A two-page summary of the information on arsenic contained in the 2020 UNEP Assessment Report on Issues of Concern: Chemicals and Waste Issues Posing Risks to Human Health and the Environment and the 2019 Global Chemicals Outlook II. Arsenic is a naturally occurring metalloid that is ubiquitous in the Earth’s crust. It is present in various inorganic and organic forms. Arsenic and arsenic compounds are used intentionally in wood preservatives, pesticides, animal feed additives, pharmaceuticals, glass production, alloy manufacturing, electronics, and semiconductor manufacturing.