Mercury Hazard Symbol: The Skull and Crossbones Warning

The Globally Harmonized System (GHS) hazard pictogram for elemental mercury and many mercury compounds is:

Skull and crossbones (white on black background, red diamond border)

This indicates Acute Toxicity (Category 1, 2, or 3) – fatal, toxic, or harmful if swallowed, inhaled, or in contact with skin.

Additional GHS Elements for Mercury

• Signal word: "Danger" (Cat 1,2) or "Warning" (Cat 3)
• Hazard statements: H330 (Fatal if inhaled), H310 (Fatal if skin contact), H300 (Fatal if swallowed), H372 (Causes damage to organs through prolonged exposure)
• Precautionary statements: P260 (Do not breathe dust/fume), P280 (Wear protective gloves/clothing), P301+P310 (IF SWALLOWED: Immediately call POISON CENTER), P304+P340 (IF INHALED: Remove to fresh air)

Other Relevant Pictograms

• Environment (dead fish/tree): Aquatic toxicity (Cat 1)
• Health hazard (torso): Reproductive toxicity, specific target organ toxicity
• Corrosion: For some mercury compounds

Context

Elemental mercury (thermometers, sphygmomanometers, dental amalgam) releases odorless, colorless vapor at room temperature. Chronic exposure → neurotoxicity (tremor, memory loss, erethism), nephrotoxicity. Spills require specific cleanup (sulfur powder, specialized vacuum – never regular vacuum).