Illegal Indoor Marijuana Cultivation (IMC)

Guidance on the recognition and response considerations for illicit indoor marijuana cultivations (IMC) also called grow house. 

Overview 

Indoor marijuana cultivations includes legal and illegal operations. They range from small-scale residential setups to large commercial facilities.  This guideline is primarily intended for illegal improvised grow operations commonly found single and multi-family residences. 

PHOTO: IliictIllicit IMC including bars on the widows. [SourcePhoto Unknown]Copyright ER Playbook]

Exterior Indications of ana Possible Illegal IMC  

• Unusual buzzing sounds coming from inside the residence from light ballasts  
• Presence or sounds of fans running 
• Bright light emitting from cracks around windows and doors
• Condensation collecting on windows
• Blacked-out or heavily shaded windows
• Security inconsistent with the neighborhood including windows and doors that are fortified, or extra locks on doors or gates
• The absence of snow or frost on roofs or rooflines caused by the heat produced from grow lights
• Heat visible from the roof using a thermal imaging camera
• Skunk like odor
• Electric utility meter tampered with

Hazards

Illegal Indoor marijuana cultivation (IMC) operations contain multiple hazards, including chemicals,chemical entanglementhazards, risks,reduced oxygen environment, flammable gases, entanglement/trip hazards, structural modifications, improvised/overloaded electrical, bypassed electrical meters, mold, and criminal suspects.  Illicit operations may contain booby-traps or un secured weapons.  

PHOTO: Illustration of common hazards. [Copyright ER Playbook]

Chemicals

Chemicals are frequently present in indoor grows include:

• Fertilizers 
• Herbicides 
• Pesticides, including organophosphates  
• Fungicides
• Carbon Dioxide (CO2)CO₂) compressed gas cylinders 
• Carbon Dioxide (CO2)CO₂) gas generators 
• Sulfur burners/vaporizers 

Carbon Dioxide CO₂ Gas Generator

AlsoIndoor concerningmarijuana iscultivations theoften presenceuse ofincreased pressurizedcarbon dioxide CO₂  environments to enhance plant growth.  The additional CO₂ cylinderscan andprovided from compressed gas CO₂ cylinders, propane-powered, or natural gas powered CO₂ generators. Increased CO₂ within these tightly sealed rooms can displace oxygen, leading to asphyxiation.

PHOTO: Illustration of chemicals commonly found in illegal indoor marijuana cultivation operations and their hazards. [Copyright ER Playbook] 

Entanglement Hazards

Numerous

entanglement
• Ventilation hazardsducting
exist. Among these are ventilation ducting, exposed
• Exposed electrical wiring,wiring
electrical
• Extension cords, flexible
• Flexible plastic irrigation tubing,tubing 
• Suspension ropes and rope.cables 
Of particular concern is large-
• Large-diameter flexible ducting,ducting
which

The ventilation ducting is used in conjunction with inline ventilation fans for both intake and exhaust of air, heat and moisture from grow rooms. This ducting,often constructed of a lightweight aluminum foil laminate wrapped around small diameter helical wire, is notorious for entangling firefighters.wire. Under fire conditions, the exterior sheathing burns/melts away, leaving the helical wire exposed. In This presents a smoke-filled environment, thesesignificant entanglement hazardshazard canfor befirefighters. difficult to detect.

Electrical Hazards

OneIllegal ofIMC thecan mostpresent significanta indoorshock grow-relatedand electrocution hazards is the potential for electric shock. Due mainly to lightingresponder needs,from IMCmultiple residencessources useincluding: an

astoundamount

of
• Large electricity.number Each(20+) high-pressure sodium/metal halide lightor usesLED betweenoverhead 500lights  and
1,000
• Improvised wattsor each,exposed withelectrical awiring
typical
• Open residentialbreaker growpanels containing
anywhere
• Overloaded fromhousehold 10circuits 
• Overloaded extension cords or plug-strips
• By-passed or altered electrical meter/power feed into the structure to 40reduce overheadcosts lights.or Oneavoid ofdetection thesedue homesto high energy use. 

Illegal marijuana cultivations can consume upwards of 10,000 to 12,000 kW hours of electricity per month, nearly 20 times average household use!use. In addition, electrical equipment may be poorly wired and the home’s circuits overloaded, leading to potential shock and fire ignition sources.

