Secondary containment refers to a safety measure designed to prevent the release of hazardous materials into the environment. It involves creating a secondary barrier around a primary container, such as a tank or drum, to catch any leaks or spills. This is crucial for protecting soil, water sources, and ecosystems from contamination. Commonly used in industries that handle chemicals, secondary containment systems can include dikes, berms, or double-walled tanks. Regulations often require these systems to ensure compliance with environmental standards and to minimize risks associated with hazardous material storage and handling.