Which method involves placing a plastic cover or tarp over a spill of powder material?

The method that involves placing a plastic cover or tarp over a spill of powder material is known as blanketing. This technique is used to prevent the spread of a hazardous material by covering it, effectively minimizing or containing the hazard. When a spill occurs, particularly with powdered materials, it can become airborne and pose inhalation risks to responders and surrounding individuals. By applying a tarp or plastic cover, responders can stabilize the situation, limiting dispersion and exposure while they work on more permanent remediation solutions.

Covering the spill in this way is critical for both safety and environmental protection, as it helps maintain control over the hazardous materials involved. Other methods, although distinct in their approaches, do not specifically involve placing a cover or tarp directly over a spill. Damming, for instance, involves creating barriers to contain liquid spills rather than covering them, while diking refers more to constructing trenches to hold liquid contaminants.