Assessing the Impact of Fire Extinguisher Agents on Cultural Resource Materials

Portable fire extinguishers and their associated fire extinguishing agents play an important role in reducing the impact of fire on cultural resource collections. These may be valuable collections or the structure housing the resources which itself may be of cultural significance. A fire which can be suppressed with an extinguisher in its incipient stage will not grow to threaten adjacent materials. A range of extinguishing agents are commonly used in museums and libraries, including water, clean gaseous agents, dry chemicals, and foam. Their effectiveness in combating fires has been studied and is well-understood, but their effects on collection materials have not been adequately studied. What is less well understood is what effect these agents might have on the cultural heritage materials that are exposed to them. The primary goals of this project were to study the effects of portable fire extinguisher agents on cultural heritage materials, establish a repeatable test protocol, and assess potential cleaning methods. Eleven tests were conducted, which evaluated the following variables: exposure with and without fire, extinguisher type, material type, and sample exposure (direct vs. indirect). Thirteen materials were evaluated, which represented a wide range of the materials that can be found in cultural heritage buildings. The established test method was found to be adequate for exposing a large number of materials to the effects of extinguisher agents. These affects have been assessed on a wide range of cultural resource materials. The results indicated that, there was no single extinguisher which had no effect on all of the materials tested, even the clean agents. In fact, the corrosive effects of the thermal decomposition products from the clean agents were more pronounced in the fire tests. Several cleaning methods were also evaluated. None of the cleaning methods worked for all materials, but some worked better for certain materials. It was found that damage to samples was immediate and did not appear to progress incrementally with time. This suggests that in some cases (i.e., exposure to water mist, Halotron I and FE-36) immediate remediation may not be necessary. It is the intent that the data in this paper could be used as the foundation of an extinguisher selection matrix to be included in NFPA standards.