Which of the following is a safety hazard linked to uncleaned chimneys?

Chimney fires are a significant safety hazard linked to uncleaned chimneys. When creosote, a flammable byproduct of burning wood, accumulates in the chimney, it can ignite and cause a fire within the chimney structure. This type of fire can escalate quickly and potentially spread to surrounding areas, leading to significant damage and increased danger to residents. Regular chimney cleaning helps remove this buildup, significantly reducing the risk of chimney fires and ensuring safe operation of the fireplace or stove.

While mold and mildew growth, gas leaks, and water damage can also pose risks associated with chimney and fireplace systems, they are less directly tied to the condition of chimney cleanliness compared to the immediate fire risk presented by accumulated creosote. Thus, the connection between uncleaned chimneys and chimney fires is the most critical safety hazard to consider.