The minimum dimensions for the Infectious substance hazard label are:

• A. 1 mm x 1 mm
• B. 4 mm x 4 mm
• C. 50 mm x 50 mm
• D. 400 mm x 400 mm

Answer: (C)

The rule here is about making hazard information clearly recognizable during handling and transport. The infectious substances label uses the biohazard symbol, and to ensure this symbol is legible from a distance and across different packaging sizes, regulators set a minimum square size of 50 millimeters by 50 millimeters. This size gives enough room for a consistent, noticeable symbol and any necessary text to remain readable, which helps ensure proper identification and safe handling. Smaller options would be too tiny to read or recognize, while a vastly larger size isn’t required for compliance. So the smallest compliant label dimension is 50 mm by 50 mm.