Getting rid of musty odor is usually a losing proposition. Some people will insist that they've gotten rid of musty odor with dryer sheets, carpet freshener, or cat litter. But did they really? Or did they just substitute one odor with another?
Other people swear that wrapping books in newspaper works. Or placing in a container with charcoal. Or using essential oils. Or using baking soda and placing the books in the freezer. Or microwaving the books.
I've tried most of these methods, and they don't work.
Carpet freshener
I used carpet freshener on books that had a strong mothball odor. The books then smelled like mothballs and carpet freshener. Yuck. I couldn't keep the books. This method is a very bad idea.
Baking soda with or without the freezer
This does fade the odor, but it doesn't go away. It also tends to return. This method doesn't work.
Wrapping in newspaper
One time I did get rid of cigarette odor this way and failed another time. I've never tried with musty odor, but if this method failed with cigarettes, then it won't get rid of musty odor.
Microwaving the books
I have microwaved books. This method temporarily reduces the odor, but it comes back. The books can also scorch if you're not careful. Ask me how I know. Don't microwave your books.
I have never tried charcoal or essential oils. Charcoal is too messy, and using essential oils is odor replacement.
There is one more method: using an ozone generator. I purchased an ozone generator in 2021.
Ozone generators are dangerous. If you ever use one, you must be very careful to use it away from pets, animals, and people. Ozone is toxic to the lungs.
This bears repeating:
Ozone is toxic to the lungs.
Now that I've made that statement, I used the ozone generator on some musty books in 2021 with partial success. I don't think I exposed the books for long enough.
On May 25, 2023, I posted this on Facebook:
This poor book smells strongly of varnish. It's an okay odor which is far preferable to a musty or cigarette odor; I'd just like it to be a bit less strong. I can smell the book from four feet away now that I have it propped open with zip ties. This book is an exciting Kay Tracey purchase which is an upgrade to an earlier printing than what I've owned for years. I'd turn the book around and photograph the front, but the zip ties would fall out.
This is the book.
I treated the book with ozone for an indefinite amount of time. I don't know how long, because I don't remember. I got rid of the fragrance, but it was replaced with an ozone odor. I still didn't like it, but it was an improvement. What I thought was varnish was gone.
Sometime later, the seller asked me if I'd "smelled the roses." It turned out that what I perceived as strong varnish was from a rose-scented box that the seller reused to ship the book. She was proud of herself and thought it was great.
If you ever sell books, never use any kind of fragrance in or on the packaging. Buyers like me will hate you. While I wouldn't leave negative feedback over a fragrance, many book buyers would.
The ozone smell was not permanent, which I knew. I shelved the book and hadn't checked it until working on this post. The book now has no odor other than the smell of paper. It smells great! The ozone worked.
Fast forward to November.
I purchased a rather cheap bulk lot of Nancy Drew books, most of which have dust jackets. When I opened the package, I discovered that the books had a very strong musty odor—a very pungent, dreadful musty odor. Imagine the worst musty odor you have ever smelled, and that was how these books smelled.
Many of the books were solid blue and tweed Nancy Drew books from the early 1950s with good quality paper and in dust jacket. These were books that I hoped to sell. The musty odor was so awful that I could not possibly sell the books for much of anything. Despite the hassle involved, I had to get out the ozone generator.
I do this outside away from the house. I have an outbuilding with a porch that has a roof. The building does have electricity and is about 100 feet behind the house. I found a large cardboard box and placed on the porch. I used zip ties to prop the books open. The books and the ozone generator went into the box. Here are pictures.
The ozone generator has a three-hour timer. This is because it's not safe to approach the ozone generator while it's running. It must shut itself off. I kept the ozone generator unplugged while I prepped the books. When I was ready, I turned the dial to three hours and shut the box. I plugged in the ozone generator, then I walked away quickly while holding my breath. I took no chances.
I waited until I felt certain that the time had expired, and then I waited a bit longer, maybe 20 minutes. Ozone has a short half-life and dissipates quickly. When I checked on the books, I made sure that the ozone generator was off. I held my breath, opened the box, and moved away. The wind was blowing on this day, so any ozone left would have disappeared fast.
I then repeated the process, over and over. Each time I cycled the books, I checked one. At first, the books still smelled musty. It was at about 12 hours that I thought the musty odor might have been removed. I wasn't about to go to this much trouble again, so I continued cycling the books. All told, the books were treated to ozone for 21 hours. By that point, the books had a strong ozone odor.
In case you're wondering what ozone smells like, I'd describe it as smelling like the vinyl lining of an above ground swimming pool. Other people say that it smells similar to chlorine. It's a clean smelling odor.
Once I was finished, I got the books in the house and up on shelves to air out the ozone.
I'm not sure how long I left the books on the shelves. At first I thought it was for a day or so, but now I think it was probably for one week. The ozone odor did not decrease, and I needed to speed it up.
I moved the books to the garage. Outside air enters the garage, and any books placed in the garage air out quite well. I have a hygrometer in the garage, and the humidity stays between 45% and 55%. The humidity level is fine for books.
Here are some of the books in the garage.
The other books were scattered between other items on the shelves.
I finally checked on the books at either 2 1/2 weeks or 3 1/2 weeks since they were moved to the garage. I detected a very light ozone odor and removed the books from the garage.
I stacked the books and waited a day. I wanted them to be fully room temperature before I checked again. The books smelled lightly of ozone, light enough that the paper smelled like a new book. It was pleasant.
These are the books.
These books are also from the bulk lot, and they have significant water damage.
The rest of the books are fine with no water damage. Old Clock has a damaged dust jacket. Some of the other jackets have water stains that are visible only from the reverse side. Altogether, this is a nice group of books. They will be sold. I have written "ozone" on a sticky note placed inside each book. The books get mixed in with other books that will be sold, and it's important that I keep track of these. I will disclose that the books were musty and now aren't, just in case some allergens remain.
Conclusion
The horrific musty odor is gone. The remnant ozone odor is pleasant and may fade completely given enough time. Even if the ozone odor remains, most people would just smell paper.
Some people use ozone generators inside their homes when they deodorize books. They seal off a room where they run the ozone generator. I cannot do that since my home has central heat and air. There is no possible way to seal off a room. Air will be pulled into the central unit no matter what. My only solution is to do it outside or in an outbuilding. I prefer outside so that I know that the ozone has dissipated. Ozone is the best way to remove odors from books, but make sure that you know what you are doing before you proceed.
