Arsenic: Emissions
Why a low-value by-product carries almost no carbon
What this tab covers The greenhouse-gas footprint of the commodity at a global level, split by lifecycle phase: extraction (or farming), refining and processing, movement, usage, and recycling or end of life. Intensities are per unit of product; the global total combines intensity with world output. Also covers other environmental impacts and the main levers to cut emissions.Per t of arsenic trioxide or arsenic metal, cradle-to-gate. Intensity: not available; USGS Minerals Yearbook 2021 (unit values). Global total: not available.
Footprint by lifecycle phase
| Phase | Intensity | Share | Main sources of emissions | Notes | Source |
|---|---|---|---|---|---|
| Extraction | allocated near zero under economic allocation | – | copper, gold and cobalt-arsenide ore mining | Morocco's Bou Azzer cobalt-arsenide mine is the main exception, where arsenic is a co-product | USGS MCS 2026 (qualitative) |
| Refining / processing | not quantified: roasting and sublimation of flue dust, hydrometallurgical recovery (Guemassa), reduction to metal and zone refining | – | fuel for roasting, electricity for purification | Likely the main share of any footprint | USGS MCS 2026 (qualitative) |
| Movement | small | – | container shipping of trioxide as dangerous goods | Not material | Qualitative |
| Usage | no direct emissions | – | CCA timber treatment, herbicides, semiconductors, lead alloys | Enabling: GaAs makes efficient LEDs, RF chips and space solar cells | USGS MCS 2026 |
| Recycling / end of life | effectively none: EU end-of-life recycling input rate 0% | – | only new GaAs scrap and wood-treatment process water are recycled | CCA timber at end of life is a hazardous waste | EU CRM 2023; USGS MCS 2026 |
Other environmental impacts
Toxicity is the main issue. Smelter dust storage, CCA-treated timber disposal and leaching from mine waste can contaminate water. Rising arsenic in copper concentrates raises smelter penalties and disposal costs.
Levers to cut emissions
- Stabilise surplus arsenic as scorodite or other low-solubility forms rather than storing dust
- Replace CCA with copper-azole and quaternary preservatives (already common)
- Recycle GaAs wafer scrap and polishing residues
- Low-carbon power for high-purity refining
India
India produces no arsenic and imports small amounts (8.1% of world metal import value in 2024). Its arsenic problem is natural groundwater contamination in the Ganga-Brahmaputra basin, not supply or carbon.
Emission figures are indicative global averages from the life-cycle studies named; actual footprints vary widely by site, energy mix and method.