ATSDR / Division of Toxicology and Environmental Medicine (DTEM)
Mercury
ToxFAQs: CABS
ToxFAQs: CABSTM/Chemical Agent Briefing Sheet
Arsenic
January 2006
What is arsenic?
Arsenic is an element that is widely distributed in the earth's crust. Elemental arsenic is a steel
grey metal-like material. Arsenic is usually found in the environment combined with other
elements, such as oxygen, chlorine, and sulfur. It is released into the air by volcanoes, through
weathering of arsenic-containing minerals and ores, especially near geothermal activity, and by
commercial or industrial processes. In industry, arsenic is a by-product of the smelting process for
many metal ores, including lead, gold, zinc, cobalt, and nickel.
What are the forms of arsenic?
Arsenic is found in two forms:
•
Inorganic: Combined with elements such as oxygen, chlorine, and sulfur
• Organic: Combined with carbon and hydrogen
The inorganic forms of arsenic are more toxic than the organic ones. The table below lists
examples of the different forms of arsenic.
As0
metalloid arsenic
As3+
such as arsenites
As5+
such as arsenates
Common valence states
As3-
such as arsine gas
(CH3)2AsO(OH) cacodylic acid (dimethylarsinic acid)
CH3AsO(ONa)2 disodium methylarsenate (DSMA)
Examples of organic
arsenicals
C7H9AsN2O4
carbasone
H3AsO4
arsenic acid
Na2HAsO4
disodium arsenate
Examples of inorganic
arsenicals
NaAsO2
sodium arsenite
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ToxFAQs Chemical Agent Briefing Sheet (CABS): Arsenic
What are common products and uses of arsenic?
The table below list common products and uses of arsenic.
Commercial
products
•
antifouling paints
•
cattle and sheep dips
•
cotton desiccants
•
fire salts (multicolored flame)
•
fungicides
•
herbicides (weed killers and defoliants)
•
insecticides
•
leaded gasoline
•
paints and pigments
• wood preservatives
Industrial
processes
•
bronze plating
•
clarifying glass and ceramics
•
electronics manufacturing (microwave de