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

Abstract

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 (PH 3) 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 (PH 3) 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.

Non-destructive diagnosis by colorimetry of building stone subjected to high temperatures

“…Once a high resolution scan of the material absorption is available in the visible range of wavelengths, it is necessary to summarise this result in the framework of a standard colorimetric space, leading to the definition of several standard three-dimensional colorimetric spaces like, for example, RGB, HSL, XYZ, CIELuv and CIELab (Sève, 1996). The CIELab system is chosen because it is the most used in the study of materials of cultural heritage buildings (Moretto, Orsega, & Mazzocchin, 2011;Prieto, Ferrer, Sanmartín, Cárdenes, & Silva, 2011;Robbiola et al, 2015). The L* a* b* coordinate system was adopted in 1976 by the International Commission on Illumination CIE (Commission Internationale de l'Eclairage in French) as an international standard for colour measurement, and accounts for hue, saturation and lightness (Annerel & Taerwe, 2011;Ozguven & Ozcelik, 2013;Sève, 1996).…”

Analysis of the Resistance of Grain Pests to Phosphine. Review

“…Rather extensive publications are devoted to the cyanogen (CN) 2 [45,46,47,49,50,51,52,53], which established the high efficiency of this gas in suppressing insects that harm grain. However, there are indications of its phytotoxicity, which threatens the viability of the grain [41,54].…”

Wet corrosion of Al 1050 alloy in ethyl bromide-containing environment

“…As a fumigant in storage and processing plants, it has been already reported to attack aluminium even at cold temperature and in absence of moisture [2], even if no scientific reports have been published on this topic. Nevertheless, some papers on the corrosive effects of several fumigants have been already published in the open literature [33][34][35]. On the other hand, electroreduction of EtBr has been already investigated on inert metal electrodes and boron doped diamond ones in dry organic solvents and mixed organic-water mixtures, respectively [36,37].…”