I recently received a phone call from a young lady who was worried about testing positive for marijuana on a urine test that she had to take for a job that she was applying for.

She had recently attended a concert with some friends and the people who were sitting near them were smoking marijuana and she could smell it from where she was sitting.  Second hand marijuana smoke is capable of leaving traces of THC in your urine for a day or two but usually not enough to produce a positive test result since most drug tests have cut off concentration levels where a person will not test positive for marijuana if their level of THC metabolites is lower than the cut off level.  The cut off concentration levels for most marijuana urine tests is about 50ng/ml – that is 50 nanograms per milliliter. A person who inhales second hand smoke or passive inhalation as it is sometimes referred to, may reach the 50ng/ml level but it would have to be an extreme encounter. For example, this person would have to be in car or small room with no ventilation for a sustained period of time with so much smoke it would irritate the eyes for their body to inhale enough second hand smoke to reach this level.

Staying in a well ventilated area while you are surrounded by pot or nicotine smokers is advisable if you don’t want to risk a positive results for any kind of tests including urine, hair, saliva or blood.