Hazmat Sidebar: Fire-EMS Response to Indoor Marijuana Grows

An indoor marijuana grow is an illegal operation where the plants are grown or engineered to maturity and sold or the concentrated resin (hashish oil) is extracted from them. These operations can range from very simple to extremely complex. Marijuana grow...

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An indoor marijuana grow is an illegal operation where the plants are grown or engineered to maturity and sold or the concentrated resin (hashish oil) is extracted from them. These operations can range from very simple to extremely complex. Marijuana grow houses are structures, often urban residences and rental properties, converted for the purpose of growing marijuana. It is important to remember that first responders have been injured at these locations.

Law enforcement operations involving indoor marijuana grows have the potential to escalate into hazardous materials, fire or EMS responses. If your fire-EMS agency is dispatched to a possible indoor marijuana grow, would you know how to recognize one? What would happen if you found one? Who would you call for assistance?


Warning Signs

Warning signs for fire and EMS responders that a location possibly houses an indoor marijuana grow include:

  • Security. Unusually high numbers of “Keep Out” or “Beware of Dogs” signs may be present. High fences, locked gates, and heavy chains and locks may also be visible.
  • Smell. Indoor marijuana grows produce a heavy odor of marijuana that can be recognized outside the location. Growers may attempt to camouflage the smell with other products.
  • Condensation. Humidity in growing rooms can reach as much as 100%, producing large amounts of condensation on windows.
  • Lights. High-intensity lamps are used in indoor grows. High-intensity light can be seen around doors or windows. The building may appear much brighter than surrounding houses. This can lead to a severe fire hazard.
  • Covered windows. Windows may be covered with black plastic or heavy curtains or drapes that are closed tight and pressed against the windows. This is to prevent light from escaping and to keep natural light from disrupting artificial light cycles.
  • Open windows. Windows may be cracked open during winter to cool the house and grow room due to excess heat from high-intensity lighting.
  • Excess air conditioning units. Look for a small house with more air conditioners than would usually be needed to cool that size home and units running during winter or other periods of cooler temperatures.

These indicators are not proof that you have found an indoor marijuana growing operation, but they should raise a red flag for responders.


Fire-EMS Hazards

Hazards emergency responders may encounter at an indoor marijuana grow include:

  • Violence. Criminals who want to steal the large amounts of cash available or the profitable plants themselves have targeted indoor growing operations. This has prompted growers to arm themselves or place booby traps to protect their investments. These present a risk factor for responders.
  • Fire. Fire hazards have included exposed live wires, wire bundles, wires exposed to water or in contact with water and large numbers of high-intensity light bulbs. Also, grows may use several extra exhaust fans, which can further the spread of a fire. Numerous indoor grows have been discovered due to fires.
  • Atmospheric. One of the greatest hazards can be an oxygen-deficient atmosphere. Any atmosphere with an oxygen concentration below 19.5% or above 23.5% is dangerous. Carbon dioxide (CO2) is often artificially introduced to the indoor grow area to assist with plant growth. Flammable gas, vapor or mist in excess of 10% of its lower flammable limit (LFL) also is a hazard. Ozone (O3) generators are commonly used to reduce or eliminate the odor of an indoor grow; ozone is a known carcinogen.
  • Electrical. A residence in which an indoor grow is operating can use three to 10 times the power of an average residence. Growers will attempt to bypass the normal distribution of power and steal additional power for their operations. Those with little or no understanding of electricity typically attempt a bypass and this can create very unsafe conditions and a fire hazard. Ballasts used to run high intensity grow lights can maintain a charge for up to 15 minutes after being unplugged. Hydroponic grows combine two incompatibles – water and electricity. Numerous firefighters and law enforcement officers have been electrocuted at indoor grows.
  • Environmental. Molds present a health hazard at an indoor marijuana grow. Without respiratory protection, such mold exposure can cause allergic reactions, sinus and respiratory distress, even death in some cases. Large amounts of fungicides, pesticides, insecticides, acids and bases are stored and disposed of improperly, including being poured down drains and sewers.
  • Structural factors. Homes used for indoor marijuana grows can be altered to produce the maximum growing environment for the plants and to disguise the growing location. Walls will be moved to make room. High levels of humidity will lead to growth of dangerous fungus and molds, causing damage to insulation, walls and ceilings. Some grows have been discovered in underground rooms and tunnels. These are considered confined spaces and must be dealt with as such. Occupational Safety and Health Administration (OSHA) guidelines must be followed and only those properly trained may act as an entrant, attendant or confined-space supervisor. No other persons can make entry into this environment.
  • Hazardous materials. Many extraction techniques use flammable and volatile solvents. These can include acetones, camp fuel and isopropyl alcohol. These grows may produce many large garbage bags that are dumped illegally off site.
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