Thiomersal
Encyclopedia : T : TH : THI : Thiomersal
| Thiomersal | |
|---|---|
 
| |
| General | |
| Systematic name | Ethyl(2-mercaptobenzoato-(2-)-O,S) mercurate(1-) sodium |
| Trivial names | Elcide Mercurothiolate Merfamin Merthiolade Merthiolate Mertorgan Merzonin Merzonin sodium Sodium ethylmercuric thiosalicylate Sodium merthiolate Thimerosal Thimerosalate Thiomersalate Vitaseptol |
| Molecular formula | C9H9HgNaO2S |
| Molar mass | 404.81 g/mol |
| Appearance | White or slightly yellow powder |
| CAS number | [54-64-8] |
| EC-No | [200-210-4] |
| Properties | |
| Density and phase | 500 kg/m3 |
| Solubility in water | 1000 g/l (20°C) |
| Melting point | 232 - 233 °C (decomposition) |
| Boiling point | --- |
| Basicity (pKb) | --- |
| Acidity (pKa) | --- |
| Thermodynamic data | |
| Std enthalpy of formation ΔfH°gas | --- |
| Standard molar entropy S°gas | --- |
| Hazards | |
| EU classification | --- |
| R-phrases | R26/27/28R33R50/53 |
| S-phrases | S13S28S36S45S60S61 |
| NFPA 704 | --- |
| Supplementary data page | |
| Structure and properties | n, εr, etc. |
| Thermodynamic data | Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Regulatory data | Flash point, RTECS number, etc. |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) [Chemical infoboxInfobox disclaimer and references] | |
- For discussion on alleged health effects of thimerosal in vaccines, see Thimerosal controversy.:For discussion of attacks on ingredients of vaccines, see anti-vaccinationist.
The compound is being phased out for most childhood vaccinations in favor of single-dose vials.
Thimerosal causes susceptible bacteria to autolyze (break down their own cells with self-produced enzymes) via an unknown mechanism. In the body, it is metabolized to ethylmercury (C2H5Hg+) and [thiosalicylate].
Material Safety Data Sheet
See [Full Material Safety Data Sheet]Stability
Stable. May degrade in sunlight. Incompatible with strong acids, strong bases, strong oxidizing agents, iodine, heavy metal salts.Toxicology
Poison. Experimental neoplastigen and teratogen. Harmful by inhalation and ingestion. May cause reproductive damage. May be harmful through skin contact. Typical OEL 0.05 mg/m³.Chemical Hazard Symbol: T+ = Very toxic Criteria: Inhalation, swallowing, or absorption through the skin in very small amounts can cause considerable damage to health, and may sometimes be lethal. In the event of exposure serious evidence of severe, possibly irreversible damage to health by single, repeated, or prolonged absorption. [MSDS Hazard Symbol T+]
Chemical Hazard symbol: N = Dangerous for the environment Criteria: Liberation into aquatic and non-aquatic environments would present or may present immediate or delayed damage for one or more components of the environment. Precaution: Do not allow to enter sewerage systems, soil, or environment. Observe special disposal regulations. [MSDS Hazard Symbol N]
Personal protection
- Safety glasses, adequate ventilation, protective clothing.
- Risk Phrase: R 26/27/28-33-50/53
- Safety Phrase: S 13-28.1-36-45-60-61
- WGK: (Water Hazard Class): 3 - highly polluting substance.
Timeline
- Early-1930s- first added to vaccines as a bactericide [link].
- Mid-1980s- used as a preservative in virtually all whole-cell DPT vaccines, which were routinely administered four times each to children before eighteen months of age, starting at two months.
- Late 1980s- Hib vaccines are recommended for administration to children at eighteen months. They contain thiomersal.
- Early 1990s- In the USA three doses of Hepatititis B vaccine (at that time containing Thiomersal) are recommended for infants under six months of age, beginning on the day of birth; four doses of Hib are recommended within an eighteen month period, beginning at age two.
- Late 1990s- three of the vaccines included in Vaccination schedules for children between six and eighteen months of age contain thiomersal.
- 1999- The American Academy of Pediatrics requests removal of thiomersal from all pediatric vaccines.
- 2002- The USA Centers for Disease Control (CDC) and the USA Food and Drug Administration (FDA) state that: although thiomersal was to be discontinued in some paediatric vaccines, they would not be recalling any unused stocks, as they 'opinioned' that these stock presented no undue risk and that the change was purely cautionary.
- 2006- The World Health Organization, with US funding, is providing thiomersal-containing vaccines for children in developing countries with the same amounts of thiomersal as were given American children at their peak exposure levels. Current vaccination schedules give these in a shorter time period.
External links
See also: Geier, D.A., & Geier, M.R. (2006). Early downward trends in neurodevelopmental disorders following removal of Thimerosal-containing vaccines. Journal of American Physicians and Surgeons, vol. 11, pp. 8-13.
| Vaccination/Vaccine (and Immunization, Inoculation. See also List of vaccine topics and Epidemiology) |
| Development: Models - Timeline - Toxoid - Trial Administration: ACIP - GAVI - VAERS - Vaccination schedule - VSD Specific vaccines: Anthrax - BCG - Cancer - DPT - Flu - HIV - HPV - MMR - Pneumonia - Polio - Smallpox Controversy: A-CHAMP - Anti-vaccinationists - NCVIA - Pox party - Safe Minds - Simpsonwood - Thimerosal controversy - Vaccine injury |
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