What if you just inhaled majiuana from someone else?

Answer 1

Second hand high is usually a "placebo" effect, most of the THC is left in the actual "smokers" body; this makes it nearly impossible to get high off the exhaled smoke. You can have a positive UA due to second hand marijuana smoke, but you would have to been in a small closed off area with a lot of smoke. However, the federal legal cut off limit is 50 ng/ml and second hand smoke is below the cut off limit. Unfortunately, most of the instant test cups are very sensitive and will register a positive when the levels are low. That's why you must request a lab confirmation. It's called a GCMS. Before anyone can take any legal action against you for having a positive UA, they have to prove (through a lab) that your levels were higher than 50 ng/ml.