Standards and Sustainability

An examination of the history and development of recommendations for the climate in museums reveals that there was minimal scientific support for the values and ranges that were selected. The small basis of research that existed was often extended to materials or objects to which it did not apply; decisions that were merely best guesses based on minimal evidence became set in stone; and the rationale for many decisions seems to have been forgotten or twisted around. It is only relatively recently that research has provided a general scientific basis for determining appropriate values for the museum climate, especially the range in which temperature and relative humidity can be safely allowed to vary. Because the results of this research differed from what had become climatic dogma, it was criticized by some in the field. However, the results have stood up, with no substantive challenge to the data or conclusions, and are increasingly widely accepted.

David Erhardt, Charles S. Tumosa and Marion F. Mecklenburg, “Applying Science to the Question of Museum Climate,” Proceedings from Museum Microclimates, T. Padfield & K. Borchersen (eds.) National Museum of Denmark, 2007 ISBN 978-87-7602-080-4


  • a level of quality, achievement, etc., that is considered acceptable or desirable;
  • something set up and established by authority as a rule for the measure of quality


  • able to be used without being completely depleted or destroyed; able to last a long time
  • involving methods that do not completely use up or destroy natural resources

The “accepted standard” for managing the storage environment for collections has been in place since the 1970s. Based on a narrow set of environmental parameters—70° ± 4° F (20° ± 2° C) and 50 ± 3% RH—this standard was assumed to provide an ideal environment for collections in museums, libraries and archives. Although never actually established as a standard in the field of material preservation, the “70/50” or “flat line” prescription was accepted, repeated, and for the most part unquestioned.

This began to change in the 1990s. Research at preservation science laboratories in the United States, Canada, and abroad provided data to show that wider fluctuations in relative humidity and temperature were not necessarily damaging to collections. Studies of material response and behavior continued—including investigation of accelerated aging, thermal and moisture equilibration rates, and the role of temperature and moisture on various modes of decay.

Issues of sustainability came to the forefront, reflecting the growing need for institutions to be both environmentally and financially sustainable. Maintenance of the unwavering 70/50 environment was determined to be unsustainable – difficult to achieve, even harder to maintain, expensive and not always necessary. Could energy-saving practices be instituted without effecting the preservation of collections? What were the risks and how could they be managed?

The most effective solutions to the problem required the combined knowledge of individuals who design and manage climate control systems, those who best understand the role of environment in material preservation, and administrators responsible for both fiscal management and stewardship. Both the Gray Areas to Green Areas: Developing Sustainable Practices in Preservation Environments symposium in Austin, Texas and the Museum Microclimates conference at the National Museum of Denmark (both held in 2007) addressed the validity of strict environmental standards and the move toward new strategies for risk analysis and energy reduction.

Additional consideration was prompted by the National Museum Directors Conference in May 2008 which focused on Reviewing Environmental Conditions: NMDC Guiding Principles for Reducing Museum’s Carbon Footprint. The group issued a statement in 2009 that:

“Museums need to approach long-term collections care in a way that does not require excessive use of energy, while recognizing their duty of care to collections. There is general agreement that it is time to shift museums’ policies for environmental control, loan conditions, and the guidance given to architects and engineers from the prescription of close control of ambient conditions throughout buildings and exhibition galleries to a more mutual understanding of the real conservation needs of different categories of object, which have widely different requirements and may have been exposed to very different environmental conditions in the past.”

In 2010 the Canadian Conservation Institute introduced their Environmental Guidelines for Museums. They described their approach as “a departure from earlier more traditional thinking about museum environments, which called for stringent control of RH and temperature.” CCI also noted that “it is neither economical nor environmentally acceptable to have very tightly controlled conditions if they are not necessary.”

The British Standards Institution published a guideline for managing the environment for all kinds of collections in 2012 called PAS 198:2012, “Specification for managing environmental conditions for cultural collections”. No “ideal” standard was presented—the goal of PAS 198 was to help collection care professionals make informed choices based on an understanding of the role of environment in decay, the specific vulnerabilities of collection materials, the capabilities of the mechanical systems serving the space, the local environment, and the limitations imposed by the building envelope.

By this time the National Endowment for the Humanities Division of Preservation and Access was providing funds for “Sustaining Cultural Heritage Collections,” noting that:

“As museums, libraries, archives, and other collecting institutions strive to be effective stewards of humanities collections, they must find ways to implement preventive conservation measures that are sustainable. This program therefore helps cultural repositories plan and implement preservation strategies that pragmatically balance effectiveness, cost, and environmental impact. Sustainable approaches to preservation can contribute to an institution’s financial health, reduce its use of fossil fuels, and benefit its green initiatives, while ensuring that collections are well cared for and available for use in humanities programming, education, and research.”

IPI has been focused on the development of new environmental standards and tools for environmental management since the 1990s, including preservation metrics, and hardware and software for collecting and analyzing data. Partnering with the energy management consulting firm Herzog/Wheeler & Associates, IPI took their experience with material preservation research and environmental assessment into the field to explore and develop a cross-disciplinary approach between building engineers, facility managers, collection care staff, and preservation specialists. An “optimization” process developed in which energy and fossil fuel consumption, human comfort, collection vulnerabilities, and preservation quality are measured, analyzed, and prioritized in the name of sustainable preservation practice.

Although a new environmental management approach can be justified by decades of research and more recent application of sustainable practices, there is a lingering uncertainty in the field of collection care and preservation. People want to know more about the real impact a more flexible approach to environmental settings will have on collections over time. Certainly more material science research and practical application is needed.

IPI is currently working on two research projects, Demonstrating a Sustainable Energy-Saving Methodology for Library Environments, funded by the Institute of Museum & Library Services (IMLS), and Methodologies for Sustainable HVAC Operation in Collection Environments, funded by National Endowment for the Humanities (NEH). In addition, NEH has funded a third round of workshops and webinars on Sustainable Preservation Practices allowing IPI to get the word out to the field about recent research, current practices, and what you need to do to achieve a sustainable environment for preservation. Learn more about these projects at

Patti Ford, IPI Project Manager, recently created an Environmental Management and Mechanical System Quick Reference guide that consolidates the basic information needed by collection care and facilities staff working together to better improve the storage environment. Download the free PDF.

IPI also publishes “IPI’s Guide to Sustainable Preservation Practices for Managing Storage Environments”available at our online store for $25 plus shipping and handling.

The British Standards Institution’s PAS 198: 2012 is available for purchase at:

Canadian Conservation Institute environmental management guidelines are available at: