Air Filtration In Book and Paper Conservation

That “Old Book” Scent Isn’t as Nice as You Thought

For many of us, walking into a bookstore or library instantly comforts us. Not only because we are surrounded by stories and information that excite our imaginations and invoke our interest, but because of… that smell. The chemistry of timeworn books gives them that familiar and to many – soothing – odor. But what is it?

As any book or document conservator can tell you, that “old book” fragrance occurs from the degradation of paper. Though no two tomes smell alike, the combination of chemical decay mingled with the substances used to construct the book – along with where it has been and how it is stored – have often been compared to wood, chocolate, and vanilla, as well as coffee, leaves, and linen. Of course, the odors emitted by books aren’t always pleasant (think: moldy, musty, rancid), and often, they aren’t safe. This is something that many workers in the field of book and paper conservation know only too well. Working day after day with chemical emissions coming out of ancient pages can actually make someone sick.

People who work with old, important, or financially valuable paper-based objects – like books, prints, newspapers, and other documents – are conservators or conservationists. Under this umbrella term are three different and distinct disciplines.

Preservation aims to protect paper artifacts from additional damage without altering the item.

Restoration is the goal of returning an object to its original condition.

Conservation – protecting a specific item – uses chemistry to stabilize a book or document’s condition with the intent of extending its lifespan in addition to maintaining its integrity by keeping all changes reversible.

The Importance of Understanding the Chemical Composition of Aging Books and Documents

As a book or document ages, the elements used to create it begin to break down. Substances such as paper, ink, and adhesive will release VOCs (volatile organic compounds), creating a distinctive aroma. For example, lignin is an organic polymer found in many plants and is present in all paper made from wood. It is closely related to vanillin, the fragrant compound in vanilla. Other pleasant-smelling ingredients, such as acetic acid (smells like vinegar) and benzaldehyde (has the odor of almonds), both exist in inks. But not all paper artifacts give off a pleasant scent as they age. Books with water damage may smell mildewy and cause itchy eyes and a stuffy nose.

The fumes don’t just come from the books themselves. The restoration and preservation processes require their own chemicals. Many solvents used for parchment washing, adhesives to repair torn pages, and pigments to restore color can emit toxic vapors.

But the smell alone isn’t the real problem. The stink is simply nature’s way of sounding an alarm that something not-so-good is happening.

The Health Risks Associated with Occupational Exposure to Paper-Related Contaminants

There are health risks from occupational exposure to paper-related contaminants. When a book, newspaper, or manuscript deteriorates, the off-gassing of fumes causes toxins to enter the surrounding area – the literal breathing space of a conservationist. And just because something smells mildly pleasant, like that “old book smell,” doesn’t mean it’s safe.

The vapors of many chemicals can be toxic either when in an enclosed area or when exposure lasts for an extensive duration (such as a typical workday). Consider this short list of common substances either released from old books or emitted during the process of conserving them. The symptoms noted are only a fraction of the potential health risks.

Toluene – commonly found in many cleaning solvents, can cause headaches, confusion, and nerve damage.

Mercuric Chloride – this highly toxic insecticide was used commonly in the early 20^th century to preserve wood products, including book covers. Exposure symptoms include abdominal pain, breathing difficulty, and throat pain.

Ethyl Hexanol – is used in various pigments and adhesives and has been reported to cause eye irritation and is harmful if inhaled.

Lead – some printing inks once contained this common metal. Dust from these texts can result in lead poisoning. Symptoms include but are not limited to, abdominal pain, headaches, fatigue, and nervous system dysfunction.

Protecting Indoor Air Quality for Book and Paper Conservation Through Air Filtration

Worker safeguards exist. Modern book and newspaper printers have limited the types of toxic substances used in their production. Furthermore, government entities and private businesses have gone to great lengths to protect people from health risks associated with book and paper conservation. Unfortunately, that doesn’t help a curator of ancient texts who has been tasked with preservation. So, what’s the best approach to keeping indoor air quality (IAQ) clean and risk-free? Air filtration.

Luckily for book conservators, there are tools to combat dirty air in the form of pollution removal products such as our bench-top BT981-3 and mobile SP987-3 source capture systems, both of which provide the ultimate combination of consistent airflow with superior filtration, all in a compact design.

At AIRSInc, our products go a long way in keeping our customers in the book and paper conservancy industry – as well as the collections they have been hired to protect – safe. Contact us today for no-cost clean air analysis.