THC Testing
Test properties for THC residue and contamination before occupancy, purchase, or turnover.
Heavy indoor cannabis use — and especially former grow operations — leaves marks on a property that outlast the occupants: THC residue films on walls and ceilings, residues circulated through HVAC systems, and in grow cases, moisture damage and hidden mold from sustained high humidity.
We test surfaces throughout the property for THC residue, with laboratory analysis that quantifies contamination and clearance documentation you can hand to tenants, buyers, or your property management records. Where a grow operation is suspected, we can pair residue testing with moisture and mold assessment to capture the full picture.
Why this testing matters
Rental turnovers
Property managers turning over units after heavy use get documented proof the unit is clean before the next tenant moves in.
Purchase due diligence
Buying a property with a suspected history? Testing replaces suspicion with data before you close.
Former grow operations
Grow ops combine chemical residue with sustained humidity — meaning THC testing often uncovers companion mold and moisture problems worth assessing at the same time.
Residue settles everywhere
Smoke residues deposit on walls, ceilings, carpets, and inside duct systems — far beyond the room where use occurred.
Liability protection
Documented clearance protects landlords from disputes with incoming tenants over odors and residues.
Independent lab analysis
Samples are analyzed by an accredited laboratory, producing quantified, defensible results.
What's included
- Surface wipe sampling of walls, ceilings, and fixtures
- HVAC and ductwork sampling where indicated
- Laboratory THC residue analysis
- Companion moisture/mold assessment for suspected grow sites
- Quantified results by location
- Clearance report for rentals, sales, and records
Our process
- 1
Property history review
What's known or suspected — heavy use, odor complaints, or grow-op indicators — shapes the sampling plan.
- 2
Surface sampling
Wipe samples are collected from representative surfaces in each area of concern, including HVAC components where warranted.
- 3
Laboratory analysis
An accredited laboratory quantifies THC residue levels for each sampled location.
- 4
Clearance & guidance
Your report documents conditions by area, and where cleaning is needed, defines the scope — followed by re-testing for final clearance if desired.
Frequently asked questions
The unit smells fine now — is testing still useful?
Odor fades faster than residue. Surface films persist on walls and in ducts after smells dissipate, and testing is how you document the unit's actual condition for the next occupant.
I think the property was a grow operation. What should I test?
Pair THC residue testing with a moisture and mold assessment. Grow operations run high humidity for months, and hidden mold is frequently the more expensive problem.
What do I get at the end?
A quantified, location-by-location report with clearance documentation — the kind of independent evidence that holds up with tenants, buyers, and in disputes.