Elemental arsenic and white phosphorus are classified as hazardous materials under DOT regulations and may trigger EPA Toxic Substances Control Act reporting obligations. Importers must ensure proper hazmat labeling, packaging certification, and may need to file a TSCA certification confirming the substance is not subject to a rule or order prohibiting its import.

Ultra-high-purity boron and arsenic used as dopants in chip fabrication are produced by a limited number of specialty chemical suppliers globally. Buyers in the semiconductor supply chain typically qualify multiple sources and maintain safety stock given the small volumes but critical nature of these inputs — a supply disruption can halt wafer production lines.