Most drug checking services in BC use Fourier-transform infrared (FTIR) spectrometry in combination with fentanyl and benzodiazepine test strips to check drugs at point of care sites. Substance on Vancouver Island offers additional technologies that are helpful for looking at complex samples.

You can learn more about why we use these technologies in our Drug Checking Evidence Report.

Steps in a drug check:

Only a small sample, about the size of half a matchstick head, is needed for analysis. Test results are ready in about five to ten minutes. Service is quick, free and confidential.

  • Bring samples in for testing

  • Give a small amount (the size of half a matchstick head)

  • Wait 5-10 minutes for analysis

  • Get your results

About FTIR spectroscopy

FTIR spectrometers, commonly used in forensic chemistry and the pharmaceutical industry, use infrared light to determine what compounds are in a sample. Different substances absorb the light in different patterns. By measuring how the light is absorbed by the sample, FTIR spectrometers can identify up to four or five components of a sample – including cuts or buffs that have been added to the sampled drug. Because the detection limit of FTIR is about five to ten percent, it’s important to remember that some drugs can be toxic below this concentration.


About immunoassay (test) strips

Because of the limits of FTIR spectroscopy, technicians also use fentanyl and benzodiazepine strips, which are more sensitive to their target compounds. Fentanyl test strips are very sensitive to fentanyl and some additional fentanyl analogues, but they cannot determine how much fentanyl is in a drug. They may not be able to detect all fentanyl analogues.


Benzodiazepine test strips are sensitive to a number of analogues, but not all. Like fentanyl test strips, these test strips can only detect the presence of benzodiazepines, but not how much is in a sample. Benzodiazepines can contribute to or complicate opioid overdoses, even when present in small amounts.


Find more detailed technical information about these technologies in our Technology reports.

Important things to remember

Drug checking can tell you a lot about what is in a drug sample, but it cannot tell you everything. All drug-checking technologies have limitations. To get the best analysis, most drug-checking services use more than one technology. Be aware that the FTIR and test strips may occasionally miss fentanyl, fentanyl analogues, or other harmful substances. When you get your drugs checked, the technician can explain your results and what might be missed by the technology limitations.


Drug checking can:


✅ Identify up to 4–5 substances that may be present in a sample

✅ Estimate percentages of some substances in a sample

✅ Determine whether a sample contains fentanyl and some fentanyl analogues

✅ Determine whether a sample contains benzodiazepines and some benzo analogues

✅ Help reduce risk by providing information about what is actually in a substance, allowing people to make better-informed decisions and use more safely.


Drug checking cannot:


❌ Detect substances present in small amounts (less than about 5%) using the FTIR

❌ Determine the exact percentages of what is in a sample

❌ Detect new or unknown substances that are not in our reference database

❌ Reliably distinguish between specific substances with a similar chemical make-up (e.g. 2C- family, fentanyl analogues)

❌ Determine if the whole drug intended for use is free of adulterants or contaminants.

❌ Guarantee that a drug is safe to use.

Ways to stay safe

➡️ Have a buddy or use at an Overdose Prevention Site if available.

➡️ Start low, go slow.

➡️ Use one drug at a time.

➡️ Have an overdose plan.

➡️ Carry naloxone.

➡️ Be aware of your health and tolerance.

➡️ If you choose not to use your drugs after you get them checked, the technician can safely dispose of them at the testing site.


Find more harm-reduction information at Toward the Heart.