Due to its high reactivity and toxicity, white phosphorus is poisonous. It can spontaneously ignite in the air, causing severe chemical burns. If ingested or inhaled, it is highly toxic. It can also contaminate the environment, making it hazardous to health and ecosystems.

Black phosphorus features a lattice structure composed of interlinked rings of six phosphorus atoms, each bonded to three others. This creates a puckered, sheet-like structure with strong interlinking, making it the most stable allotrope due to its robust and difficult-to-break bonds.

White phosphorus exhibits a glow in the dark due to chemiluminescence, resulting from its slow surface oxidation. This glowing occurs because white phosphorus is thermodynamically less stable and reacts with oxygen, producing light as it oxidises.