executive vice president of the company and later as board directors until their retirements.

Today, some third generation family members retain ties with the company.