able to remove the oxides present on the metal surfaces: we proceed by placing these compounds cold on the artifacts using brushes and ending with their removal by washing in water. It will be necessary to insist with washing until you are sure that there is no acid substance left in the cavities that could ruin the treated piece. The progress made in the chemical sector in recent years has allowed the development of pickling products with biodegradable components capable of significantly reducing the ecological impact of their use. In this regard, our scientific laboratory is committed to the development of chemical products with low levels of toxicity; (no skull) to promote environmental protection.