PRODUCT NAME:THIOMERSAL
CAS NO:54-64-8
FORMULA:C9H9
DENSITY:2.508 g/cm3
APPEARNCE:White or slightly yellow powder
MELTING POINT:232 to 233 °C
INFORMATION OF THIOMERSAL:Thiomersal (INN), commonly known in the U.S. 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 apreservative in vaccines, immunoglobulin preparations, skin test antigens, antivenins, ophthalmic and nasal products, and tattooinks.[3] Its use as a vaccine preservative was controversial, and it was phased out from routine childhood vaccines in the European Union, and a few other countries in response to popular fears.[4] The current scientific consensus is that no convincing scientific evidence supports these fears
USES OF THIOMERSAL:Thiomersal's main use is as an antiseptic and antifungal agent. In multidose injectable drug delivery systems, it prevents serious adverse effects such as the Staphylococcus infection that, in one 1928 incident, killed 12 of 21 children vaccinated with a diphtheriavaccine that lacked a preservative.[13] Unlike other vaccine preservatives used at the time, thiomersal does not reduce the potency of the vaccines that it protects.[12] Bacteriostatics such as thiomersal are not needed in single-dose injectables.[14]
In the United States, countries in the European Union and a few other affluent countries, thiomersal is no longer used as a preservative in routine childhood vaccination schedules.[4] In the U.S., the only exceptions among vaccines routinely recommended for children are some formulations of the inactivated influenza vaccine for children older than two years.[15] Several vaccines that are not routinely recommended for young children do contain thiomersal, including DT (diphtheria and tetanus), Td (tetanus and diphtheria), and TT (tetanus toxoid); other vaccines may contain a trace of thiomersal from steps in manufacture.[13] Also, four rarely used treatments for pit viper, coral snake, and black widow venom still contain thiomersal.[16] Outside North America and Europe, many vaccines contain thiomersal; the World Health Organization has concluded that there is no evidence of toxicity from thiomersal in vaccines and no reason on safety grounds to change to more expensive single-dose administration.[17] The United Nations Environment Program backed away from an earlier proposal of adding thiomersal in vaccines to the list of banned compounds in a treaty aimed at reducing exposure to mercury worldwide.[18] Citing medical and scientific consensus that thiomersal in vaccines posed no safety issues, but that eliminating the preservative in multi-dose vaccines, primarily used in developing countries, will lead to high cost and a requirement for refrigeration which the developing countries can ill afford, the UN’s final decision is to exclude thiomersal from the treaty.