Will exposure to passive marijuana smoke result in a positive marijuana test?

Perhaps the most common excuse subjects give to explain their positive marijuana test might be, “I was around some people who were smoking pot.” Research has shown, however, that casual exposure to marijuana smoke will not produce a positive test. A person really has to work at being exposed to “passive” smoke to create a positive test. Very close confinement without ventilation with several smokers for a period of over an hour may result in a low, but measurable amount of marijuana.