🔍 Key Concepts

• Understand how butadiene is classified under the Hazardous Materials Table in 49 CFR and in the IMDG Code/IMO gas & chemical lists • Know the difference between gas vs. liquid vs. solid classifications in dangerous goods labeling • Recall that "inhibited" means a stabilizing additive has been used, but does not usually change the basic physical state classification

💭 Think About

• Ask yourself: At normal ambient temperature and pressure, is butadiene in a gaseous, liquid, or solid state? • Which one of the four choices matches the typical transport classification of butadiene in bulk or cylinders? • Does adding an inhibitor typically change a substance from a gas to a liquid/solid in its hazard class, or only stabilize it chemically?

✅ Before You Answer

• Verify the physical state of butadiene at standard temperature and pressure (STP). • Check how UN 1010 Butadiene, inhibited is listed in standard dangerous goods tables (49 CFR / IMDG). • Confirm that the word "inhibited" refers to polymerization control, not a different primary hazard class.