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Removing Odors From Books With An Ozone Generator

A Bookseller's Guide

by Craig Stark

#117, 24 March 2008

Books are like sponges. They soak up odor by the gallon, and the most offensive of these odors will all but destroy values. There are dozens of techniques for eliminating book odor - BookThink itself has published an article that recommends using baking soda - but most of them involve the use of chemicals and lots and lots of patience, sometimes weeks of it. And even then odors may return over time. A few chemicals (or other odor eliminating products like charcoal) are safe to use, others questionable; and still others will inevitably damage the books they are intended to restore. Or make them smell like lilies!

I'm going to propose a faster and more effective method, one that not only eliminates odors quickly and completely but also treats mold and mildew - ozone.

Ozone, a gas consisting of three oxygen atoms, is an allotrope of oxygen - that is, it's comprised of exactly the same element but differs in the bonding arrangement and/or number of atoms, in this case possessing three atoms instead of two (as in oxygen). The good news here is that ozone is much more unstable than oxygen and, given normal atmospheric conditions, will tend to slough off the third atom, whereupon the orphaned atom will oxidize or attach itself to the first receptive thing it bumps into - a very good thing indeed if the host is an active mold spore because oxidation will certainly destroy it.

Devices that manufacture ozone - specifically, ozone generators - have proven highly effective at eliminating odors produced by smoke, mold, mildew and so on, in some cases destroying the very things that are causing them. Additionally, if books are infested with any creeping organisms, they will be zapped as well.

The process for booksellers couldn't be simpler, but it's important to acquire a generator that matches your application and come up with a relatively air-tight enclosure to house it and your books. Also, there are a few tricks that will facilitate things, not to mention some stuff to watch out for.

First, the generator. It needs to be powerful enough to get the job done but not so powerful as to be prohibitively expensive or dangerous. For our purposes, a 12-watt unit will be more than effective and not break your budget. Don't waste your money on less powerful units that promise the moon, and especially vendors who conveniently forget to specify wattage. A 12-watt generator is designed for use in small areas (like refrigerators) - or the somewhat smaller enclosure I'll recommend for your books. Here's what I use.

If the price gives you pause, used units come up often on eBay and can sometimes be acquired for under $100. Also note that bulb life is approximately 9,000 hours - enough to treat thousands of books.

Second, an enclosure. This is one occasion when a cardboard box won't do because the idea is to keep the ozone confined so as to be both available to do its thing and to stay the heck out of your lungs. Small amounts of ozone pose little or no threat to your health; larger amounts, however, may damage your lungs. My rule of thumb is, if I can smell it, it's too much. My enclosure is a Styrofoam cooler that once transported some overpriced steaks:

It's deep enough to accommodate tall books stood vertically (more about this later), and the lid fits snugly enough to keep the ozone in. I punched a hole big enough to feed the plug into it on the side, then plugged it with some plumber's putty.

You could also use a plastic bin with a snap-on lid, but I'd be less comfortable with this nearby unless the lid could be modified, perhaps with adhesive foam insulation, to fit more tightly.

Books pose a special problem for odor treatment because they are at once porous enough to absorb odors into every last page but not quick to give them up, given that the pages are in such close contact to each other. Standing books up in the generator housing with pages fanned open is essential, of course, but it's impossible to fan all of them or even most of them open. Here's what I do to make sure everything gets zapped quickly:

Cable ties can be inserted between pages in a matter of minutes, sometimes moments, and are thick enough to keep the pages separated but not so thick as to be unworkable. They can be purchased in bulk in numerous sizes at any home improvement center and will last indefinitely. I use 14" ties on everything, even books taller than 14".

So - how fast can a book be treated? If it's simply an odor issue, sometimes in a matter of hours, sometimes overnight or in a day or two. A lot depends on the porosity of the paper and how many pages are involved. A few books will require longer treatments, especially if mold or mildew is present. Generally, you can safely acquire a problem book, list it immediately, and have it ready to ship in an odor-free state should it sell quickly.

A few small cautions. There are, apparently, a few fabrics and papers that can be adversely affected by ozone, also some dyes used to color them. The risk seems small overall - I've yet to have an issue - but it's there nonetheless.

Finally, a GIANT caution. If you're going to zap books with mildew, yes, it can be entirely eliminated, theoretically, but if you don't get it all - and how will you know if you do? - where are you? At an ethical crossroad. A small number of remaining active spores (which would be difficult to detect by smelling) could eventually propagate into a big problem. If the book travels to another library, it could spread the problem to other books. It's one thing if you're risking a book you plan to keep, quite another if you're selling it.

Questions or comments?
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