Thimerosal - A & C



A&C has GMP manufactured Thimerosal meeting USP and JP requirements. We also manufacture 2% and 10% (W/V) aqueous solutions under full GMP compliance.


Thimerosal (also known as Thiomersal) was discovered by Morris Kharasch, a chemist at the University of Maryland in 1927. It is the sodium salt of an ethylemercaptomercurate with the CAS number 54-64-8 as identifier. This compound is a well-established antiseptic and anti-fungal agent. In terms of potency it has no equal, suffice it to say that for instance Thimerosal is >40 times more effective than phenol against Staphylococcus aureus. This allows it to be used in exceedingly low dose quantities and despite exhaustive scientific scrutiny has proven safe at the effective levels used in vaccines.

Thimerosal and vaccines

 The frequent use of Thimerosal in vaccines is due to the fact that Thimerosal is simply the most effective preservative available for multi-dose vaccine preparation. It is the best preservative available for the manufacture of multi-dose vials that are the most efficient way to protect our world when vaccines need to be administered to large numbers of people in short periods of time, such as in epidemic or pandemic situations.

According to the World Health Organization for instance, the use of Thiomersal containing vaccines to protect the world’s children against diphtheria, tetanus, whooping cough and flu averted an estimated 1.4 million child deaths in 2010 alone.