Thimerosal Allergy Facts

This is a compilation of information from True Test, ContactAllergy.com, DermNetnz.com, Center for Disease Control and Protection and U.S. National Library of Medicine. This information may not be complete, check with your doctor if you have further questions..

 

What is Thimerosal?

Thimerosal contains ethylmercury (mercury). Mercury is a naturally occurring element found in the earth’s crust, air, soil, and water. Two types of mercury to which people may be exposed — methylmercury and ethylmercury — are very different. Methylmercury is the type of mercury found in certain kinds of fish. At high exposure levels methylmercury can be toxic to people. Everyone is exposed to some methylmercury. Thimerosal contains ethylmercury, which is cleared from the human body more quickly than methylmercury, and is therefore less likely to cause any harm.

Thimerosal is added to some vials of vaccine that contain more than one dose (multi-dose vials) to prevent growth of germs, like bacteria and fungi. Thimerosal was commonly used as an antiseptic such as Merthiolate or Mercurochrome®. Over the past few decades, thimerosal has been replaced with other preservatives. Now, thimerosal is rarely included in antiseptics or medications, including merthiolate.

A contact allergy to thimerosal should not affect your ability to be vaccinated because most modern vaccines do not contain thimerosal. Vaccines given to children under the age of 6 are made without thimerosal. A few adult vaccines are still manufactured with thimerosal as a preservative, but thimerosal-free alternatives can usually be found if needed.

How To Avoid Thimerosal
  • Be aware that if your spouse or significant other uses topical skincare products that contain this chemical, composite transfer may occur to you.

  • Be aware that if your spouse or significant other uses topical skincare products that contain this chemical, composite transfer may occur to you.

  • Use only products that do not list thimerosal or related chemicals on the label, ingredient list or Material Safety Data Sheet (MSDS). If no information is available, contact the product manufacturer.Tell your physician, pharmacist, dentist, veterinarian, beautician and hairdresser that you are allergic to thimerosal.

  • If you think that you contact thimerosal at work, ask your employer for MSDS or manufacturer information on the product(s). Talk to your employer about using a different product or about wearing protective gloves and clothing to reduce skin contact.

Other names for Thimerosal to Look For and Avoid

To reduce reactions from thimerosal mix avoid products with the following names in the list of ingredients:

  • Materials Safety Data Sheet (MSDS), or package insert
  • Mercurothiolate
  • Mercury, ethy(2-mercaptobenzoato-s)-, sodium salt
  • Mercury, ((o-carboxyphenyl)thio)ethyl-, sodium salt
  • Merthiolate
  • Sodium ethylmercurithiosalicylate
  • Sodium2-(ethylmercurithio)benzoate
What products contain Thimerosal or one of its components?*

Antiseptics
Antioxins
Anti-Fungals
Ear medications (prescription and over-the-counter)
Eye medications (prescription and over-the-counter)
Fluorescent dyes in metal working industries and forensic laboratories
Mercurochrome
Nose medications (prescription and over-the-counter)
Pharmaceutical manufacturing
Soap-free cleansers
Tattoo Ink
Vaccines

* This list may not be all-inclusive. Read product labels carefully and talk to your doctor if you have any questions. Product formulations may change from time to time without notice. Talk to your doctor for specific instructions. For additional information about products that might contain Thimerosal or a related substance, go to the Household Products Database online (householdproducts.nlm.nih.gov) at the United States National Library of Medicine.

Products That May NOT Contain Thimerosal?*

Most vaccines recommended for children under 6 years of age: measles, mumps, rubella (German measles), polio, pertussis (whooping cough), diphtheria, tetanus, Haemophilus influenzae type b (Hib), hepatitis B, varicella (chickenpox) and pneumococcal disease.

* This list may not be all-inclusive. Read product labels carefully and talk to your doctor if you have any questions. Product formulations may change from time to time without notice. Talk to your doctor for specific instructions. For additional information about products that might contain paraben mix or a related substance, go to the Household Products Database online (householdproducts.nlm.nih.gov) at the United States National Library of Medicine

Nancy’s Personal Experience

This chemical has affected me the least to this point. However, I find myself second guessing the use of medical ointments, anxious about my next doctor or dentist appointment. That fact that Thimerosal is in many antiseptics is a concern. My occasional bought with athletes foot may be a new challenge – I will have to see if Thimerosal is in the anti-fungals I use. If it is, then what? Each day there are more questions.

Contact Me

Got suggestions for something that should go on this site?
For allergy emergencies call 911 or visit your nearest hospital.