What Clean Means

How we assess drug residue cleanup — and what a negative result can tell you.

 

Last reviewed: October 27, 2026

 

Our post-cleaning criterion

Scenesafe uses negative / not-detected results from our 8-panel screening products and ScenoMS testing as our operational post-cleaning criterion for the target drugs and sampled locations, as specified for the project. When we say “cleaned below the detection limit,” this is the scope of that statement. We do not promise zero residue.

 

As of October 27, 2026, we are not aware of any published, province-wide numerical clearance limits specifically for fentanyl or methamphetamine residues on indoor or vehicle surfaces in Nova Scotia, New Brunswick, Prince Edward Island, or Newfoundland and Labrador. We publish our own criterion so clients can understand how we assess the work. Applicable laws, project-specific requirements and directions from the responsible authority still take precedence.

 

What “not detected” means

“Not detected” on a Scenesafe report means the specified drug was not detected in the sample collected from the identified location, using the method recorded in the report, at the time of testing. It does not mean zero. Each method has a detection limit or decision threshold; a valid result below that threshold is reported as negative or not detected, according to the method.

 

A result applies to the drugs tested for and the sample collected. It does not establish the condition of every surface, rule out substances outside the test’s scope, or prove that no residue remains. No test can prove absolute zero. A negative result is evidence within the stated testing scope, not a guarantee that a vehicle or property is free of every hazard.

 

Why field results are not an exact residue measurement

Surface material, texture and porosity affect how much residue a wipe collects and how much is recovered from the sample. Laboratory analysis can provide useful quantitative results, but cannot eliminate uncertainty introduced during sampling. A surface wipe does not measure all residue within upholstery, building materials or inaccessible areas.

 

Rapid tests and mass-spectrometry methods have drug-specific response thresholds. Other substances in a sample can affect the response. Performance measured with a reference standard under controlled conditions does not automatically describe performance on every real-world surface. These limitations make precise quantification of the residue remaining after cleaning difficult.

 

Our 8-panel and ScenoMS sensitivity figures are expressed in ng/mL for the tested liquid or extract. Alberta’s laboratory wipe benchmark is expressed in ng/100 cm² of surface. A meaningful comparison requires the sampled area, extraction volume, dilution, collection and extraction recovery, and the performance of the method in that sample. A unit conversion alone does not demonstrate equivalent field sensitivity or compliance. We therefore assess our work against the negative / not-detected criterion stated above, rather than claiming a precise remaining surface concentration from a field result.

 

Guidance we reference

Alberta Health, 2020 — fentanyl. Section 6.5 describes effective remediation in terms of method-specific detection limits. It lists less than 1.0 ng/100 cm² for laboratory surface wipes and non-detectable results for TD-DART-MS and IMS. This supports the principle of method-specific non-detection; it does not establish equivalence for every test kit or instrument.

 

We reference this guidance, but do not adopt its laboratory wipe benchmark as a mandatory Scenesafe clearance limit, follow every part of its protocol, or describe our work as “certified to” or “meeting the Alberta standard.” It is guidance, not a substitute for applicable law.

 

U.S. EPA, 2021 — voluntary guidance. EPA’s fentanyl chapter draws on the Alberta guidance. EPA states that its document does not set requirements. We use it as a technical reference, not a certification scheme.

 

Methamphetamine — historical and other-jurisdiction references. NCCEH’s archived 2012 review does not establish a Canadian numerical clearance limit. It describes 0.1 µg/100 cm² as a common U.S. value at that time. Values used elsewhere vary by jurisdiction, date, method and property use. They are context, not Scenesafe’s adopted clearance criteria.

 

How we choose sampling locations

We select the number and location of samples for the conditions at each site, including the affected area, materials, suspected contamination and accessible surfaces. We do not apply a fixed sample count to every vehicle or room. A detected result calls for further assessment, additional cleaning where needed, and retesting before the affected work is accepted under our stated criterion.

 

For context, Alberta recommends about 20–30 post-remediation vehicle samples and a full repeat after detection. Its room examples of 30–40 and 50–100 samples relate to preliminary contamination assessment, not a universal post-cleaning quota. These are reference examples, not a promise that every Scenesafe project uses those counts.

 

Who performs the retesting?

When Scenesafe carries out the cleaning, our own team normally performs the post-cleaning testing. This is an internal verification of our work. It is not independent third-party clearance; Alberta’s guidance recommends an independent post-remediation assessor.

 

Clients who want a separate result have three options:

 

• Appoint their own independent testing provider to assess Scenesafe’s cleaning.

• Choose laboratory analysis of surface-wipe samples. The sampling plan, target drugs, method and reporting limits should be agreed before collection. Laboratory analysis provides a separate analytical result; independence also depends on who collects the samples and interprets the findings.

• Book Scenesafe for third-party testing after cleaning performed by another company.

 

What the report records

The report identifies the testing date and scope and includes a results table with sampling location, method, target drug or panel, and result. It explains relevant limitations and recommended next steps. Results are described using the terminology appropriate to the method, such as negative, not detected, or detected.

 

The conclusion states whether the target drugs were detected in the tested samples using the recorded methods. It applies to those sampled locations at the time of testing. It does not certify zero residue or blanket compliance with an external standard.

 

Read the original guidance

• Alberta Health: Fentanyl Remediation Guidance (2020)

• U.S. EPA: Voluntary Cleanup Guidelines (2021)

• NCCEH: Archived Remediation Review (2012)

 

Questions about a testing plan or a report? Email Scenesafe or call 902-328-4578.