MASS DEACIDIFICATION PILOT PROJECT

The pilot project to evaluate the Bookkeeper process for mass
deacidification was carried out in two phases. The first phase was a
survey of the NLM post 1800 collection to determine how many volumes
were suitable for treatment with the Bookkeeper process. The second
phase consisted of deacidification treatment of 184 volumes and an
evaluation of the results.

I.  DEACIDIFICATION PROCESS

The Bookkeeper deacidification process treats materials in small
batches. Bound volumes are fanned open on specially designed racks that
are placed in tanks. The deacidification liquid, magnesium oxide
suspended in perfluoralkane, is pumped into the tank and submerses them
for about 30 minutes. Gentle motions of the paper and liquid are used to
help to ensure uniform coverage. The treating bath is continuously
circulated to filter loose dust and dirt from the books and to monitor
and maintain the proper concentration of treating materials. All unused
perfluoralkane is then evicted from the tank and recovered, making the
process both environmentally friendly and economically efficient. A
vacuum is pulled into the tank to aid the drying process. A batch
usually takes about 2 hours. Because the treatment does not use water or
other solvents, inks, bookcloth, and glues are not damaged in the
process.

Very small particles (about 1 micron) of magnesium oxide are deposited
into the structure of the paper. In the first few weeks following
treatment, the magnesium oxide particles combine with moisture in the
air to form magnesium hydroxide, a non-toxic alkaline reserve. The
particles that make up the alkaline reserve readily absorb and
neutralize the acids in the paper and continue to absorb acid over the
life of the paper. This has been demonstrated by accelerated aging tests
and tests done with books treated over the past eight years. These tests
have shown that treatment by the Bookkeeper process should extend the
usable life of paper based materials 3 to 5 times. The Bookkeeper
process is already being used to deacidify about 200,000 volumes and
3,750 cubic feet of manuscript or archival material per year from 40
research libraries. The Library of Congress recently announced plans to
increase the number of volumes they send for treatment from 100,000 to
300,000 per year.

Not all acidic materials are suitable for treatment by Bookkeeper. The
Bookkeeper process is not as effective with coated paper. The magnesium
hydroxide remains on the coating and does not react with the acids in
the paper. The small chamber size also places size limitations on the
volumes treated though new treatment tanks make it possible to treat
larger volumes and manuscripts in a separate processing stream. Volumes
must be structurally intact to be put on the racks and subjected to the
movement of the fluids in the tanks. The process does not strengthen
already brittle paper. Therefore, filmed, already brittle, and damaged
volumes are also not suitable for treatment.

![](media/image1.png){width="2.8541666666666665in" height="3.75in"}
![](media/image2.png){width="3.095833333333333in"
height="3.526388888888889in"}

Book Rack Deacidification Treatment Tanks

> ![](media/image3.png){width="3.7395833333333335in" height="2.90625in"}

System of Tanks

II\. COLLECTION SURVEY

The survey was necessary to identify what portion of the collection
could be treated and to help set priorities for treatment. A survey of
the collection was designed to gather data needed for making selection
decisions. One thousand volumes were surveyed. Volumes were surveyed
from six subcollections, the same subcollections included in an earlier
study of brittleness done in 1987. These subcollections were: Serials
published 1989 to present, classed W1 (B1), Serials published 1914 to
present, classed other than W1 (B2), Serials published 1871-1989,
classed W1 (B3), Monographs published 1914 to present (B2), Serials
published 1801-1870 (HMD), and Monographs published 1801-1914 (HMD).
Random numbers were generated to select a particular volume from a
particular shelf within each collection area.

