Will I Test Positive from Second Hand Exposure?
Will I Test Positive from Second Hand Exposure?

Will I Test Positive from Second Hand Exposure?

Blog and Opinions Red Slashes Apr 1, 2019
By: CannAmm Admin

Before a drug test, there are many who fear that second hand exposure to drugs will cause them to test positive: “If I eat a poppy seed bagel, can I test positive for opiates?” or “If I’m around second hand smoke, will I test positive for THC?” And will they test positive? It is highly unlikely.

All drug tests have what is called a cut-off level. This means that the test, whether urine or oral fluid, will only look for up to a certain amount of the drug in your system. The simplest example of this is the alcohol breathalyzer test; if pulled over by the police, you are being tested with a cut off level of 0.05 BAC. So if your breath test comes under 0.05BAC, you are not considered a risk to yourself or other drivers. Suitable levels of BAC is safety-sensitive work settings are lower.

The drug tests, more specifically, are designed to have cut off levels high enough to remove the possibility of the drug test being positive due to second hand exposure. In other words, the cut off levels of any test would have to be very low in order to catch second hand exposure, like eating poppy seeds, or being around weed smokers without smoking anything yourself.



The Poppy-Seed-Defense

Research and studies have been conducted in response to this issue, as people have turned up positive results and have used what is known as the “poppy seed defense,” where they claim the positive was a result of eating poppy seeds, rather than drug consumption.

In a study published by Samano, et. al in Journal of Analytical Toxicology, participants who had consumed raw poppy seeds, and participants who had consumed a roll containing poppy seeds, were tested against the common 2000ng/ml cutoff level. Participants were tested for codeine and morphine levels via urine analysis and oral fluid testing. Poppy seeds lose about 80-90% of their opiate content during food processing, therefore it was found that consumption of raw poppy seeds (25-40g) before either an OF or urine test are more likely to produce a positive test result than prepared poppy seeds, like the ones found on bagels and in other baking.

This study’s findings also suggest that the more time you give yourself between poppy-seed consumption and an oral fluid test, the less likely you are to test positive for opiates from any form of poppy seed.  Research and studies point to the conclusion that if you were to eat a handful of raw poppy seeds the same day as an opiate drug urine or oral fluid test, then yes, you may test positive. It is unlikely but possible. However, if you were to have a bagel or roll with poppy seeds on or in it, you are even less likely to test positive for codeine or morphine (the two opiates naturally found in poppy seeds). These are based on the lab results. The final result is determined by a Medical Review Officer who will determine the impact, if any, of poppy-seed consumption.

The Canadian Model for Providing a Safe Workplace (July 2018) recommends cut off levels for the naturally occurring opiates to be much higher than the semi-synthetic opiates such as hydrocodone or oxycodone: 2000ng/ml vs. 40ng/ml.

Second Hand Smoke

When referring to the Canadian model, urine tests will result in a positive for marijuana metabolites when the urine screen is equal to or higher than 50ng/ml, and oral fluid testing looks for THC at 4ng/ml or higher on the initial screen. While these levels may seem low to the layperson, they are sufficiently high to avoid a positive result due to second-hand smoke. 

If you have any questions about the cut off levels for different substances, please contact the dedicated professionals at CannAmm.




  • Lachenmeier, D.W., Sproll, C., LM-Ch, & Musshoff, F.(2010). Poppy seed foods and opiate drug testing—Where are we today? Ther Drug Monit (32)1 p11-18
  • Kimberly L. Samano, Randal E. Clouette, Barbara J. Rowland, R.H. Barry Sample; Concentrations of Morphine and Codeine in Paired Oral Fluid and Urine Specimens Following Ingestion of a Poppy Seed Roll and Raw Poppy Seeds, Journal of Analytical Toxicology, Volume 39, Issue 8, 1 October 2015, Pages 655–661,
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