RBML Mold Outbreak Remediation
Nov 18, 2011
As documented through extensive press coverage, the University of Illinois at
Urbana-Champaign’s Rare Book and Manuscript Library (RBML) suffered from a mold outbreak during the
fall of 2007. The outbreak, which most likely occurred after a spike in humidity, was discovered
when one of the Library’s conservators was examining materials in the vault with the Curator of
Over the course of eight months, the staff of the RBML, Preservation & Conservation,
Library administration, and Facilities & Services worked closely to establish and implement a
remediation plan to combat the outbreak. As with any disaster, the first step taken was to control
the environment and assess the extent of the damage so that a proper response could be planned.
Temporary dehumidification was installed throughout the vault to control any humidity spikes, and
an assessment of the damage was conducted by the Library’s conservation personnel. Due to concerns
about the potential human health risks posed by the mold, the Library called in University
mycologists, who assessed minimal risk to healthy individuals, as well as positively identified the
species of mold as Aspergillus sp.
Once the mold was positively identified, Library conservators undertook an item-level
assessment, which required a total of sixty hours to complete, and provided invaluable information.
The assessment confirmed that the mold was widespread throughout the two floors of the storage
vault, and confirmed that the mold was growing on a full range of materials—vellum, leather,
paper, and cloth—and on the oldest to the most recent of the Library’s holdings. It was also
determined that mold blooms were present throughout the collection, with particularly high
concentrations near the HVAC delivery and return vents. Fortunately, the mold had not reached the
point of irreparably damaging any books or manuscripts. Given the highly distributed nature of the
outbreak throughout the collection, however, it was determined that the course of action would be
two-fold—to clean the entire collection, and the pursue support for long-term improvements to the
Upon receipt of support from the Provost’s Office for the cleaning project and approval of
emergency spending authorization, the Library began the detailed preparation for a ten-week
project. Taking advantage of the dry winter climate in central Illinois and the safeguard provided
by the use of temporary dehumidification, project plans, budgets, and estimates for both in-house
and joint in-house/outsourced models were developed and the options were weighed in order to
determine which would be the most successful in terms of both recovery and mitigation.
Determining that a joint in-house/outsourced approach was the most appropriate, Texas-based
Blackmon-Mooring-Steamatic Catastrophe (BMS CAT) was contracted to complete the cleaning of the
collection materials, storage areas, and HVAC systems over a ten-week period. In preparation for
the RBML cleaning, personnel from the Library met with the BMS CAT’s representatives, began
scheduling HVAC shut downs in preparation for the cleaning, and worked with Facilities &
Services personnel to bring a sufficient power supply into the RBML vault to support the cleaning
Following care and handling training sessions for the contracted personnel (due to the rare
and valuable nature of the Library’s collection), cleaning of the HVAC system began the week of
February 10th, 2008, under the supervision of RBML and Conservation & Preservation personnel.
The air-handling units were cleaned by HEPA vacuuming of all associated surfaces, and then wiped
down with an anti-microbial agent (Microban). After the HVAC systems were cleaned, the
structure of the library, including ceilings, floors, and walls were also vacuumed and cleaned with
an anti-microbial agent. Temporary walls were then established in the RBML vault to
compartmentalize the storage space, zones of positive and negative pressure were established to
protect cleaned areas from becoming re-contaminated, and, after training by RBML and Conservation
personnel, the item level cleaning began.
As the cleaning crew progressed through the vault, follow-up crews of Library staff addressed
problem items that the BMS CAT cleaning crews were asked to bag and pass due to fragility; replaced
pamphlet binders and clamshells that were previously identified as being particularly susceptible
to mold; and stabilized items identified as requiring remedial treatment.
The BMS CAT–contracted cleaning project concluded on May 9thwith a walk-through by BMS CAT
supervisors and representatives from the Library Administration, RBML, and Conservation. Overall,
the collections, storage furniture, and spaces were significantly cleaner than before the project
began, and visible mold growth was notably reduced. However, mold was still identified on some RBML
materials during this review. In one instance, where cleaning protocols were obviously not
followed, BMS CAT enlisted a small cleaning crew to immediately remedy the identified situation.
For other, more isolated instances, individual items are being cleaned by conservation staff as
they are identified. Some problems with shelf order have also been identified since the cleaning
In general, Conservation has felt that the process was very efficient, and could not have
been better accomplished by an in-house-only cleaning crew, and most certainly could not have been
achieved in the same time span. Though the process was exhausting for all involved in the project,
the cleaning was done as quickly and efficiently as possible and has proved a valuable learning
experience for Conservation and RBML staff alike.
The University of Illinois’ Rare Book and Manuscript Library holds approximately 300,000
volumes and over 7,100 linear feet of manuscript and archival material. The collection also
contains audiovisual media on a wide range of formats, as well as three-dimensional items,
including 150 pieces of framed artwork and various artifacts.
The variety of materials housed in the RBML presented considerable challenges for both UIUC
staff and the contracted BMS CAT cleaning crews. Warping vellum, decaying leather, fragile
paper book jackets, and the many layers within a framed work of art required a great deal of
pre-planning by UIUC staff and sensitive handling by BMS CAT crews.
The physical space also offered significant challenges for all involved. The RBML vault
comprises two floors with three separate air handling units. Electrical outlets are
non-existent in two separate areas, a dumbwaiter provides the only mechanical means for
transferring volumes between floors, and compact shelving severely limited the vendor's ability to
work multiple teams in one space at any given time.
Project Wrap Up
The BMS CAT-contracted cleaning project concluded on May 9th with a walkthrough consisting of
BMS CAT supervisors and representatives from the Library Administration, RBML and
Conservation. Overall, the collections, storage furniture and spaces were remarkably cleaner
than before the project began and visible mold growth was significantly reduced. However, mold was
still identified on some RBML materials during this review. In one instance, where cleaning
protocols were obviously not followed, BMS CAT enlisted a small cleaning crew to immediately remedy
the identified situation. For other, more isolated instances, individual items are being
cleaned by conservation staff as they are identified. Some problems with shelf order have
also been identified since the cleaning project ceased.
In general, Conservation has felt that the process was very efficient and could not have been
better accomplished by an in-house cleaning crew, and most certainly could not have been achieved
in the same time span. Though the process was harrowing and exhausting for all involved in
the project, the cleaning was done as quickly and efficiently as possible and has proved a valuable
learning experience for Conservation and RBML staff alike.
HVAC Cleaning - Before and After
The Project In Numbers
000 yards of string tie
archival pamphlet binders
pairs of gloves
sheets of binder board
pounds of microfiber cloths
gallons of Microban
Microtrap 2000 Air Filtration units
Nilfisk HEPA vacuums
Thanks to all who helped out during this project:
Book and Manuscript Library Staff
and Conservation Staff