After studying chemistry, Irmgard Spiess first worked as an assistant at the University of Heidelberg and then in the patent department at BASF. In 1927 she joined her husband's family chemical company. She managed it for decades and still came regularly to the company at the age of 100.

Irmgard Spiess, née Hogrefe, was born on August 31, 1898 in Wesel on the Lower Rhine. At the age of 18, she began studying chemistry at the Ruprecht-Karls University in Heidelberg, where she received her doctorate summa cum laude in 1921. Your doctoral supervisor Emil Knoevenagel (1865-1921) was a student of the well-known chemists Ludwig Gattermann (1860-1920) and Viktor Meyer (1848-1897) and gave his name to the Knoevenagel condensation, which is well known in specialist circles, an important reaction for the formation of carbon-carbon bindings.

Spiess was the first woman to receive an official position as an assistant at the University of Heidelberg. She then worked in the patent department of BASF for almost two years, where she was also entrusted with library tasks. After marrying Paul Spiess, she moved to Kleinkarlbach in the Palatinate. The Spiess family owned a paint and varnish factory there, which Carl Friedrich Spiess, Paul Spiess' grandfather, had founded in 1861 ? at the instigation of Justus von Liebig (1803-1873), to whose niece the company founder was married. In 1925 the factory started producing phytosanitary products, first for viticulture and later for the entire agricultural sector.

After the birth of her two sons, Spiess joined the family business in 1927 and made a Career there like hardly any other woman in the chemical industry. The entrepreneurial couple Spiess continued to develop the company together. When her husband was called up for military service in 1939, Irmgard Spiess managed the company alone through the turmoil of war and the post-war period. After her husband's release from captivity, the couple ran the business together again. When Paul Spiess died in 1963, his wife continued to run the company, supported at times by their sons. She was active in the company for over 70 years, many decades of which as managing director, and she still came regularly to the company at the age of 100. The management of the company is said to have remained in her hands until the end of her life. For her life's work she received the Federal Cross of Merit First Class and the Order of Merit of the State of Rhineland-Palatinate. Irmgard Spiess died on January 28, 1999 at the age of 100 at her home in Kleinkarlbach.

The Career of the chemist Spiess is without question remarkable, but from today's perspective at least one product that her company once traded in is questionable. Crucial to the business success was the licensing in 1943 for the insecticide dichlorodiphenyltrichloroethane, DDT for short, which had been used extensively as a contact and stomach poison since the early 1940s. Because of its toxicity, persistence in the environment, and accumulation in the food chain, the use of DDT was banned in most western industrialized countries in the 1970s. Worldwide, the chemical is now only approved for controlling disease-carrying insects such as the malaria mosquito.