What is the maximum total quantity allowed per primary receptacle when shipping liquid Category B Infectious Substances using Packing Instruction 650?

• A. 50 mL
• B. 100 mL
• C. 500 mL
• D. 1 L

Answer: (D)

In Packing Instruction 650 for liquids that are Category B infectious substances, the amount you can put in the primary container is limited to 1 liter. This cap helps minimize the potential impact if a leak occurs, making it easier for the secondary containment and absorbent materials to contain any contents and for the outer packaging to remain intact during transport. The system requires triple packaging: a primary leak‑proof container, a secondary containment, absorbent, and a sturdy outer package. Keeping the primary receptacle to 1 liter ensures the overall package can meet these containment requirements safely. Remember that while a single primary container is limited to 1 liter, the total amount per package for liquids is further constrained (typically up to 4 liters for the whole package), so multiple primary containers can be used within one package but must stay within that total limit.