Containers previously containing laboratory reagents are hazardous waste.

• A. Not applicable
• B. False
• C. True
• D. Not sure

Answer: (C)

The key idea is that anything that has held hazardous material can still pose a risk due to residues or vapors remaining in the container. In lab safety and waste management, a container that previously contained laboratory reagents is treated as hazardous waste unless it has been proven to be empty according to specific regulatory criteria. This means you should label it, seal it, and place it in the proper hazardous-waste accumulation area, even if you’ve rinsed it, until you have confirmed it meets the “empty container” standard (for liquids, typically drained and triple-rinsed or equivalent); until then, it must be managed as hazardous waste. This approach helps prevent exposure, spills, and environmental release. If a container truly meets the empty criteria, it may be disposed of or recycled as non-hazardous, but that determination must follow the established empty-container definitions.