During the week of August 21-25, two employees of Bookkeeper pulled and
examined volumes and recorded data for the survey. The following data
were collected about each volume and input into an Access database:

> Bibliographic/Identification: Title, call number, date, country of
> publication, item barcode, collection location
>
> Size: Height, width, thickness, weight
>
> Physical condition: Binding style, acid or alkaline paper as measured
> by a pH testing pen, coated or calendared paper, brittleness as
> measured by foldtest, damage

## Volumes Suitable for Deacidification

  ----------------------- ----------------- ------------ -------------- -------------
  **Collection Location** **Percent of                   **Number of    
                          Subcollection**                Volumes**      

                          **Uncoated**      **Slightly   **Uncoated**   **Slightly
                                            Glossy**                    Glossy**

  **Serials B1            **5.8%**          **5.2%**     **19,490**     **17,470**
  (1990-2001)**                                                         

  **Serials B2 (1914-     **52.0%**         **18.0%**    **50,440**     **17,460**
  2001)**                                                               

  **Serials B3            **21.1%**         **17.3%**    **161,630**    **132,520**
  (1871-1989)**                                                         

  **Serials HMD           **28.6%**         **4.8%**     **11,330**     **1,900**
  (1801-1870)**                                                         

  **Monographs B2         **40.9%**         **14.7%**    **249,490**    **89,670**
  (1914-2001)**                                                         

  **Monographs HMD        **37.3%**         **3.9%**     **37,300**     **3,900**
  (1801-1913)**                                                         

  **Total**                                              **529,680**    **262,920**
  ----------------------- ----------------- ------------ -------------- -------------

Survey results indicate that approximately 529,680 volumes or 27.2% of
the surveyed collection are acidic, not brittle and on uncoated paper.
The treatment of these volumes should be fairly straightforward. The NLM
has much coated paper, but early coated paper is not as thickly coated
and is only slightly glossy. For the survey purposes, coated paper was
categorized as either heavily coated or slightly glossy . There were an
additional 262,920 volumes (13.5% of the collection) that are acidic,
not yet brittle and on slightly glossy paper. We have discussed the
treatment of the slightly glossy paper with Bookkeeper and they are
planning to test new processes so that such volumes can be treated
successfully.

![](media/image4.wmf)\
Survey results show a significant decline in the amount of acid paper
acquired in the collection since the mid 1980's. However, 12.1% of
materials received since 1996 were found to be on acidic paper.

Another relevant finding of the survey was that 12% (233,832 volumes)
were brittle. This represents 65,832 more brittle volumes than were
brittle in 1985. This means that almost 4,500 volumes are becoming
brittle each year. The cost of microfilming is over \$180.00 per volume,
the cost of deacidification is about \$18.00 per volume. The cost of
microfilming the 4,500 volumes that will become brittle in one year is
over \$ 729,000 more than deacidifying them before they become brittle.
The cost of microfilming the 800,000 volumes destined to become brittle
is \$144 million while the cost of deacidifying them before they become
brittle is \$14.4 million.

III\. DEACIDIFICATION RESULTS

The second phase of the Mass Deacidification pilot study was to select
volumes for deacidification and send them to Bookkeeper. The procedures
and specifications were similar to those envisioned for a larger
contract. The purpose of this phase was to test the logistical
procedures for handling and shipping and to determine whether the
Bookkeeper process was effective and non-damaging. The effectiveness of
the treatment was based on the resulting alkaline reserve and the change
in pH before and after treatment.

For the sample we selected acidic volumes in good condition from titles
in the original sample population. We did this because we had already
collected data about their physical characteristics and condition. A
Bookkeeper staff member who selects volumes for deacidification at the
Library of Congress reviewed our selections to make sure they would not
incur damage and packed them for shipment in the Bookkeeper totes. One
hundred and eighty volumes were selected from the sample.

To determine how slightly glossy volumes would respond to treatment, I
took additional volumes that were slightly glossy to the Bookkeeper
facility in October before the deacidification was done to discuss how
they might be handled. We agreed to deacidify four of those to evaluate
their post treatment condition. In all, 184 volumes were deacidified.

The pH of the volumes was measured before and after treatment with a
Fisher Scientific Accumet pH meter. I visited Bookkeeper prior to the
treatment of the volumes to learn how Bookkeeper measured the pH so that
the readings taken at NLM after treatment would be consistent with those
done by Bookkeeper. The volumes sent were determined to be acidic on the
basis of a test with a pH testing pen containing Chlorophenol red
indicator solution. This test can be unreliable on coated or colored
paper. During our pretreatment pH testing using the Accument meter,
nineteen volumes were found to be non acidic (above pH 6.8).[^1] We went
ahead with deacidification, but noted that we may need to evaluate the
readings we get from pH pens for certain paper types. These volumes will
be excluded from this report. The pH readings of the remaining 165
volumes prior to treatment ranged from 2.84 to 6.65 (Average: pH: 4.5).

