What can cause a false positive in chemical testing?

A false positive in chemical testing refers to an inaccurate indication that a substance is present when it is not. Legal medications and dietary habits are significant factors that can lead to false positives.

Certain legal medications have structures that may be similar to illicit drugs or can metabolize in a way that mimics the presence of banned substances. For example, some prescription medications can show up as amphetamines or opioids on a standard drug test.

Similarly, dietary habits can play a role as certain foods or supplements can trigger a false positive. For instance, consuming poppy seeds can lead to a positive result for opioids due to their natural content of morphine.

Both of these aspects illustrate how substances that are legally consumed or eaten can unintentionally affect the results of drug tests, making the correct answer encompass both legal medications and dietary habits.