What is the UN Closed Cup Flashpoint for Class 3 HazMats?

What is the UN Closed Cup Flashpoint for Class 3 HazMats?

• A. ≤200ºF
• B. ≤100ºF
• C. ≤141ºF
• D. ≤212ºF

Answer: (C)

Class 3 flammable liquids are defined by having a closed‑cup flashpoint at or below 60°C (about 140°F). The UN closed‑cup method is the standard way to determine this cutoff, and it tends to give lower flashpoint values than open‑cup tests. Since 60°C is roughly 140°F, the common rounded threshold is about 141°F in many references. So a liquid with a closed‑cup flashpoint at or below that value is classified as Class 3. That’s why the option around 141°F is correct: it reflects the 60°C (≈140°F) cutoff used to designate flammable liquids. The other numbers (far above 60°C) would place the liquid outside Class 3 classifications.

Class 3 flammable liquids are defined by having a closed‑cup flashpoint at or below 60°C (about 140°F). The UN closed‑cup method is the standard way to determine this cutoff, and it tends to give lower flashpoint values than open‑cup tests. Since 60°C is roughly 140°F, the common rounded threshold is about 141°F in many references. So a liquid with a closed‑cup flashpoint at or below that value is classified as Class 3.

That’s why the option around 141°F is correct: it reflects the 60°C (≈140°F) cutoff used to designate flammable liquids. The other numbers (far above 60°C) would place the liquid outside Class 3 classifications.