The Question:

Abandoned Building and Post-Fire HRD Search Concerns

Our Response:


Carbon Monoxide (most widely known)

Volatile Organic Compounds (VOC)

  • No limits have been established for dogs
  • Physiologically speaking one can make assumptions that the extent of exposure and absorption, along with risk for adverse reactions to volatile organics, are most likely quite different for dogs compared to people.
  • If the site hasn’t been cleared for people, dogs probably shouldn’t enter either—what would happen if the dog was allowed inside and then visually observed to go down, but the VOC levels were too high for the handler or other rescuer to enter to assist the dog?

Hydrogen Cyanide gas given off from burning of plastics and polyesters

  • Hydrogen cyanide is twenty-four times more dangerous than carbon monoxide. Because of this the action level for HCN is lower than CO.
  • The action level in order to operate without SCBA in an environment where HCN is present will be 5ppm (4.7ppm). This is the Short Term Exposure Limit (STEL) for HCN as recommended by NIOSH.
    • STEL as defined by NIOSH is a 15-minute TWA (Time-Weighted Average) exposure that should not be exceeded at any time during a workday.
    • Immediately Dangerous to Life and Health (IDLH) for HCN is 50 ppm.
  • The action level for carbon monoxide will remain the same at 35ppm. The atmosphere must meet both the action level for HCN and CO in order for personnel to operate without SCBA.


  • Assume present if older building
  • Small chips and flakes off of tiles and shingles
  • No meter for immediate detection; need filter samples sent to a lab


  • In cement, breaks down in fire, collapse
  • Requires a lab to measure

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