What are the minimum dimensions for an overpack?

• A. 4 mm x 4 mm
• B. 100 mm x 100 mm
• C. 500 mm x 500 mm
• D. There are no minimum dimension requirements for overpacks

Answer: (D)

Overpacks are governed by containment and marking requirements, not a fixed minimum size. The regulations don’t specify a minimum exterior dimension for an overpack; what matters is that the overpack can securely contain the inner packages, withstand normal handling and stacking, and keep all marks and labels visible and legible. Because there’s no required minimum dimension, any specific size like a tiny 4 mm x 4 mm or a large 500 mm x 500 mm isn’t mandated by the rules. The only obligation is to choose an overpack that fits the contents properly and meets strength and labeling requirements.