When must hazardous waste containers be labeled?

Hazardous waste containers must be labeled before placing any waste in them to ensure that they are identified as containing hazardous materials from the moment they begin to accumulate waste. Proper labeling is critical for safety and regulatory compliance, as it informs everyone handling the container about the potential hazards, appropriate handling procedures, and necessary precautions.

Labeling before use allows employees to recognize hazards immediately, thereby minimizing risks during storage, transportation, and handling. This practice is aligned with regulatory standards that aim to promote safe management of hazardous waste and protect workers and the environment.

The context surrounding the other choices emphasizes the importance of proactive labeling in hazardous waste management. Waiting until the container is full, as suggested in one option, could lead to dangerous situations where unmarked waste is mishandled due to lack of awareness of its contents. Labeling only at certain locations or based on specific timeframes does not address the continuous need for clear identification, compromising overall safety and potentially leading to violations of hazardous waste regulations.