## 5 Conclusions  
The present study enabled us to evaluate the possible use of FAME as substitutes of more toxic solvents used in the cleaning of non-polar or low polar substances and assess their solubility power toward those materials. The tests carried out highlighted thepossibility of using FAME through a gel formulation and the customizable characteristics of FAME based on the specific material properties. Due to their minimal volatile organic compound (VOC) emissions and non-toxic nature, FAME Gels represent suitable candidates to replace organic solvents used in conservation practices, thereby helping to safeguard the health of operators. From the cleaning tests conducted, FAME were able to solubilize both microcrystalline wax and Regalrez 1094 varnish, achieving a high level of cleanliness, as evidenced by spectrocolorimetric analysis and optical microscopy observations. Gel 3 (methyl iserate) yielded the best results for oil canvases coated with microcrystalline wax, while Gels 1, 3, and 7 performed best for oil canvases coated with Regalrez 1094. Similarly, Gel 3 yielded the best results for acrylic canvases coated with both microcrystalline wax and Regalrez 1094 varnish. Methyl iserate gel emerges as the best cleaning system for removing low-polarity materials such as microcrystalline wax and synthetic varnish (Regalrez 1094). It produced excellent chromatic results and left no solvent residue on the surface after the passage with a dry cotton swab. This research contributes to the ongoing efforts in the cultural heritage conservation field to adopt sustainable practices, aligning with global initiatives for an eco-friendlier approach to artifact restoration. Conceptualization, A.M. and C.Z. ; methodology, A.M., M.F.L.R. and T.d.C. ; software, F.P. and M.F.L.R. ; validation, T.d.C. and I.A.C. ; formal analysis, C.Z., A.M. and H.A. ; investigation, C.Z., A.M., L.M. and F.I.B. ; resources, A.M. and M.F.L.R. ; data curation, C.Z. and F.I.B. ; writing--original draft preparation, C.Z. and A.M.; writing--review and editing, A.M., T.d.C. and F.P. ; supervision, A.M. All authors have read and agreed to the published version of the manuscript. This research received no external funding. Not applicable. Data availability Statement: Data are contained within the article. The author [PERSON] was employed by company Lab4 green. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. * [PERSON] et al. (2004) [PERSON]; [PERSON]; [PERSON]; [PERSON] Development and Evaluation of Removable Protective Coatings on Bronze. 2004. Available online: www.nma.gov.au (accessed on 25 September 2023). * [PERSON] et al. (2008) [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] Sample Preparation and Testing Methods for the Evaluation of Microcrystalline Waves for the Seismic Protection of Art Objects. _J. Test. Eval._**2008**, _36_, 24-33. [CrossRef]
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