Arsenic

Arsenic is a naturally occurring chemical element with atomic number 33, prized in industry for its ability to harden metals and improve electrical properties. Though toxic, it is essential in small quantities for semiconductor manufacturing, nonferrous alloys, and pesticide production. Arsenic is traded as a commodity in global markets, with prices influenced by semiconductor demand and copper mining byproduct recovery.

Industrial use in semiconductors and alloys

Arsenic’s most valuable use is in gallium arsenide (GaAs) semiconductors. Gallium arsenide is a compound semiconductor that outperforms silicon in high-frequency applications, solar cells, and infrared devices. A tiny fraction of semiconductor wafers are GaAs rather than silicon, but the performance advantage justifies the premium cost. Military and aerospace applications drive much of the demand; commercial solar panels also rely on GaAs in multi-junction designs.

In metallurgy, arsenic is added to copper and other alloys to increase hardness and improve electrical properties. Historically, arsenic was used extensively in brass and bronze, though modern applications are narrower due to environmental and health regulations. In Asia especially, arsenic-treated copper is still used for power transmission lines and electrical components where corrosion resistance and strength matter more than toxicity concern.

Pesticides and agricultural applications

Arsenic compounds have been used for over a century as pesticides and wood preservatives. Chromated copper arsenate (CCA) was the standard wood treatment for outdoor structures until the early 2000s, when regulations restricted its use due to leaching risk. Arsenic trioxide and other compounds are still used as herbicides and insecticides in agriculture, particularly in cotton production and orchard treatments in developing countries.

Demand for arsenic in agriculture is declining in developed markets as alternatives emerge, but remains substantial in the Global South. Regulatory tightening — especially in the EU and North America — is expected to reduce this end-use further.

The supply chain: copper mining byproduct

Most arsenic is recovered as a byproduct of copper mining, not extracted directly. During copper ore processing, arsenic concentrates in the smelting residues. Recovering it requires specialized equipment and expertise; not all smelters bother, especially if copper prices are weak and arsenic demand is thin.

This supply structure creates an interesting commodity dynamic: arsenic supply is not directly controllable. It depends on global copper mining intensity, ore grades, and smelter practices. When copper prices spike and mines increase production, arsenic output rises. When copper crashes, arsenic supply shrinks even if arsenic demand is unchanged. This makes arsenic supply relatively inelastic in the short term.

Pricing and market transparency

Arsenic is less liquid than major commodities like copper or gold. There is no futures contract on major exchanges, and spot prices are quoted by specialty chemical dealers rather than transparent exchanges. Prices are typically quoted per metric ton (often in USD/MT) and vary based on purity grade (99.9% vs. 99.99%) and form (powder vs. ingot).

Historical prices have ranged from $500–2,000 per metric ton, with volatility driven by semiconductor cycles and copper production trends. The 2021–2022 semiconductor boom lifted arsenic prices; the subsequent downturn compressed them. Most transactions are bilateral between producers (smelters) and industrial consumers rather than traded on exchanges.

Environmental regulations and health risks

Arsenic is a confirmed carcinogen and the subject of strict regulation in developed countries. The US EPA limits arsenic in drinking water to 10 ppb (parts per billion). The EU classifies arsenic and arsenic compounds as category 1B carcinogens. These regulations have driven phase-outs of arsenic-treated wood and restricted pesticide use.

Recycling and disposal of arsenic-treated materials is increasingly costly and regulated. Old CCA-treated lumber in landfills represents an environmental liability; remediation efforts are underway in many countries. This regulatory tightening is a structural headwind for arsenic demand, particularly in mature economies.

China’s dominance and geopolitical risk

China is the largest producer and consumer of arsenic, accounting for roughly 40% of global production. Much of China’s arsenic is used domestically in semiconductor manufacturing and nonferrous metallurgy. Chinese regulations on arsenic emissions have tightened, but enforcement varies by region.

There is potential geopolitical risk: if China restricted arsenic exports (as it has done with rare earths), global semiconductor supply could be disrupted. Western countries’ semi-reliance on Chinese arsenic is a small but real vulnerability in the semiconductor supply chain.

Investment and speculation considerations

Arsenic is not a mainstream investment commodity. Most portfolio allocators do not carry arsenic exposure, and there is no liquid futures market to hedge. Industrial consumers and producers transact on the spot market or through forward contracts with dealers.

Small-scale speculators have little practical way to trade arsenic. The lack of liquidity, transparency, and volume makes it unsuitable for retail traders. Industry observers monitor arsenic as a leading indicator of semiconductor health and copper mining intensity, but not as a standalone speculation vehicle.