Arsenic

Overview

Arsenic is a semi-metal. In metallic form it is bright, silver-grey and brittle. When heated it does not melt at normal pressure but sublimes at 616 °C.¹ Arsenic compounds are toxic, and their use in products such as rat poisons and insecticides is strictly controlled.¹

Most arsenic is used as compounds in wood preservatives and pesticides. A small but strategically important share goes into high-purity metal for gallium arsenide (GaAs) and other compound semiconductors used in defense, satellites and wireless communications.² Arsenic is on the US critical minerals list and the EU critical raw materials list. It is not one of the EU's strategic raw materials.³⁴

Where it comes from

Arsenic is rarely found as the native element. The most common arsenic mineral is arsenopyrite; others include realgar, orpiment and enargite.¹ Commercially, arsenic is recovered from the flue dust of copper, gold and lead smelters and by roasting arsenopyrite. It has also been recovered from orpiment and realgar in China, Peru and the Philippines, and from copper-gold ores in Chile. In Morocco, arsenic trioxide is produced at the Guemassa hydrometallurgical complex near Marrakech from cobalt-arsenide ore mined at Bou Azzer.²

World production of arsenic trioxide was an estimated 61,000 t (gross weight) in 2025. Peru, China and Morocco, in that order, accounted for more than 95% of it. USGS believes Chile and Mexico are significant producers of commercial-grade arsenic trioxide, but neither has reported production in recent years.²

• Peru30,000 t · 49%
• China24,000 t · 39%
• Morocco5,000 t · 8%
• Belgium1,000 t · 2%
• Russia500 t · <1%

Gross weight of arsenic trioxide. World total is the rounded USGS figure. The United States had no production. Source: Mineral Commodity Summaries 2026: Arsenic

Year-end refinery capacity was about 81,000 t of arsenic trioxide, led by Peru (37,000 t) and China (30,000 t). World reserve data are not available, but USGS estimates them at more than 20 times annual world production.²

The United States has not produced arsenic trioxide or primary arsenic metal since 1985.²

What it is used for

In the United States, more than 80% of arsenic goes into herbicides, insecticides and wood preservatives. The rest goes into metallurgical and semiconductor uses.² USGS does not publish a more detailed end-use breakdown, so no end-use chart is shown.

Arsenic trioxide is mostly used to make arsenic acid, a key ingredient of chromated copper arsenate (CCA) preservatives. CCA is used to pressure-treat lumber mainly for nonresidential uses such as light poles, marine structures and retaining walls. Seven US companies produced CCA-treated wood in 2025.²

High-purity (99.9999%) arsenic metal is used to make GaAs semiconductors for solar cells, space research and telecommunications. It is also used in germanium-arsenide-selenide specialty optics and in indium gallium arsenide (InGaAs) for shortwave infrared technology. These semiconductors serve aerospace, biomedical, military, mobile and satellite applications. Lower-grade arsenic metal is used as an antifriction additive in bearings, to harden lead shot and clip-on wheel weights, and to strengthen the grids of lead-acid batteries.² Arsenic is also used to dope semiconductors and to make special glass.¹

Grades and forms

Arsenic is traded mainly as arsenic trioxide and arsenic acid, with smaller volumes of metal and other compounds. USGS converts trade data to arsenic content using fixed ratios for each compound. These ratios are shown as specs below.²

Trade and policy

The United States imports all the arsenic it uses. In 2025 it imported an estimated 6,300 t (arsenic content): 740 t as metal and 5,500 t as compounds.²

Import sources differ by product. In 2021–24, China supplied 95% of arsenic metal imports and 61% of arsenic trioxide imports, with Morocco supplying 27% of the trioxide. Malaysia supplied 99% of arsenic acid. Across all forms, the main sources were China (45%), Malaysia (30%) and Morocco (16%).² Through July 2025, China supplied more than 80% of US arsenic trioxide imports and more than 90% of arsenic metal imports.²

US import duties are low. Arsenic metal, arsenic trioxide and arsenic sulfide enter duty-free under normal trade relations, while arsenic acid and arsenic trichloride carry small ad valorem duties. There is no US government stockpile of arsenic.²

Recycling and substitution

Arsenic in new scrap from GaAs semiconductor manufacturing is recycled. Wood-treatment plants that use CCA recycle arsenic-containing process water internally. Arsenic is not known to be recovered when scrap circuit boards, relays and switches are recycled for other metals. No arsenic is recovered in the United States from residues and dusts at nonferrous smelters.²

In wood treatment, CCA can be replaced by copper-based preservatives such as alkaline copper quaternary, copper azole, copper citrate and copper naphthenate. Treated wood itself can be replaced by concrete, plastic composites or steel. In electronics, silicon competes with GaAs in solar cells and some mobile-phone amplifiers. Many makers are moving from GaAs- and silicon-based transistors to gallium nitride, and indium phosphide can replace GaAs in some infrared laser diodes. In many defense applications, there are no effective substitutes for GaAs-based integrated circuits.²

Sources

1. Arsenic: element information, properties and uses. Royal Society of Chemistry, accessed 2026-10-03. ↩ ↩² ↩³ ↩⁴

2. Mineral Commodity Summaries 2026: Arsenic. U.S. Geological Survey, accessed 2026-10-03. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵

3. Final 2025 List of Critical Minerals. Federal Register, accessed 2026-10-03. ↩

4. EU critical raw materials. European Commission, Joint Research Centre (RMIS), accessed 2026-10-03. ↩