Mercurochrome memories

After I wrote my last blog post on mercury, readers wrote to ask about the old-time antiseptic Mercurochrome which - as you might imagine - was named for the poisonous traces of mercury mixed into it.

One man wondered about childhood toxic exposure. Another noted that her mother still liked to tell the story of when she was a little girl and dumped Mercurochrome "all over her beautiful white bedspread."  I had to laugh (my mother likes to tell the story of how I colored all over her white bedspread). But if you know Mercurochrome, you know that it would have made an incandescently brilliant splash of color on that pale fabric.

This was a thin liquid painted on the skin with memorable effect: a glowing red-orange with just a hint of pink, a deeply hued chemical sunrise.  For a while it was the most popular antiseptic used. Almost every kid I knew growing up in the 1960s had tribal streaks of Mercurochrome over scratches and scrapes. Some used it like warpaint  - creating bright tattoos and lacy designs over faces and chests.

And as a dedicated fan of early 20th century murder mysteries, I still remember a tale by writer Mignon Eberhart in which a killer painted her lips with Mercurochrome rather than lipstick (which turned out to be a vital clue in solving the case). But also, you have to admit, less than a positive image for the antiseptic itself.

Which leads me to a few other facts about the once ubiquitous Mercurochrome. The compound is a mercury derivative of a red dye, hence the bright color. The dye was discovered in 1889. The antiseptic formula that would become Mercurochrome came some 20 years later, developed by researchers working with Baltimore's Johns Hopkins University. Mercury was an extremely popular pharmaceutical ingredient during the 1920s, found in numerous other medications such as calomel and  bichloride of mercury (corrosive sublimate).

So one worried much about a  colorful antiseptic that was only 1 percent mercury by total weight. It wasn't until the 1970s that the U.S. Food and Drug Administration began reevaluating such compounds and became a little uneasy. By that time, mercury's reputation was far less medicinal. It was recognized as a dangerous neurotoxin. Equally important, scientists had learned that mercury bioaccumulates - meaning that each exposure adds up as the material is stored in fatty tissues.

No one really one is certain of the risks that might follow painting Mercurochrome on skin.  People have wondered. Questions about its toxicity were raised as early as 1931 and the occasional poisoning report as been published, usually related to over usage. But in 1998, the FDA decided that reducing mercury exposure just made sense and reclassified the antiseptic as an "untested" drug, meaning that anyone seeking to sell it in the U.S. would need to go through a new approval process.

There were no takers, which means that we'll probably never be quite so colorfully antiseptic again. But there's no reason to feel nostalgic.  Science tells us that if you once were painted with Mercurochrome, your body has probably stored at least a trace of it for you -  nothing apparently too dangerous, just a reminder of your chemical past.