Besides recording the pH tests, the Bookkeeper staff again examined the
volumes to make sure they could be treated without damage. They
documented instances of minor damage existing prior to treatment.

The volumes were deacidified and returned to NLM in November. In late
January and early February, I did pH testing of all the deacidified
volumes. The tests were not performed immediately after deacidification
because the treatment reaction continues for some time after the deposit
of the alkaline materials in the book. The Library of Congress specifies
that the pH of deacidified books should be between 6.8 and 10.4.[^2] The
pH readings for the NLM sample after treatment ranged from 6.41 to
10.32. The average pH of treated volumes was 9.3. The pH of all volumes
increased at least 1.77. The average increase in pH was 4.9. See
attached table for pH readings before and after the treatment.

There were only 3 volumes where the resulting pH was below 6.8 or showed
less than 2 points increase. Further testing showed that all 3 volumes
had significantly higher (all over 9.2) pH readings on another page
within the book. This is due to variations in the paper within the
volume and uneven distribution of the alkaline particles. It has been
shown that acids migrate toward the areas of the alkaline particles so
that once treated the acids throughout such volumes eventually will
become neutralized.

The alkaline reserve is a measure of the amount of treatment materials
deposited in the paper. Library specifications for minimum alkaline
reserve range from 1.0 to 1.5.[^3]

To test for consistency of treatment among treatment batches, Bookkeeper
placed sheets of neutral Watman paper in volumes so that 5% of the
treating chambers used for the shipment were tested. The test papers
were cut into two equal parts. The Contractor tested one half of the
batch of test papers and reported the results to NLM and returned the
other half of the papers to NLM for independent testing. In the test
papers the alkaline reserve ranged from 1.2-1.7 and the pH ranged from
9.8-10.0. No further testing for alkaline reserve was done, as this test
requires destroying the paper.

I examined the volumes when unpacking and again in more detail when
performing the pH tests. I found no damage caused by the mass
deacidification treatment or the Bookkeeper handling of the volumes. One
or two of the buckram covers felt tacky. This is due to a reaction with
oils used in the production of some pyroxylin coatings of book cloths.
Bookkeeper has a method of wiping off this residue from the cover.

It must be noted that the treated volumes do have a slightly different
feel to the paper. There is a slight residue that leaves a dusty feel to
some types of paper. More of this residue is left on glossy pages but
Bookkeeper wipes these pages and the covers off as a matter of course.
The four slightly glossy volumes were intentionally not wiped, but the
residue did not seem to be more noticeable than that found on other
volumes. While I do not find the feel of the treated books unacceptable,
it is likely to be noticed by some users.

A label was applied to the inside of the back of the volume which
recorded: name and address of the company providing deacidification
services, the name of the deacidification process, identification of the
neutralizing agent employed, and the date of the treatment. Also a small
dot was placed at the bottom of each volume to give a quick visual
reference that the book was treated. In addition to the labeling of the
piece, the Voyager item record will be updated to indicate that the
volume has been deacidified so that we can generate reports and test for
changes in pH in future years.

IV\. RECOMMENDATIONS

Almost 800,000 volumes in the NLM collection are printed on acidic paper
that could benefit from deacidification using the Bookkeeper process.
The life of these volumes would be extended 3 to 5 times and \$130
million dollars in microfilming costs would be saved by instituting a
program of deacidification. We are proposing a program to deacidify the
acidic volumes in the NLM collection over a period of 25 years. The
project would be phased in. Ten thousand volumes would be deacidifed in
the first year of a five year contract. By the final year maximum
production of 40,000 volumes would be achieved. This would cost
\$180,000 for the first year, increasing to approximately \$720,000 per
year when fully funded. The estimated contract cost includes processing
activities onsite at NLM by Bookkeeper. Bookkeeper personnel would
select, pack, ship, check in and update records for the volumes at NLM.
As part of the selection for treatment review, information about the
volumes examined, such as brittle paper, damage, etc., will be collected
and available for use in selecting materials for other preservation
activities.

