Fentanyl is an extremely potent opioid drug sometimes sold in place of benzodiazepines, heroin and other opioids. It can be pressed into tablets or sold as a powder and in its undiluted form a fatal dose is smaller than a grain of sand.
Fentanyl is regularly found in the US and Canada but much less common in Europe
The single-use strips are used by dissolving 5 mg of powder (size of a match-head) into a teaspoon (2.5 mL) of water and submerging the test strip to the line. The test will detect any amount of fentanyl which could have an effect. For powders which may not be evenly mixed, dissolve the whole sample into 10mL of water and perform the same test. You can recover the sample by evaporation.
This contains two single-use strips. Detects fentanyl at concentrations over 0.01 μg/mL. Detects 4-FiBF, Furanylfentanyl and Acetylfentanyl over 1ug/mL (sufficient to detect dangerous amounts). The test is not intended to detect in urine but is able to do this.
Although fentanyl is the biggest concern in the UK market we currently do not know whether these tests can detect all analogues of fentanyl. As with all harm reduction techniques, testing cannot be used to guarantee safety – even pure heroin, MDMA, cocaine etc can be fatal.