The Effects of Hydrogen Fluoride on the Wooden Surface of Historic Buildings during Fire Suppression Using Fluorinated Chemical Gases

ABSTRACT

Chinese historic buildings are characterized by a wooden structure, which has caused serious results due to the ravages of frequent fire disasters. After the weathering by the natural environment, the fire risk of wood is highly enlarged. Fluorinated chemical gases are widely used for fire suppression at the early stage of a historic building fire. However, the effects of hydrogen fluoride (HF) released during fire suppression on historic buildings are unavailable. Presently, experiments were performed to study HF effects on the weathered timbers. Five traditional fluorinated chemical gases, H-37, FK-5-1-12, H-1323, H-2402, and H-1301, are employed to suppress a fixed flame. The weathered timber chips, acting as historic building materials, are located in the chamber to detail the influence of HF on the surface. The characteristic of gas production and elements variety of wood surface are discussed by FTIR and SEM-EDX, respectively. It is observed that flame enhancement takes place at the early stage of fire suppression and various types of fire agents. The total amount of HF during 50 min is highly dependent on the physical parameters of fluorinated chemical gases. The SEM results of weathered timber suggest the surface of the wood is porous, resulting in a strong gas absorption performance. The amount of deposited F on the wood surface is found to be positively correlated with the total amount of HF yielded during fire suppression.

KEYWORDS:

• Corrosiveness
• fire suppression
• hydrogen fluoride
• weathered wood
• wooden culture heritage

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Key R&D Program of China No.2018YFC0807600. This work is supported by the Fundamental Research Funds for the Central Universities No.2020XJAQ03.