Which variety of mercury is found in medicine (topical antiseptics → burns)?

• A. Methylmercury
• B. Ethylmercury
• C. Inorganic mercury
• D. Metallic mercury

Answer: (B)

Mercury in medicine comes in several forms, and their uses differ a lot because of how each form behaves in the body. The form that has been used in topical antiseptics (including products used on burns) is an organomercury compound known as ethylmercury. These compounds, often encountered as thimerosal or merthiolate derivatives, combine mercury with an organic group to give antiseptic and preservative properties suitable for skin applications.

Ethylmercury is absorbed and distributed differently from methylmercury, and it is cleared from the body more quickly, which historically made it a practical choice for topical antiseptics and vaccines as a preservative. In contrast, methylmercury is primarily a dietary/environmental toxin with a strong tendency to accumulate in the body and cause neurotoxicity, so it is not used as a medicinal antiseptic. Inorganic mercury salts and metallic mercury are toxic and are not selected for this medical use in topical burn care.

So, the mercury variety found in these topical antiseptic preparations is ethylmercury.