In 1927, Thimerosal was synthesized and patented by chemist Morris Kharasch at the University of Maryland. Thimerosal is an organomercury compound, meaning that it contains mercury bound to an organic (carbon-containing) molecule. It is a well-established antiseptic and antifungal agent.

Kharasch came to the US from the Ukraine when he was 13, aided by an older brother who had preceded him. He graduated from Crane High School in Chicago (1913), and received his BS at the University of Chicago (1917), and his PhD (1919).

After receiving his doctorate, he held a National Research Council Fellowship at the University of Chicago until 1922, when he accepted an assistant professorship at the University of Maryland. In 1936, Kharasch founded the Journal of Organic Chemistry.