By Joan Reinbold
Updated Mar 24, 2022
Red phosphorus is the second most common allotrope of phosphorus, known for its dark‑red appearance and low toxicity. Unlike its white counterpart, it is non‑phosphorescent and exhibits moderate chemical reactivity.
The molecule consists of tetrahedrally bonded phosphorus atoms that chain together, forming a networked structure responsible for its stability and characteristic color.
Commercially, red phosphorus is produced by heating white phosphorus in sealed containers or by exposing it to sunlight, both processes converting the highly reactive white form into the safer red allotrope.
Discovered in 1845 by Austrian chemist Anton von Schrötter, the process involved heating white phosphorus in a nitrogen‑filled flask to approximately 482 °F (250 °C) for several hours.
While red phosphorus is relatively safe for industrial use, it can be misused in illicit drug production. In methamphetamine manufacturing, it reacts with iodine to form hydriodic acid, underscoring the importance of proper handling and regulation.
For detailed safety guidelines, consult the NIOSH Pocket Guide to Chemical Hazards.
