One evening a few weeks ago I was about to fill my stainless-steel insulated travel mug with ice and seltzer for the night as I’ve done every night for the last six months. I was wiping off the insides of the thick black lid when I came away with a black smear I’d never seen before. It was from a barely noticeable black slime around the base of the plug that goes into the lid’s opening.
I cleaned it out and searched the internet for “black goo on a thermos” and found many websites for black mold, a type of fungus called Stachybotrys chartum in the mold family. Like every other mold it grows on moist surfaces like the insides of water bottles and insulated hot-and-cold cups.
These molds are not dangerous themselves, according to the U.S. Centers for Disease Control and Prevention, but they can release toxins causing hay fever-like allergic and flu-like symptoms and worse for those with weakened immune systems and lung disease, including chronic obstructive pulmonary disorder and asthma. The allergic reaction to the mold can also cause nausea, vomiting, and bleeding in the lungs and nose. Yikes!
Written by Harlan Levy for the Journal Inquirer