Thimerosal
Ethyl(2-mercaptobenzoato-S)(sodium) mercury; Sodium ethylmercurithiosalicylate
Organomercury compound; neurotoxic, nephrotoxic, and reproductive toxicant; banned in EU cosmetics under mercury prohibition (Annex II); banned under the Minamata Convention on Mercury; any cosmetic product containing thimerosal is non-compliant in EU, India, Canada, and most regulated markets; US FDA banned in cosmetics under 21 CFR 700.18.
Function & Common Use
Preservative, Antimicrobial
Preservatives
BANNED in cosmetics globally; formerly in mascaras, contact lens solutions, eye drops; still used as vaccine preservative in some countries
Synthetic
Concentration Limits
N/A (banned)
N/A (banned)
Prohibited in cosmetics (21 CFR 700.18 and 700.27); still used in some multi-dose vaccines as preservative; exception for eye makeup removers at 0.0065% (historical)
N/A (banned)
Format restriction: BANNED in EU and most jurisdictions in cosmetics; banned under Minamata Convention on Mercury in cosmetics globally
Baby restriction: Yes
Pregnancy: Yes
IFRA: No
Frequently Asked Questions
Is Thimerosal safe to use in skincare?
Thimerosal has a High concern rating. Organomercury compound; neurotoxic, nephrotoxic, and reproductive toxicant; banned in EU cosmetics under mercury prohibition (Annex II); banned under the Minamata Convention on Mercury; any cosmetic product containing thimerosal is non-compliant in EU, India, Canada, and most regulated markets; US FDA banned in cosmetics under 21 CFR 700.18.
Is Thimerosal allowed in India?
Thimerosal is currently classified as "Banned" under Indian cosmetics regulations. The maximum permitted concentration is N/A (banned).
What is Thimerosal used for in cosmetics?
Thimerosal functions as: Preservative, Antimicrobial. It is commonly found in: BANNED in cosmetics globally; formerly in mascaras, contact lens solutions, eye drops; still used as vaccine preservative in some countries.
Can Thimerosal cause an allergic reaction?
Yes. Thimerosal has an allergen flag (Yes). If you have sensitive skin or known fragrance/contact allergies, patch-test products containing this ingredient before full use.
Is Thimerosal safe for babies?
Thimerosal has baby/child restrictions: Yes. Avoid using products containing this ingredient on infants unless specifically formulated and labelled for baby use.
Regulatory Status
EU Annex: Annex II (banned) - mercury compound; prohibited in cosmetics
Identifiers
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