As is the case for microfilming brittle volumes, priority for
deacidification would be given to serials indexed in [Index
Medicus]{.underline} and its precursors. Higher priority would be given
to older serials in HMD and B3 stacks area because they will become
brittle much sooner than more recent serials. Slightly glossy paper
should be included in the project, but we would closely monitor results
and revise selection criteria as necessary to make sure we are selecting
those that benefit from treatment. Selecting the slightly glossy paper
that can be treated now is more efficient than making another pass
through the collection to identify it later. A sample of new
acquisitions should be tested for acidity on a regular basis to
determine whether a high percentage of medical publications continue to
be printed on alkaline paper and to identify titles that will need
treatment in the future. Both volumes and records would be labeled to
indicate that the volumes were deacidified. Close monitoring of treated
volumes by pH testing upon receipt and at 5 year intervals will assure
us of the efficacy of the process.

pH BEFORE AND AFTER TREATMENT

  -------------------------- ----------- ----------- --------- --------------
  **Call Number**            **Year**    **pH        **pH      **Difference
                                         Before**    After**   in pH**

  1995 C-851                 1994        6.51        10.17     3.66

  1995 J-244                 1994        4.71        9.33      4.62

  2000 D-473                 1997        6.15        10.04     3.89

  AA6430                     1981        4.81        9.25      4.44

  AA8378                     1982        4.47        9.64      5.17

  B591                       1974        4.38        9.55      5.17

  BF 371 F691L 1965          1965        4.15        10.02     5.87

  DD5642                     1984        4.59        9.59      5.00

  E150                       1967        4.87        9.05      4.18

  EE3483                     1979        4.44        9.88      5.44

  EE6184                     1985        4.89        9.47      4.58

  EE6758                     1985        3.97        8.98      5.01

  EE7206                     1986        4.91        8.52      3.61

  F671                       1967        3.91        8.81      4.90

  F814                       1978        6.20        9.94      3.74

  GG3799                     1972        4.61        8.51      3.90

  GG5290                     1988        4.39        7.09      2.70

  HA 201 G326 1980           1980        4.31        9.12      4.81

  HV 2430 N277f 1967         1967        5.16        10.02     4.86

  QH 405 P779d 1974          1974        4.49        9.70      5.21

  QH 581 G139a 1957          1957        3.37        9.44      6.07

  QT 180 B534e 1948          1948        3.83        9.24      5.41

  QT 265 S871n 1953          1953        3.86        9.92      6.06

  QV 132 M466v 1952          1952        4.19        9.50      5.31

  QW 4 F699m 1976            1976        4.04        9.83      5.79

  QZ 202 M119c 1954          1954        4.91        9.96      5.05

  T479                       1967        3.87        9.56      5.69

  W 19 B879g 1978            1978        4.45        10.03     5.58

  W 275 FA1 M18 1982         1982        4.22        9.79      5.57

  W1 A1138K                  1974        4.31        9.48      5.17

  W1 AC422                   1974        5.07        9.43      4.36

  W1 AC863B                  1969        4.89        10.02     5.13

  W1 AC9553                  1982        4.80        9.40      4.60

  W1 AC982                   1978        4.94        9.41      4.47

  W1 AD115F                  1988        4.85        9.79      4.94

  W1 AM352                   1976        4.60        9.54      4.94

  W1 AN231                   1982        4.76        9.59      4.83

  W1 AN77                    1956        3.90        8.73      4.83

  W1 AR231                   1921        4.30        8.86      4.56

  W1 AR255                   1922        4.43        10.01     5.58

  W1 AR255                   1923        4.48        10.05     5.57

  W1 AR255                   1923        4.74        9.92      5.18

  W1 BI451                   1978        4.71        9.28      4.57

  W1 BI672                   1985        4.47        7.49      3.02

  W1 BI754L                  1977        4.80        10.09     5.29

