The significant rise in Marijuana use and the opioid epidemic is causing a need for a breathalyzer test to detect driving under the influence of drugs. While various factors such as a substance’s vapor pressure and determining the time the drug was taken are providing obstacles in the process, there is hope that a breathalyzer capable of testing for drugs is possible. Clare Waismann explains why it may be more difficult to develop a test for opioids asking, “How soon or rather how late after taking an opioid, can the test register positive for opioid intoxication? For instance, some opioids are extended release and some are immediate release. Taking this into account, how accurate would the test be for the overall situation and not the exact minute?”. Visit HowStuffWorks to read the full article.