Thiomersal

Thiomersal (INN), and commonly known in the US as thimerosal, is an organomercury compound. This compound is a well established antiseptic and antifungal agent.

The pharmaceutical corporation Eli Lilly and Company gave thiomersal the trade name Merthiolate. It has been used as a preservative in vaccines, immunoglobulin preparations, skin test antigens, antivenins, ophthalmic and nasal products, and tattoo inks. Its use as a vaccine preservative is controversial, and it is being phased out from routine childhood vaccines in the United States, the European Union, and a few other countries.