  W1 BI876M                  1996        4.23        9.49      5.26

  W1 BI876M                  1996        4.86        9.70      4.84

  W1 BU842                   1988        4.11        9.55      5.44

  W1 CH982AB                 1986        4.49        9.71      5.22

  W1 CU132I                  1972        4.34        9.21      4.87

  W1 EK283                   1979        4.29        9.36      5.07

  W1 EU446                   1961        4.91        9.52      4.61

  W1 FO128R                  1974        5.09        8.98      3.89

  W1 FO22                    1980        5.10        9.65      4.55

  W1 FO685I                  1983        4.42        10.31     5.89

  W1 HE4705                  1974        5.02        9.59      4.57

  W1 HU426                   1969        3.71        8.88      5.17

  W1 I245                    1968        4.91        10.21     5.30

  W1 JA205DK                 1915        4.61        9.49      4.88

  W1 JO212                   1975        2.84        9.20      6.36

  W1 JO212                   1975        3.83        9.70      5.87

  W1 JO674D                  1951        4.53        10.02     5.49

  W1 JO674D                  1952        3.83        8.88      5.05

  W1 JO874                   1983        4.07        10.17     6.10

  W1 JO874                   1984        4.32        9.95      5.63

  W1 JO939P                  1969        3.94        8.56      4.62

  W1 JO939P                  1969        4.35        10.04     5.69

  W1 JO966C                  1988        4.38        9.51      5.13

  W1 JO966C                  1988        4.53        8.28      3.75

  W1 KA411H                  1974        3.93        8.74      4.81

  W1 KA411H                  1974        4.02        9.07      5.05

  W1 KH45                    1983        3.43        7.68      4.25

  W1 KH45                    1983        3.73        9.43      5.70

  W1 KO282N                  1988        4.38        9.60      5.22

  W1 KO282N                  1988        4.50        6.41      1.91

  W1 KY9927                  1994        3.55        9.40      5.85

  W1 KY9927                  1996        3.73        9.35      5.62

  W1 LE334N v.14 1981        1981        4.53        9.12      4.59

  W1 LE955                   1974        3.92        10.13     6.21

  W1 LE955                   1975        3.88        9.74      5.86

  W1 LI62                    1939        3.80        9.33      5.53

  W1 LI62                    1940        4.05        9.33      5.28

  W1 ME15                    1964        4.24        6.82      2.58

  W1 ME15                    1964        5.09        9.52      4.43

  W1 ME158Q                  1979        4.60        9.70      5.10

  W1 ME158Q                  1981        4.71        9.53      4.82

  W1 NA944N                  1968        4.71        8.66      3.95

  W1 NA944N                  1969        4.42        9.86      5.44

  W1 NE204                   1982        4.19        9.18      4.99

  W1 NE204                   1983        4.55        10.31     5.76

  W1 NI928M                  1960        3.76        6.86      3.10

  W1 NI928M                  1960        3.88        9.24      5.36

  W1 OR877                   1976        3.96        9.48      5.52

  W1 OR877                   1976        4.11        7.23      3.12

  W1 PA968                   1976        3.76        6.57      2.81

  W1 PA968                   1976        4.95        9.71      4.76

  W1 PR242                   1978        3.64        8.68      5.04

  W1 PR242                   1978        3.75        9.19      5.44

  W1 PR242                   1981        3.37        9.26      5.89

  W1 PR242                   1981        3.40        9.39      5.99

  W1 PR577K                  1977        4.22        9.44      5.22

  W1 PR577K                  1977        4.30        10.32     6.02

  W1 RO991                   1956        3.51        8.39      4.88

  W1 SC642R                  1985        5.00        9.34      4.34

  W1 SO104H                  1977        5.11        9.64      4.53

  W1 SO104H                  1978        4.95        9.10      4.15

  W1 ST439                   1972        4.96        9.67      4.71

  W1 ST439                   1975        4.61        10.11     5.50

  W1 TE637                   1980        4.87        9.80      4.93

  W1 TE637                   1980        4.90        9.32      4.42

