Dangerous When Wet Hazard Sign - Class 4.3 Safety Symbol Explained #76019 (License: Personal Use)

The image displays a standardized GHS/UN hazard warning label: a blue diamond with a white flame icon above the words “DANGEROUS WHEN WET” and the number 4 in the lower corner, indicating Division 4.3 of Class 4 (flammable solids). Materials labeled this way-such as alkali metals (e.g., sodium, potassium) or metal hydrides-can ignite or release explosive hydrogen gas upon contact with moisture. Proper storage requires dry, sealed environments and strict avoidance of aqueous extinguishing agents.

Used on chemical containers, transport placards, safety data sheets (SDS), and workplace signage to alert handlers, emergency responders, and logistics personnel about water-reactive hazards; aligns with OSHA, DOT, and GHS regulations.