Liquid nitrogen is assigned to which class or division of dangerous goods?

• A. 9
• B. 5.2
• C. 2.2
• D. 6.2

Answer: (C)

Liquid nitrogen is treated as a gas hazard under Class 2, specifically Division 2.2, which covers non-flammable, non-toxic gases. The key idea is that the danger it presents is not flammability or toxicity, but the potential to displace oxygen and cause asphyxiation in confined spaces. That’s why it fits with other non-flammable, non-toxic gases rather than with flammable gases (2.1) or toxic gases (2.3). It isn’t an infectious substance (6.2), a miscellaneous dangerous good (9), or anything else that would place it in a different category. So the correct classification is Class 2, Division 2.2.