How can a person that has never had morphine or heroin be tested positive for it?

False positive test: Drug tests can produce a false positive in 5-10 percent of the time which means the test is positive even though the person did not take and drugs, and false negatives in 10-15 percent of the time. Things that can trigger a false positive for opioids are poppy seeds, quinolone antibiotic.

False positives: if it is a rapid read point of service test there can be several substances that interfere with the test. Poppy seeds can test positive for morphine type opiates. The amount of poppy seeds on a couple of bagels or a large piece of poppy seed cake may be enough to gibe a positive response to a sensitive test.