JAIC , Volume 39, Number 1, Article 7 (pp. to )
JAIC online
Journal of the American Institute for Conservation
JAIC , Volume 39, Number 1, Article 7 (pp. to )





As a result of the mold outbreak in the collection storage area, the museum staff reevaluated the control and reduction of risk in the Collection Resource Center storage area. Risk sources were identified, and risk-handling techniques were reassessed. Museum-wide understanding of response planning in a large-scale collection emergency was advanced.

The collection at the Collection Resource Center continues to be at risk until the mechanical system in the building is retrofitted to provide a reheat capability for control of relative humidity. An appropriate environment is the only assurance that this type of collection-wide mold outbreak can be prevented.


A collection-wide urgent situation may require temporary hiring outside of the museum staff. The temporary crew assembled to work on this project was a committed, hardworking, capable, and talented group of people. The museum, business, and organizational skills brought to the project by the project assistant manager and a number of crew members proved invaluable in reporting and documenting the project and treating the collection artifacts. These skills also enhanced execution of the multiple tasks asked of the crew.

Inclusion of an assistant conservator and an assistant registrar on the project staff, as originally requested by the hazard mitigation conservator, might have allowed faster completion of the mold recovery project. Project productivity and quality control would have been improved by the presence of a second conservator. Project administrative responsibilities sometimes limited the sole conservator's time for floor supervision. The presence of an assistant registrar and the requested computer support would have reduced the amount of time given to documentation by the crew.


With the conclusion of conservation-related work, the project conservator left the project in March 1997. The social history curator undertook the financial reports, the museum registrar handled procurement, and the project assistant assumed responsibility for project supervision. The project crew worked through March 1997 on collection management issues involving fine-tuning storage furniture and artifact location, documentation accuracy and filing, workstation breakdown, supply, storage, and equipment cleaning.

Organized by the project assistant, a reduced crew of four worked through mid-May 1997 labeling storage furniture, making Tyvek dust covers for shelving units, creating a comprehensive location index, and clearing up various clerical tasks.


9.4.1 9.4.1 Settling Plates

On March 11, 1997, the museum registrar placed 15 settling plates for airborne bacteria on Plate Count Agar (PCA) and for yeasts and molds on Sabouraud Dextrose Agar (SDA) throughout the Collection Resource Center, after consultation with John W. Wireman, Ph.D., of Biological Research Solutions. The plates were open in the storage area overnight. The plates were incubated at 25�C for five days. The summary of results reported that, with the exception of one site, all test sites contained from 6 to 0 colony forming units (CFU), airborne molds, or yeasts and bacteria.

For the first time in nearly two years, it was judged that the storage area could be freely entered, and personal protective equipment was no longer required. Settling plate sampling was repeated on June 25, 1998. At this time the colony forming unit levels were slightly higher than on March 11, 1997.

Settling plates cannot provide genus identification or quantitative analysis. The settling plates use gravity and ambient air movement in establishing a sample; some molds can be missed, and there is no air volume measurement.

9.4.2 9.4.2 Air Sampling

A recent publication (Tsai et al. 1999) suggests the use of zefon Air-O-Cell cassettes to recover total airborne fungal matter, including hyphae, conidiophores, and spores whether they are viable, dormant, or nonviable. Further investigation by the project conservator indicates that air sampler analysis should be conducted (Beaulieu 1998; Florian 1998; Rice 1998; Rossol 1998; Tsai et al. 1999). The project conservator is recommending to the museum that an Andersen single-stage sampler and Air-o-Cell cassettes be used at the same sites involved in the 1998 settling plate samples. It is also recommended that air sampling include a sample of the exterior air and be used in the duct coming off of each air handler, in order to meet American Conference of Governmental Industrial Hygienists (ACGIH) standards (Beaulieu 1998; Rossol 2000).

Andersen culturable samples provide proper fungal identification to species. Air-O-Cell cassettes provide an assessment of airborne fungal matter concentrations. The work can be done by a state industrial hygiene department or an industrial environment consultant. It is recommended that this laboratory analysis be regularly repeated at the semiannual change from heat-on and heat-off in the Collection Resource Center, Historic Fort Wayne, Detroit Historical Museum. ACGIH mold sampling protocol should be followed.

It should be noted that this more extensive quantitative analysis should also have been done at the time of the mold outbreak discovery in 1995. Without that data, there is no baseline against which to compare the current recommended analysis data. However, with the recommended analysis, there will now be a baseline for future analysis.

9.5 9.5 COSTS

“The insurance adjustment is concluded and the file is closed. The project file itself remains open. The storage facility mechanicals retrofit is in progress, but not yet completed. Museum administrative conservation decisions on a few artifacts have not been made. The conservation wrap-up report is pending. It is anticipated that the cost for the mold response project is in the range of $950,000.00 to $1,000,000.00. Response crew personnel wages are 75% of the total expense, supplies and materials make up 15% of the expenses. The remaining 10% includes travel and housing costs for contract conservators, supplies and materials shipping expenses, telephone, and miscellaneous costs.”


The mold outbreak in the Detroit Historical Museum Collection Resource Center storage area had several positive outcomes. There was an opportunity to examine a large amount of the Detroit Historical Museum collection. This examination resulted in artifact deaccession, documentation expansion, noncollection and hazardous materials removal, cellulose nitrate identification and appropriate storage, Native American materials clarification, archival materials relocation to more suitable storage, collection environment improvement and stabilization, long-term storage preparation, and collection access facilitation. Procedures for integrated pest management and ideas for integrating new or returning artifacts into the collection were introduced. The collection is open and available for exhibition and research.