S-130 Safety Zones 2 — Questions and Answers
Question 1: When evaluating a potential safety zone, what is the primary factor that determines whether it is large enough?
- The number of personnel who must fit inside it
- The distance from the fire's perimeter to the zone's edge
- The separation distance must equal 4 times the height of the tallest fuel (Correct answer)
- The zone must be at least one acre in size
Correct answer: The separation distance must equal 4 times the height of the tallest fuel
The standard guideline is that the separation distance from hazardous fuels to the safety zone's edge must equal at least 4 times the height of the tallest fuel.
Question 2: A firefighter notices that smoke is beginning to fill a safety zone they are sheltering in. What does this indicate?
- The fire has passed and conditions are improving
- The safety zone may be compromised and repositioning or deployment of fire shelters may be needed (Correct answer)
- Smoke in a safety zone is normal and expected
- The safety zone is large enough to absorb the smoke safely
Correct answer: The safety zone may be compromised and repositioning or deployment of fire shelters may be needed
Smoke filling a safety zone signals that the zone may no longer provide adequate protection and firefighters should prepare to deploy fire shelters or escape to another location.
Question 3: Which of the following describes a 'dynamic' safety zone?
- A pre-designated zone marked on a map before operations begin
- A zone that moves with the crew as they progress along the fireline (Correct answer)
- A zone that is only valid during daytime hours
- A permanent clearing maintained by land managers
Correct answer: A zone that moves with the crew as they progress along the fireline
A dynamic safety zone is one that moves with the crew as they work, such as a section of black (burned) area adjacent to the crew's current position.
Question 4: What is the recommended minimum size of a safety zone for a 20-person crew when flame lengths are expected to reach 50 feet?
- 0.5 acres with 100-foot separation
- 1 acre with 200-foot separation
- 4 acres with 200-foot separation (Correct answer)
- 10 acres with 500-foot separation
Correct answer: 4 acres with 200-foot separation
NWCG guidance recommends approximately 4 acres for a 20-person crew with 50-foot flame lengths, requiring about 200 feet of separation from the fuel.
Question 5: A safety zone located in a rocky outcrop on a ridgeline is considered most effective under which condition?
- When it is downslope from the fire
- When it is free of fine fuels and offers rocky, non-combustible ground (Correct answer)
- When the wind is blowing upslope toward the fire
- When surrounded by dense green vegetation
Correct answer: When it is free of fine fuels and offers rocky, non-combustible ground
Rocky outcrops are effective safety zones when they are free of fine fuels, as the non-combustible substrate prevents ground fire from entering the zone.
Question 6: Under which fire behavior condition should firefighters immediately abandon a marginally-sized safety zone and deploy fire shelters?
- When fire is more than a mile away and winds are calm
- When radiant heat becomes unbearable and flame is approaching the zone boundary (Correct answer)
- When smoke column rises vertically above the fire
- When relative humidity rises above 30%
Correct answer: When radiant heat becomes unbearable and flame is approaching the zone boundary
Firefighters should deploy fire shelters when radiant heat is unbearable and fire is approaching the safety zone boundary, as the zone can no longer provide adequate protection.
Question 7: Which term describes the area of burned fuel immediately adjacent to active fireline that can serve as a temporary safety zone?
- Green zone
- Buffer strip
- Black zone (Correct answer)
- Anchor point
Correct answer: Black zone
The 'black zone' or 'black' refers to already-burned area that has consumed its fuel and can serve as a relatively safe refuge from an advancing fire.
S-130 Safety Zones 2
When evaluating a potential safety zone, what is the primary factor that determines whether it is large enough?