Editing Orpiment (section)

== Permanence and conservation ==
Yellow orpiment (As<sub>2</sub>S<sub>3</sub>) degrades into [[arsenic oxide]]s. Because of their solubility in water, arsenic oxides readily migrate to the surrounding environment. In painted works using orpiment, migrating, degraded arsenic oxides are often detectable throughout the multi-layered paint system. This widespread arsenic migration has consequences for the conservation of orpiment as a pigment in works of art.<ref name=":4">{{Cite journal |last1=Keune |first1=Katrien |last2=Mass |first2=Jennifer |last3=Mehta |first3=Apurva |last4=Church |first4=Jonathan |last5=Meirer |first5=Florian |date=2016-04-21 |title=Analytical imaging studies of the migration of degraded orpiment, realgar, and emerald green pigments in historic paintings and related conservation issues |journal=Heritage Science |volume=4 |issue=1 |pages=10 |doi=10.1186/s40494-016-0078-1 |s2cid=40318538 |issn=2050-7445 |doi-access=free |hdl=11245.1/080e76f8-43f1-4464-afa3-8b9646e2484a |hdl-access=free }}{{Creative Commons text attribution notice|cc=by4|from this source=yes}}</ref> 

Orpiment is also sensitive to light exposure, decaying into a [[friable]] white [[arsenic trioxide]] over time. Similarly, on ancient, orpiment-coated manuscript paper in Nepal, orpiment used to deter insects has often turned white over time.{{cn|date=April 2023}}

Because of orpiment's solubility and instability as a pigment, preventing the degradation of orpiment may need to be prioritized in art conservation. Proper conservation methods should minimize exposure to strong light. Such methods should emphasize humidity control and avoid the use of water-based cleaning agents.<ref name=":4" />