Reproductive problems (high incidences of miscarriage, low birth weight, congenital deformations) have also been indicated in one study of women exposed to arsenic trioxide dust as employees or neighbours of a copper foundry. In Austria, there lived the so-called "arsenic eaters of Styria", who ingested doses far beyond the lethal dose of arsenic trioxide without any apparent harm. Arsenic is thought to enable strenuous work at high altitudes, e.g. in the Alps.In the U.S., the OSHA 1910.1018 occupational permissible exposure limit for inorganic arsenic compounds in breathing zone air is 0.010 mg/m3. Production and occurrence
Arsenic trioxide can be generated via routine processing of arsenic compounds including the oxidation (combustion) of arsenic and arsenic-containing minerals in air. Illustrative is the roasting of orpiment, a typical arsenic sulfide ore.

2 As2S3 + 9 O2 → 2 As2O3 + 6 SO2Most arsenic oxide is, however, obtained as a volatile by-product of the processing of other ores. For example, arsenopyrite, a common impurity in gold- and copper-containing ores, liberates arsenic trioxide upon heating in air. The processing of such minerals has led to numerous cases of poisonings. Only in China are arsenic ores intentionally mined.In the laboratory, it is prepared by hydrolysis of arsenic trichloride:
2 AsCl3 + 3 H2O → As2O3 + 6 HClAs2O3 occurs naturally as two minerals, arsenolite (cubic) and claudetite (monoclinic). Both are relatively rare secondary minerals found in oxidation zones of As-rich ore deposits. Sheets of As2O3 stand for part of structures of the recently discovered minerals lucabindiite, (K,NH4)As4O6(Cl,Br), and its sodium-analogue torrecillasite.
For example, the Giant Mine in Canada processed substantial amounts of arsenopyrite-contaminated gold ores. References
External links
"Arsenic trioxide". Drug Information Portal. U.S. National Library of Medicine. Case Studies in Environmental Medicine: Arsenic Toxicity
"Arsenic and Arsenic Compounds". Summaries & Evaluations. International Agency for Research on Cancer (IARC). February 1998.
International Chemical Safety Card 0378
Safety Data Sheet from American Elements
NIOSH Pocket Guide to Chemical Hazards
NTP Report on Carcinogens – Inorganic Arsenic Compounds
Institut national de recherche et de sécurité (1989). "Trioxyde darsenic." Fiche toxicologique n° 89. Paris:INRS. (in French)