white arsenic

chemical compound

Also known as: arsenious oxide

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 15, 2026

Quick Summary

White arsenic, chemically known as arsenious oxide (As₄O₆), is a compound of arsenic and oxygen. It is a white, powdery substance that can be obtained as a byproduct of smelting copper, lead, cobalt, and gold ores, or by heating arsenic sulfide ores. Historically, it was recognized as one of three forms of "arsenic" by the 11th century.

White arsenic is a key starting material for many other arsenic compounds and has been used as a decolorizer in glass manufacturing and as a preservative for hides. However, it is also highly poisonous and was historically used as a poison. Arsenic poisoning can result from ingestion or inhalation of arsenic compounds and affects cellular metabolism. Symptoms range from acute gastrointestinal distress to chronic effects like skin changes and neurological issues.12

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

2 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

arsenic
Commercial production and uses
…principal forms of which are arsenious oxide (As₄O₆) and arsenic pentoxide (As₂O₅). Arsenious oxide, commonly known as white arsenic, is obtained as a by-product from the roasting of the ores of copper, lead, and certain other metals as well as by the roasting of arsenopyrite and arsenic sulfide ores. Arsenious…
Read More
…principal forms of which are arsenious oxide (As₄O₆) and arsenic pentoxide (As₂O₅). Arsenious oxide, commonly known as white arsenic, is obtained as a by-product from the roasting of the ores of copper, lead, and certain other metals as well as by the roasting of arsenopyrite and arsenic sulfide ores. Arsenious…
Read More

arsenic poisoning
…of the colourless, tasteless compound arsenious oxide as a poison was common until chemical methods of detection were developed. Definitive diagnosis of arsenic poisoning is based on the finding of arsenic in the urine and in hair or nails.
Read More
…of the colourless, tasteless compound arsenious oxide as a poison was common until chemical methods of detection were developed. Definitive diagnosis of arsenic poisoning is based on the finding of arsenic in the urine and in hair or nails.
Read More