  W1 TS278B                  1985        3.91        8.31      4.40

  W1 TS278D                  1966        3.99        9.28      5.29

  W1 UN101H                  1983        4.51        9.63      5.12

  W1 UN101H                  1984        4.93        9.67      4.74

  W1 VE821                   1991        4.36        9.86      5.50

  W1 VE821                   1991        4.45        9.35      4.90

  W1 VE841                   1974        3.29        9.03      5.74

  W1 VE841                   1975        4.10        9.92      5.82

  W1 VO6405                  1992        4.17        8.09      3.92

  W1 VO6405                  1992        4.22        7.01      2.79

  W1 WE998                   1972        4.68        9.02      4.34

  W1 WE998                   1973        5.04        9.28      4.24

  W1 YA444M                  1985        5.13        9.51      4.38

  W1 YA444M                  1987        5.11        9.21      4.10

  W1 ZA766                   1996        4.29        10.05     5.76

  W1 ZA766                   1997        4.33        9.11      4.78

  W1 ZU787                   1967        4.72        10.03     5.31

  W1 ZU787                   1967        5.07        9.54      4.47

  W3 C484                    1948        3.80        9.44      5.64

  W3 LI435P 1964d            1964        4.45        9.39      4.94

  W3 NA439N 1973f            1973        5.33        10.03     4.70

  W3 NU36 no.12 1983         1983        4.88        9.66      4.78

  WA 18 U573he 1958          1958        4.21        9.54      5.33

  WA 30 D584a 1976           1976        3.69        9.85      6.16

  WA 300 U58r 1985           1985        5.46        9.63      4.17

  WA 390 L614p 1970          1970        4.18        9.93      5.75

  WB 143 S293m 1968          1968        3.72        8.89      5.17

  WB 430 M434i 1975          1975        3.91        9.35      5.44

  WD 308 M4887 1987          1987        4.87        9.28      4.41

  WD 712 R399t 1966          1966        4.23        9.80      5.57

  WG 140 M359r 1976          1976        4.33        9.34      5.01

  WM 270 S933 1974           1974        3.79        9.82      6.03

  WM 400 Z43i 1928           1928        4.49        8.33      3.84

  WM 412 E375 1985           1985        4.14        9.82      5.68

  WM 420 P778g 1973          1973        4.36        7.93      3.57

  WM 420 W848t 1967          1967        4.01        8.88      4.87

  WM 460 C456 1978           1978        5.24        9.83      4.59

  WM 475 A313f 1967          1967        4.18        8.11      3.93

  WM 615 F889h 1962          1962        3.69        9.66      5.97

  WO 192 R751m 1944          1944        4.30        9.81      5.51

  WO 75 P944 1980            1980        6.58        8.35      1.77

  WS 107 B264m 1974          1974        3.89        9.82      5.93

  WX 150 P459e 1969          1969        4.05        9.51      5.46

  WX 157 B393b 1980          1980        4.19        10.11     5.92

  WX 159 R167w 1978          1978        5.20        9.52      4.32

  WY 159 W872c 1981          1981        6.65        9.73      3.08

  WY 20.5 R357r 1987         1987        5.29        10.04     4.75

  WY 26.5 C7365 1981         1981        4.37        9.43      5.06

  WZ 100 M8918M 1969a        1969        4.92        9.90      4.98

  WZ 100 R253P 1989          1989        4.11        9.61      5.50

  WZ 290 B418t 1983a         1983        3.96        9.83      5.87

  WZ 350 R161t 1964          1964        5.16        8.21      3.05

  Y417                       1977        5.48        9.44      3.96

  ZQU 55 A518                1976        5.60        9.77      4.17
  -------------------------- ----------- ----------- --------- --------------

[^1]: The Library of Congress considers paper testing in the range of
    6.8-7.2 to be neutral.

[^2]: The Library of Congress established this range at a time they were
    testing a variety of deacidification processes. The lower number was
    chosen because they felt that if a book is improved from highly
    acidic to about neutral that is a successful treatment. The upper
    number was chosen because their testing has indicated that there is
    no danger of damage due to high pH below that number.

[^3]: Although the Library of Congress specifications call for a minimum
    of 1.5, they now consider 1.2 to acceptable and will be changing
    their specifications.