Mould is gross and easy to spot, particularly when it comes to food. In the case of weed, it’s very different (but still gross). If a person finds an old joint under the couch, should he or she toss it out? Are there risks to smoking moldy weed?

Sadly, mould is never a good thing to inhale, no matter how much a person is jonseing for a puff. Inhaling mould could pose some health hazards to the lungs, increasing the odds of coughing and perhaps then developing a lung infection.

For people who are allergic to mould, smoking could result in inflamed sinuses and lungs. This, in turn, could produce symptoms such as sinus pain, wheezing and congestion.

In rare instances, people who are sensitive to mould could experience a fungal infection in their lungs or throats, which could be far more serious, particularly if the affected individual is immunocompromised.

Recognizing mould in weed isn’t as easy as recognizing it in food. In marijuana, it usually appears as a greyish or white coating, which some might confuse with trichomes. Upon closer examination, however, mould can look like fuzz, spots or even slime.

For all users, the easiest way to tell if weed is moldy is to give it a sniff. Mould has a distinctive smell, one that will cloud marijuana’s natural aroma. It is likely to musty and unpleasant, unlike skunky cannabis that hasn’t yet expired.

The best way to avoid moldy weed is to buy products from a certified dispensary and to always check any expiration date. The closer the weed is to this date, the more likely it could be contaminated by mould.

To prevent mould, proper storage of pot is key. Keep cannabis in a cool and dark place, sealed in an airtight container.