By Passed Electrical Meters

Illegal marijuanatampering growor housesby-passing frequently bypassthe electrical metersmeter could resulting in standard electrical disconnect/power shut-down procedures used to powercontrol intensive,utilities 24/7during agriculturala equipmentstructure (high-intensityfire lights,or fans,emergency irrigation pumps) without generating high-usage utility bills that might alert authorities

Of great concern are bypassed electrical meters. Duefailing to eitheractually fearshut ofdown detection by electric utility company employees or in wanting to avoid paying high electricity bills, growers will bypass electrical meters. As a result, personnel at an IMC fire may secure electrical utilities only to discover there is stillthe power tofeeding into the residence.structure. If responders make contact with exposed wiring or spray hose streams onto energized equipment, there is a risk of electrocution.

Mold

Mold in grow houses is a common issue driven by the high humidity (often 80%+) and moisture required for plant cultivation. 

Illegal IMC Recognition

When conducting reconnaissance at an unknown illicit lab to determine the lab type, evaluate the propaganda, precursors, processes and products present to assist in recognizing the lab type.  Illegal indoor marijuna cultivation operations may include the following: 

See Also Clandestine Lab Recognition Process. 

Propaganda and Modus Operandi

• 420 references 
• Marijuana and THC magazines 
• Growing manuals and guides  

Precursors and Supplies 

• Carbon Dioxide cylinders or generators
• Propane cylinders 
• Sulfur generator or vaporizer
• Pesticides and herbicides  
• Plastic sheeting, plant stocks, fertilizer bags, plastic piping 
• Large amount of soil and pots acquired or discarded 
• Lumber or building supplies 

Process and Equipment

Exterior Indicators  

• UnusualAgricultural sounds coming from inside the residencechemicals (thesesee arechemical causedlist byabove) grow light ballasts and sound similar to the humming of a utility pole-mounted transformer)
• BrightHigh lightintensity emittinglighting from cracks around windows and doors
• CondensationIrrigation collectingpumps onand windowshoses (caused by high humidity in grow rooms)
• Blacked-outVentilation or heavily shaded windows that are never opened
• Windowssystems and doors that are fortified with security bars not in character with the neighborhood
• Extra locks on doors or gates that normally wouldn’t require it
• The absence of snow or frost on roofs as compared to similar homes or rooflines caused by the heat produced from grow lights
• Modified electrical meterfans  

Interior Indicators 

Products and Waste Produced

• Marijuana plants 
  • A distinctive “skunk” or “rotten cabbage-like” odor of marijuana inside or emitting from the structure 
  • Used potting buckets or soil 
  • Discarded ventilation equipment or electrical wires 

  See Also Marijuana / Cannabis 

  Response Considerations 

  HazMat Response Considerations 

  PPE Selection 

  Insulated electrical gloves 

  Air monitoring and detection 

  O2 to check for oxygen displacement 

  LEL for for flammable 

  Monitor for SO2 (consider H2S cross sensitivity) 

  CO2 monitor (do not rely on oxygen depletion alone for CO2 monitoring) 

  Pesticide testing 

  Particulate  

  Recon 

  Locate and turn off CO2 and SO2 generators 

  Determine if any other illicit processes/productions are occurring 

  Identify and Assess Chemicals Cylinders 

  Render Safe 

  Consider flaring any compromised propane cylinders 

  Eliminate ignitation sources 

  Segreate, safely stage, or overpack and chemicals of concerns

  Identify unknown chemicals 

  Decontamination 

  Structure Fire Response

  Some IMC are discovered as a result of a structure fire response. 

  Strategy Selection 

  If a IMC is suspected during size up, the IC should consider if an offensive or defensive strategy is appropriate.   In addition to standard structure fire size up considerations, the IC should consider

  Is this an occupied or unoccupied structure? 

  Can electrical utilities be secured?

  Have entanglement hazards been encountered? 

  As soon as evidence of IMC is observed, ensure that all responding personnel and the dispatch center are notified over the incident’s command and tactical channels.
  •    Broadcast an emergency alert tone notifying personnel of the hazards.
  •    Request the electrical utility company respond to verify the building’s power has been isolated.
  •    Using the above mentioned criteria, establish either an offensive or defensive strategy.
  •    Following fire knockdown, continue to wear SCBA during overhaul operations. Due to the presence of fertilizers, herbicides, pesticides and sulfur emitters, use SCBA to reduce inhalation exposures.
  •    Notify law enforcement for investigative follow up of possible criminal activity. Preserve related evidence and communicate your findings to fire investigators.

  Request a HazMat team 

  HazMat Response Considerations 

  PPE Selection 

  Insulated electrical gloves 

  Air monitoring and detection 

  Monitor for SO2 (consider H2S cross sensitivity) 

  CO2 monitor 

  Pesticide testing 

  CO2 

  Locate and turn off generators 

  Sulfur generator 

  CO2 generators 

  Identify and Assess Cylinders 

  Decontamination