So, I was reading today, and sometime later (probably around an hour ago), I got to thinking of the wonderful expression, “Books have an infinite battery life.” And the following thought came to me whilst I was drifting a bit off to sleep: What exactly is the “battery life” of a book?

If you’re anything like me, this sort of open-ended, xkcd-ish question is the kind that gets my brain fired up & my blood pumping.

The Slow Burn

I remember watching that great classic of science fiction, The Time Machine (1960),1 where The Time Traveller reacts in a state of shock whilst picking up a book from the communal “library” & seeing it crumble from a mere closing of its cover. If our book here doesn’t succumb to some other event of damage or destruction first, and assuming it’s stored in ideal conditions, this is (roughly) what will happen eventually.

Over time, its glucose molecules will be less & less capable of keeping themselves together, and it will naturally degrade, bit by bit, on its own. Dubbed “slow fires” by Terry Sanders in his 1987 documentary, Slow Fires: On the Preservation of the Human Record,1 the “Brittle Book Problem”,2 as it’s often called, is a huge issue affecting most paper in the world today, and it mainly affects paper that is neither acid-free nor alkaline in its pH content.

According to the US Library of Congress’s Preservation Directorate, this can be an issue even for professional archival efforts:

Research by the Library of Congress has demonstrated that cellulose itself generates acids as it ages, including formic, acetic, lactic, and ocalic acids. Measurable quantities of these acids were observed to form under ambient conditions within weeks of the paper’s manufacture. Moreover, paper does not readily release these acids due to strong intermolecular bonding. This explains why pH neutral papers become increasingly acidic as they age.

Because we’re talking about a material object, the exact lifespan of any given book is impossible to determine here given the sheer number of things upon which it would depend. You’d have to know a lot of details specific to that item, such as:

  • How much paper is it comprised of? What are its dimensions?
  • What type of paper was used: Papyrus? Parchment? Cotton rag? Wood pulp?
  • What chemical treatment did it go through during manufacture?
  • What was its pH level post-manufacture: basic or alkaline (pH > 7), acidic (pH < 7), or neutral (pH ≈ 7, commonly termed “acid-free”)?
  • Was it given an alkaline reserve, such as calcium carbonate (CaCO) or magnesium carbonate (MgCO) to act as a buffering agent against migrating acids from adjacent materials?

I think you get the picture: an approximation will have to suffice.

A Shortage of Information

Unfortunately, there’s not much reliable data on book quantities worldwide: this is due to most major publishers’ great secrecy with in-house sales data, and the few sources that do provide comprehensive metrics are often very costly, subscription-based programmes.

However, a ballpark estimate of at least the US population can still be made here:

According to the Pew Research Center, about 69% of Americans read at least one print book in 2013. Since this included all books read, not just books purchased, I think it’s safe to say that about 69% of all books published in 2013 can be considered the maximum number of books read in 2013. However, Statista data places unit sales for that year at around 2.5–2.7 billion books,3 much higher than the number of books likely read by those Americans represented in the Pew survey.

Therefore, I would think a reasonably fair presumption would be that most Americans who read read mainly books produced in the last 26 years (since 1990).

And, according to this 1989 article by The New York Times, about 25% of all paper produced then was acid-free; this was projected to double within the following year. It’s 2016 now, so if this projection has held true, then a large majority of books produced nowadays are likely acid-free or at least alkaline.

Estimated life expectancies for papers of various pH grades are about 50–100 years for acidic paper and 300–1000 years for alkaline & acid-free paper (see page 4), depending on quality.


  • Pre-1990(-ish) Books: Anywhere from months to 100 years, depending on age, quality, chemical treatment, storage conditions, composition, binding, size & quantity, and so on.
  • Post-1990(-ish) Books: 300–1000 years, depending on quality, chemical treatment, storage conditions, composition, binding, size & quantity, and so on.


1 Courtesy of IMDb.

2 Courtesy of the Northeast Document Conservation Center (NEDCC).

3 Because Statista imposes a paywall for much more than just a snippet of data, I had to do a bit of interpolation: the lede in this source states that unit sales in 2010 was 2.53 billion books, whilst this source reports unit sales in 2015 as 2.71 billion books. So I estimated the 2013 quantity to be around those two numbers. It was a rough estimate, but it got the job done, I feel.


Image Credit: “book”, by Noah Dibley.
Released under a CC BY 2.0 license.
Image has not been modified.
This use does not imply endorsement of the above content by the image’s owner.


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