How Safe Is Your Cannabis? The Risks Of Contamination
4 min

How Safe Is Your Cannabis? The Risks Of Contamination

4 min
Effects News

Contaminated cannabis is a problem just about everywhere. An overview of what consumers should look out for.

Legalization means lots of things, but one of the most important issues on the table just about everywhere is cannabis safety from a consumer standpoint. Some of the recent and well publicized outcry about contaminated cannabis is justified, and some of it isn’t.

In the U.S. right now, for example, cannabis safety is an issue, that appears to have been manipulated recently to try and sway the pending legalization vote in 9 states. That said, it is also a real concern. In Oregon, the state issued its first recall in late October over the higher than allowed residue of pesticides found in two batches of marijuana shipped from one farm.

In Colorado, however, there was no massive state recall last month, that supposedly killed 4 and hospitalized others. The article announcing the same (that also went viral) came from a fake news site, along with amazingly real-looking fake apologies. Earlier in the year, there was a massive recall in Colorado in March this year – over pesticide use. That said, after a retest, most of this marijuana was indeed deemed safe.

In Europe last year, in particular in the UK, for the first time in several years, there was also a large concern about contaminated cannabis, that had been apparently sprayed with glass particles.

So what are the dangers consumers need to watch out for – particularly in countries and markets where legalization and regulation are still proceeding at a snail’s pace? Beyond the dangers, that occasionally pop up in the legal market of course, is also the fact, that far too many users are still forced to rely on the black market – which is entirely unregulated.



Pesticide use is a huge concern everywhere. In U.S. states, which have passed some kind of legalization (Colorado being one of the most developed), pesticide use is carefully monitored and regulations are continually being updated and put into place. In Europe, however, as of yet, no regulated industry really exists, even though the threat here, in general, given European regulations overall, is much less of a big deal. For consumers in Italy, Croatia and Germany, the risks are relatively small right now – at least for the legit medical market. The source of the medical supply essentially guarantees, that it is either grown by the military or being imported from Canada and the Netherlands. In the U.K., it is also very likely, that the first real regulations on the industry will be imposed, as the British government regulates CBD.


Bacteria and mould on cannabis is also a huge concern. Most of this occurs during the drying and curing process, and can be harmful, particularly to those using it for medical reasons. Even in regulating Canada, this has been found to be a huge problem, at least for domestically used product. Unfortunately, however, this is one area of the cannabis business just about everywhere where few tests have been conducted on the impact of the same. What few tests have been done are fairly alarming about the health effects of such contamination in those who use it. What is on the cannabis you use goes into your body. Again, the best advice to consumers is know where your weed comes from – or grow your own. Even here, however, home growers need to cure their cannabis carefully. Marijuana is a plant and susceptible to the same decay as any other organic substance.

To protect yourself against this threat, it is best to inspect your cannabis under a black light, if you have access to one. Contaminated bud will appear to have black spots or spores or white, grey, brown or even yellow looking “fuzz”.


Contamination of cannabis and concentrates with heavy metals is also a huge concern – and from two fronts. The first is if cannabis is grown in contaminated soil. It can draw in heavy metals, that end up in the plant and what you smoke.

The other of course, comes mainly from concentrates and shatters. Because they are made with butane, improperly cooked or manufactured concentrates can retain a large amount of the production chemical. The solution? Don’t make this at home and only buy your stash from professional manufacturers, who know what they are doing.


Packaged contaminated cannabis

The other, often overlooked area where contamination is a problem, occurs in edibles and pre-packaged cannabis products. While these are not as big a market in Europe yet, in the U.S., the fact that most edibles are made up from a combination of weed sources, only adds to the problem. No contamination recalls have occurred (yet) and most of the problems this part of the industry has faced so far, are over concentrations of cannabis itself. However, dirty cannabis is likely to become an increasingly big issue in this part of the vertical too, as the entire industry continues to develop.

At a time when export also starts to become legal for medical use, how countries regulate their own industries is even more likely to be an issue, particularly in Europe – which looks to import a great deal of product from Canada over the next several years. That said, so far, governments who are authorizing such imports have picked growers with highly monitored and safe production facilities, so for the moment, this is not really a big concern.


The best way to protect yourself on all fronts is to be an active and educated consumer. As of yet, product safety labelling is extremely limited in just about every marijuana market. There are however a few guidelines to go by.

Buying a personal tester, like MyDx, can go far in allaying concerns about your cannabis. Know your source, at this point, is the only other reliable standby.


Next year, at least Germany and Spain will join the ranks of the regulating industries here – even if in the case of the German market, the product will be first subject to Canadian regulation and growing standards.

It will also be interesting to watch the impact of sovereign country regulatory oversight in markets like Australia next year. What Israel does on this front, particularly if it develops an export market, will also be interesting not only to watch, but also to see who adopts similar standards.

That said, obviously the best solution to consumers’ growing fears about the safety of the cannabis they ingest is legalization and industry regulation. With the events of the last year and the progression of the industry just about everywhere, including the bump to legalization given by the election results in the U.S. in early November, it is clear that this is also coming – and in Europe too.

The good news? The cannabis you consume is getting safer – even if the market is still in flux.


  Guest Writer  

Written by: Guest Writer
Occasionally we have guest writers contribute to our blog here at Zamnesia. They come from a wide range of backgrounds and experiences, making their knowledge invaluable.

      Find out about our writers  

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