Is Mercury Still Used in the Making of Men's Dress Hats?  -Warren, Boise ID

Great Question, Warren!  I'm going to do the best I can to answer this one, because it's an excellent question, but if some other hat expert has anything to add, please comment and I'll gladly update and edit this post.

In some places in the world, Mercury, in small amounts, may still used in the felting process of men's hats.  Most places, however, have found an acceptable alternative in Hydrogen Peroxide.  For hundreds of years, hatters had used mercuric nitrate on rabbit and beaver felt hats to separate the furs from the pelts in a process called "carroting."  In the old days, ventilation was often poor and the effects of inhaled mercury were not well understood, and many of the men who were felting the hats would inhale enough mercury to cause ill effects, hence the "mad hatter" syndrome.

Due to the Alice in Wonderland character, this is often thought of as a problem overseas, but mercuric nitrate was used in the US and all around the world in the felt hat manufacturing process, including right here at Levine Hat Company when we made our own felts all the way into the 1940s.  By the early 1900s, when we were felting a lot of bodies, we already understood the dangers of mercury and achieved much of our carroting with less mercury and more boiling, not to mention we had masks, fans and ventilation due to the heat of our factory anyway.  At some point our factory may have switched to Hydrogen Peroxide, which was slightly less expensive and much less dangerous (if a slightly longer process)

The last recorded cases of "mad hatter" syndrome were in the early 1940s, and it is common knowledge that readily available Hydrogen Peroxide can achieve mostly the same result as the old Mercury, and it is much easier to acquire, so it's hard to understand why anyone would still be using the old mercury method in making felt for men's dress hats!

I hope that answered your question!