SOP 502 Flammable Vapors Methane (Natural Gas) and Propane

Question 1

What should the initial IC at any confirmed or suspected flammable gas/vapor leak do?

Answer 1

Establish command post uphill/upwind. Isolate and deny entry for 330’ for any vapor. Attempt to control all ignition sources. Evaluate needs and adapt. Ensure responsible party is notified.

Question 2

What are interior operations for flammable vapor incidents?

Answer 2

Time to see if presence of gas returns may be a viable tactic. Try to control flow and mitigate by valve control. Account for gas migration and pocketing in interior and exterior settings. Consider scene not stable until the LEL is at 0%. Elevated LEL may be ok if someone qualified to fix the problem is on scene.

Question 3

What are exterior operations for Flammable vapor incidents?

Answer 3

Do not attempt to clamp or plug a source line. Coordinate with Xcel to provide protection (Can be a handline 1.75 for residential feeders, 2.5 for commercial feeders). Do not enter trench or deploy water into trench unless a rescue is needed. Consider migrating vapors from underground sources. Same LEL rules as interior ops.

Question 4

When to do rescue or recovery strategy?

Answer 4

Same as in Haz mat SOP. must have reliable witness info or a line of sight rescue.