Disinfestation of historical buildings – corrosion evaluation of four fumigants on standard metals

Luc Robbiola (1) , Inocencia Queixalos (2) , Antoine Zwick (2) , Katia Baslé (3) , Floréal Daniel (4) , Monique Drieux-Daguerre (5) , Patrick J F Ducom (6) , Jérôme Fritsch (7)

1 TRACES - Travaux et recherches archéologiques sur les cultures, les espaces et les sociétés
2 CEMES - Centre d'élaboration de matériaux et d'études structurales
3 CICRP - Centre Interdisciplinaire de Conservation et Restauration du Patrimoine
4 IRAMAT-CRP2A - IRAMAT-Centre de recherche en physique appliquée à l’archéologie
5 Materia Viva
6 INRA Bordeaux-Aquitaine
7 DRAAF Aquitaine - Direction Régionale de l'Alimentation, de l'Agriculture et de la Forêt Aquitaine

This study aims for providing adapted solutions for disinfestation of cultural buildings and collections in place of the use of methyl bromide, ozone depleting substance recently forbidden. It reports on a two-step corrosion test assessing the corrosive activity (corrosivity) of alternative fumigants. Four candidate fumigants are investigated: sulfuryl fluoride (SF), dimethyl disulfide (DMDS), phosphine (PH3) and cyanogen (EDN) in conjunction with five standard metals: silver (Ag), tin (Sn), iron (Fe), lead (Pb) and copper (Cu). The applied procedure is detailed including the fumigation protocol and the description of a specific electrochemical twin cells device. The surface evolution of metallic coupons after fumigation treatments and after hygrothermal ageing (35 °C, 95% RH) is compared to a blank reference series (indoor atmosphere). Results from colorimetry and electrochemical (linear sweep voltammetry) measurements, completed by Raman spectroscopy investigation show that each fumigant differently affects metals both in amplitude (amount of surface species) and in composition (nature of corrosion products). Sulfuryl fluoride (SF) can be recommended for cultural heritage but care has to be taken in presence of Pb, Sn and Cu. DMDS is also a good alternative candidate, however, it affects greatly Cu coloration and promotes Pb corrosion. Phosphine (PH3) is dramatic for Cu and has to be avoided while the efficient biocide EDN increases corrosion of Ag and Cu even if low color variation is observed. It is strongly recommended for selecting the fumigant to properly identify the metallic artefacts prior fumigation.

Mots clés: Raman spectroscopy; Spectrocolorimetry; Methyl bromide alternatives; methodology; Pollutant; Corrosion; Electrochemistry; Fumigation; Metal; Infestation

Domaines: Mécanique des matériaux [physics.class-ph]

Luc Robbiola, Inocencia Queixalos, Antoine Zwick, Katia Baslé, Floréal Daniel, et al.. Disinfestation of historical buildings – corrosion evaluation of four fumigants on standard metals. Journal of Cultural Heritage, 2015, 16 (1), pp.15--25. ⟨10.1016/j.culher.2014.02.004⟩. ⟨hal-01891721⟩