CDL Hazardous Materials Endorsement (HME)Emergencies and AccidentsHard
A driver is transporting Division 2.3 Poisonous Gas (e.g., Anhydrous Ammonia, UN1005). There is an accident involving a breach of the container, and the gas is visibly escaping. What is the MINIMUM initial evacuation distance, in all directions, as recommended by the ERG for a large spill/leak of this material during daytime conditions?
- A100 feet
- B1/2 mile (approximately 2,640 feet)
- C500 feet
- D1 mile (approximately 5,280 feet)
Show answer & explanationAnswer & explanation
Correct answer: B. 1/2 mile (approximately 2,640 feet)
For a large spill/leak of Division 2.3 Poisonous Gas like Anhydrous Ammonia (UN1005), the ERG (specifically Guide 125 for Anhydrous Ammonia) recommends an initial isolation distance of at least 1/2 mile (approximately 2,640 feet) in all directions during daytime. This is due to the high toxicity and potential for wide dispersion of poisonous gases.
Why the other options are wrong
- A. 100 feet is far too small for a poisonous gas leak.
- C. 500 feet is insufficient for a large release of a highly toxic gas.
- D. 1 mile might be recommended for very specific, extremely hazardous materials or for downwind protection zones, but 1/2 mile is the initial isolation for this scenario.
Poisonous Gas (Div 2.3) Evacuation
Initial isolation distances specified by the ERG for large spills of Division 2.3 Poisonous Gases, emphasizing the need for significant protective zones.
- Highly toxic and can spread rapidly.
- Distances vary by material, quantity, and time of day.
- ERG provides specific guides for each UN number.
Memory trick: Poisonous gas is far and wide, 1/2 mile to the safe side!