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Stacks Cleaning Procedures

When might you want to clean?

Whenever dust, dirt, or soot are accumulating on your collections. Construction will often require that collections be cleaned afterwards. Collection moves, shelf reading, and other collection maintenance tasks are also good opportunities for cleaning. A stacks cleaning project can benefit collections, staff, and patrons in several ways:

  • Reduce dust and dirt which can sustain or attract mold, insects, and other pests in the collections
  • Keep dust and dirt out of the interior of books, photos, tapes, and cds where it can be abrasive and cause damage over time
  • Create a pleasant working environment for both staff and patrons which also promotes respect and care for our collections and facilities


The following procedures are adapted from those at UC-San Diego and several other libraries. Their goal is to minimize both disturbance to users and damage to the collections. Vacuuming with a HEPA vacuum (available from Preservation) that effectively captures dust rather than redistributing it into the air is preferred over dusting or general vacuuming.

While stacks cleaning is very important for the collections it can be dirty and tedious work. Schedule breaks, rotate tasks, and let someone know if you are having difficulties doing the work or encountering problems with the collection. Make sure dust masks and ear plugs are easily available for people cleaning. Four hours should probably be the maximum time per day any one person spends cleaning. Stacks cleaning should always be done by a team of two people if possible – the work goes faster, easier and is less tedious if done together. By cooperating, two people should be able to vacuum three sections of books and shelving in an hour.

To reduce the need for stacks cleaning, floors should be vacuumed and/or washed regularly. Sweeping should be discouraged since it tends to scatter dust and dirt and precautions should be taken to prevent books on low shelves from being splashed by cleaning fluids. Coordinate stacks cleaning with custodial staff – stacks cleaning will be more effective if coordinated with floor cleaning.

Some things to consider before beginning stacks cleaning:

  • Be on the lookout for problems. Droppings might signal the presence of rodents or insects and mold or dampness could indicate a humidity problem or leaky pipe. If you suspect a problem, stop working and alert preservation or the mendery immediately. Do not move the items.
  • Damaged materials needing repair should not be pulled from the stacks at this time, unless there is a serious problem that needs immediate attention. Instead, record the call number(s) on a separate sheet of paper with a brief note indicating the problem.
  • Books that do not fit on the shelf should be set aside. The call number(s) of books that fit but are foreedged could be recorded on a separate sheet of paper for possible relocation in oversize.
  • Carefully remove things that have been left by patrons in books such as bookmarks, scraps of paper, paper clips, and post-it notes.


Vacuuming is preferable to dusting but if you have no choice but to dust, static dust cloths are best for gently dusting without redistributing dust. 3M MMM-2011CC5B or Dust Bunny® cloths can be ordered through Library Supplies. Chemically-treated dust cloths and dusting products like Endust, should not be used directly on books.

It is especially important when dusting that books are picked up one at a time and held firmly closed. Dust the top of the pages by dusting away from the spine toward the fore edge. Otherwise dust and dirt will enter the textblock and defeat the purpose of cleaning.


Vacuuming with a HEPA vacuum (available from Preservation) is the most effective way to clean collections. The HEPA vacuum prevents the recirculation of dust back into the air. It also has adjustable suction and a soft brush for cleaning especially fragile materials.

Step by step instructions for stacks cleaning with the Nilfisk HEPA vacuum cleaner:

  1. Equip a team of two with a step stool, book truck, a few book ends, sufficient clean cotton rags or dust cloths, a vacuum, dust masks, and earplugs.
  2. On a clipboard, log the date, time and your name. Begin at the call number finished during the last shift.
  3. Working from the top shelf of a range down, remove a few books at a time. Hand to your partner to place the books, in order, on the book truck. Be sure to support the remaining books on the shelf with a hand or bookend so they don’t fall to the floor.
  4. Vacuum the shelf (including empty shelves). Shelves that are exceptionally dirty (either dusty/dirty lower shelves or something that has been spilled like coffee) can be washed, preferably with a damp cotton rag. Be sure the shelf completely dries before reshelving the books.
  5. Leave the vacuum on while cleaning – turning it on and off frequently will burn out the motor. The Nilfisk HEPA vacuum cleaner has adjustable suction. Adjust the knob at the front according to the condition of the books you are vacuuming. In most cases, you will want to use a medium speed for books in good condition. If using a speed in the low to medium range, make sure the switch is set to “VAR.” If using a speed in the high range (for vacuuming empty shelves for example), make sure the switch is set to “FULL” and allow the vacuum to run at full speed. DO NOT leave the switch in the “VAR” position if the vacuum is going to be run at full speed — this could cause the the speed control to burn out.
  6. While one person wipes the shelf, the other person can gently vacuum the top of the books while holding the volume tightly closed and brushing away from the spine. If materials are flaking or fragile, adjust the suction and/or rubberband a piece of cheesecloth over the brush and very gently vacuum. This will prevent pieces of the book from being vacuumed up.
  7. Replace the books, in order, back on the shelf with a bookend. Make sure books are not scraping the next shelf up and that spines are flush with or within the front edge of the shelf.
  8. Move down to the next shelf. Change to a clean rag as necessary. Switch positions with the other person when you finish the bottom shelf to share the workload and to reduce the risk of repetitive motion injury. Whenever possible, handle books using the palms of your hands instead of gripping with thumb and finger. Handle a few books at a time if they are small; one at a time if they are heavy/large. Sit on the floor or stool rather than bending over to move books off the lowest shelves.
  9. At the end of a shift, record the last call number, total sections cleaned, and length of time on the clipboard. This record will aid the supervisor in compiling statistics at the end of the project and aid Preservation in estimating the time/costs needed for cleaning the collections.

10. Lock equipment up at night. When done, return equipment and supplies to Preservation.

Important instructions for the HEPA vacuum cleaner

This is an expensive piece of equipment – please follow the instructions carefully!

Leave the vacuum on while cleaning. Turning the motor on for only a few minutes at a time (e.g. after every shelf) can cause serious damage.

If using a speed in the low to medium range, make sure the switch is set to “VAR.” If using a speed in the high range, make sure the switch is set to “FULL” and allow the vacuum to run at full speed. DO NOT leave the switch in the “VAR” position if the vacuum is going to be run at full speed — this could cause the the speed control to burn out.

Changing filters:

The HEPA has 3 different filters in addition to the vacuum bags. It is important to check the bags frequently to minimize the replacement of the other filters.

  • Check the paper bag in the bottom compartment every few days or after vacuuming any significant amount of material. Change the paper bags (cost about $2 each) before they are completely full.
  • The middle compartment contains the main filter and microfilter.
    • The main filter is the large white cotton bag; it should not need to be replaced anytime soon.
    • The microfilter is the yellow felt sock that fits over the motor bottom. The microfilter (costs around $40) should be changed as soon as discoloration is noticeable.
  • The HEPA exhaust filter is mounted on top of the motor, outside the container beneath the handle. If properly maintained it should last about a year. Normally four microfilter changes equal one change of the HEPA filter (costs $130)

Additional references:

Managing a Stacks Cleaning Project – Shannon Zachary, University of Michigan in Archival Products NEWS (Volume 5, No. 1)
University of California, San Diego Stacks Cleaning Procedures by Julie Page
Cleaning Books and Shelves – Sherelyn Ogden, Head of Conservation, Minnesota Historical Society in NEDCC’s Preservation of Library & Archival Materials: A Manual