What does black or dark grey smoke typically signify?

Black or dark grey smoke is typically a sign of incomplete combustion, which often occurs in situations where there is insufficient oxygen to fully burn the available fuel. This type of smoke indicates that the fire is burning at a high temperature due to the presence of heavy fuel sources or when the fire conditions are not optimal for full combustion. In a well-oxygenated fire, the flames would burn cleaner, producing less smoke and lighter-colored emissions. Therefore, observing black or dark grey smoke can alert firefighters and anyone else on the scene that there may be a fire that is burning inefficiently, potentially signifying impending danger and the need for additional oxygen or ventilation to control the blaze. This understanding is critical for fire response and management operations.