Closed-head drums have a permanently attached lid with one or more small openings. What are these small openings called?

The small openings in closed-head drums are referred to as bungs. These bungs are specifically designed for filling, sampling, or dispensing contents from the drum without the need for removing the entire lid. Their design helps to maintain a sealed environment which is critical for ensuring the integrity of the contents, especially for hazardous materials or liquids that need to be kept secure from contaminants and external conditions. The bung also allows for the introduction of tools or hoses without compromising the closure of the drum. Understanding the function of bungs is vital for safety and proper handling in scenarios involving storage and transportation of materials in firefighting and hazardous material management.