Eco-friendly decontamination treatments on works of art made from organic materials are of growing interest. The high risks to human health and the environment associated with traditional biocides (e.g. ecotoxicity, development of biotic resistance) have made it necessary to search for safer alternatives, also looking at the past but innovating it. The current state of the art is explored here, delving into the literature on the topic from 2000 to today, and outlining trends in terms of the most tested artistic supports and types of published research (in vitro/in vivo). An overview of the characteristics and mechanisms of biodegradation processes on different types of organic products and on the microorganisms mainly involved is thus provided. The main chemical-physical action techniques tested are illustrated and their practical-applicative aspects are discussed on the basis of evidence from case studies. Taking stock of the actual situation, literature consultation highlights that if on the one hand research is advancing rapidly towards the discovery of new ecological and safe solutions, on the other hand these are often biocidal treatments whose protocols have yet to be explored and validated.

In the context of bio-deterioration of cultural heritage, the Lavandula angustifolia Mill. plant proves to be of interest for a green approach to the preservation of art manufacts on organic media. Supercritical CO₂ fluid extraction (SFE) was utilized to obtain both lavender essential oil (E2LS3) and hydrolate (E2LS3A), while ultrasound assisted maceration in n-hexane:ethanol (99:1, v:v) provided LA2/1 extract. The extracts, all chemically characterized by UHPLC-HRMS and GC–MS analyses, were screened for their antifungal capability towards six fungi isolated from the plywood support of Haim Steinbach's contemporary artwork "Un-color becomes alter ego #2" (1984). To this purpose, disk diffusion method was applied on both mycelium and conidial suspensions to unravel whether the inhibitory activity affects the growth of fungi at different life cycle stages. The micro-atmosphere method was also explored to assess the response of fungal growth in a saturated atmosphere. Data acquired highlighted that SFE-obtained lavender essential oil, whose oxygenated monoterpene part mostly accounting for terpinene-4-ol, borneol, linalool, camphor, and 1,8-cineole, proves to be a dose- and time-dependent inhibitor of fungal growth. It has also been shown that exposure to the oil vapor phase is more effective at very low dose levels. The promising results allow us to hypothesize the use of the essential oil for treating fungal colonization by exposure to its volatile components in a modified atmosphere environment, with no direct contact with the artwork. Graphical abstract

The present work consists of an applied study on the use of lavender essential oil for the biocidal treatment of a contemporary art manufact conserved and exhibited at the Plart Museum of Plastic Arts and Design in Naples (Italy). The study consists in the proceeding of the previous in vitro trial on fungal species isolated from a contemporary artifact, in which the sensitivity of the microbial consortium to fumigation treatment by exposure to the vapor phase of the essential oil was demonstrated. The aim of this work is to compare the effectiveness of the intervention on the case study by evaluating the long-term antifungal performance of the essential oil and a commercial standard biocide based on benzalkonium chloride. The organic components of the artwork were chemically characterized using Raman and Fourier Transform Infrared Spectroscopy to assess the potential biodegradability of the different materials composing the object. Microbiological monitoring was conducted post-treatment after 1–5 months (using a bioluminometer) and after 4–8 months through new isolation. The results demonstrate that not only is the biocidal effectiveness of the fumigation treatment comparable to that of the commercial product, but it also surpasses it in terms of inhibition percentage and long-term durability.

This study introduces a pilot protocol for evaluating the environmental impact of materials used in the conservation of canvas paintings, applying a Life Cycle Impact Assessment (LCIA) approach. There are five common treatment phases: disinfection, consolidation (including paint layer softening and stabilization), varnish removal, and retouching. These interventions were assessed across three scenarios: Baseline Scenario; Scenario 1, involving material substitution; and Scenario 2, focusing on process optimization. The analysis reveals that solvent-intensive phases, particularly paint softening with Methyl Ethyl Ketone (MEK) and varnish removal using White Spirit and ethanol, have the highest environmental impacts, including climate change, ecotoxicity, and human toxicity. Biocidal treatments, although used in small quantities, also show significant toxicity impacts. Scenario 1 demonstrates that targeted substitution with lower-impact solvents can reduce key impact categories, while Scenario 2 indicates that operational improvements lead to more moderate but widespread benefits. The results confirm that even in specialized fields such as cultural heritage conservation, measurable environmental improvements are achievable through informed material choices and more efficient application practices.

In this study, a historically significant journal subject to fungal colonization was used as a case study for experimenting with a fumigation treatment using essential oils. The experiments were carried out both in vitro and in vivo directly on the artifact. Post-treatment monitoring showed that the succession of two fumigation treatments (alternately using rosemary and lavender oil) resulted in the complete disinfection of the first and second populations detected on the substrate. The latter was identified as Trichoderma longibrachiatum, a human pathogenic species, which was found to be sensitive to various concentrations of rosemary essential oil (1.2% v/v) and lavender essential oil (0.4% v/v), while it was not contained by the standard biocide based on benzalkonium chloride. The results obtained allowed the proposal of an application protocol for the fumigation of paper items that need to undergo biocidal treatment, which consists of alternating essential oils to increase the action spectrum of the natural substances and implementing a rotation principle to prevent the development of bio-resistances.