Editing Drug test (section)

===Presumptive substance testing===
Presumptive substance tests attempt to identify a suspicious substance, material or surface where traces of drugs are thought to be, instead of testing individuals through biological methods such as urine or hair testing. The test involves mixing the suspicious material with a chemical in order to trigger a color change to indicate if a drug is present. Most are now available over-the-counter for consumer use, and do not require a lab to read results.
[[File:Duquenois Reagent.jpg|thumb|174x174px|Duquenois reagent]]
Benefits to this method include that the person who is suspected of drug use does not need to be confronted or aware of testing.  Only a very small amount of material is needed to obtain results, and can be used to test powder, pills, capsules, crystals, or organic material. There is also the ability to detect illicit material when mixed with other non-illicit materials. The tests are used for general screening purposes, offering a generic result for the presence of a wide range of drugs, including Heroin, Cocaine, Methamphetamine, Amphetamine, Ecstasy/MDMA, Methadone, Ketamine, PCP, PMA, DMT, MDPV, and may detect rapidly evolving synthetic designer drugs. Separate tests for Marijuana/Hashish are also available.<ref>{{Cite web |title=Global Synthetic Drugs Assessment |url=https://www.unodc.org/documents/scientific/2014_Global_Synthetic_Drugs_Assessment_web.pdf |access-date=October 21, 2022 |archive-date=October 21, 2022 |archive-url=https://web.archive.org/web/20221021172713/https://www.unodc.org/documents/scientific/2014_Global_Synthetic_Drugs_Assessment_web.pdf |url-status=live }}</ref>

There are five primary color-tests reagents used for general screening purposes. The [[Marquis reagent]] turns into a variety of colors when in the presence of different substances. [[Dille–Koppanyi reagent|Dille-Koppanyi reagent]] uses two chemical solutions which turns a violet-blue color in the presence of barbiturates. [[Duquenois–Levine reagent|Duquenois-Levine reagent]] is a series of chemical solutions that turn to the color of purple when the vegetation of marijuana is added. [[Ehrlich's reagent|Van Urk reagent]] turns blue-purple when in the presence of LSD. [[Scott test]]'s chemical solution shows up as a faint blue for cocaine base.<ref>{{Cite book|title = Forensic science:From the crime scene to the crime lab|last = Saferstein|first = Richard|publisher = Pearson Education Inc|year = 2013|isbn = 978-0131391871|location = Upper Saddle River|pages = 271}}</ref>

In recent years, the use of presumptive test kits in the criminal justice system has come under great scrutiny due to the lack to forensic studies, questioned reliability, rendering of false positives with legal substances, and wrongful arrests.<ref>{{Cite web|url=https://www.nytimes.com/2016/07/10/magazine/how-a-2-roadside-drug-test-sends-innocent-people-to-jail.html|title=How a $2 Roadside Drug Test Sends Innocent People to Jail|last1=Gabrielson|first1=Ryan|last2=Sanders|first2=Topher|date=16 December 2016|website=The New York Times Magazine|archive-url=https://web.archive.org/web/20161206102939/http://www.nytimes.com/2016/07/10/magazine/how-a-2-roadside-drug-test-sends-innocent-people-to-jail.html|archive-date=6 December 2016}}</ref><ref>{{Cite web|url=https://www.propublica.org/article/common-roadside-drug-test-routinely-produces-false-positives|title=Tens of thousands of people every year are sent to jail based on the results of a $2 roadside drug test.|last1=Gabrielson|first1=Ryan|last2=Sanders|first2=Topher|date=7 July 2016|website=ProPublica.org|archive-url=https://web.archive.org/web/20190316153405/https://www.propublica.org/article/common-roadside-drug-test-routinely-produces-false-positives|archive-date=16 March 2019|access-date=16 March 2019}}</ref><ref>{{Cite web|url=https://www.cacj.org/documents/sf_crime_lab/studies__misc_materials/falsepositives.pdf|title=False Positives Equal False Justice|last=Kelly|first=John|year=2008|website=California Attorney General|archive-url=https://web.archive.org/web/20190316152146/https://www.cacj.org/documents/sf_crime_lab/studies__misc_materials/falsepositives.pdf|archive-date=16 March 2019|access-date=16 March 2019}}</ref>