how to tell if weed has pesticides

Should You Fear Pesticides on Your Cannabis?

Fear can be crippling. Don’t live your life in fear.

“Pesticide” is the most serious buzzword in all of cannabis right now. It’s damn near Voldemort. The reason is, for consumers, the word has been directly linked to the thought of “dangerous cannabis.”

But before we throw up the red alert beacons about all things cannabis, let’s add a little nuance to the conversation.

What Is a Pesticide?

Pesticide is a word, not a weapon.

By definition, a pesticide is a substance used for destroying insects or other organisms harmful to cultivated plants or to animals. This means herbicides for destroying weeds, insecticides for controlling insects, fungicides to prevent mold and mildew, disinfectants to prevent the spread of bacteria, and compounds used to control mice and rats.

“When the [cannabis] plants are creating terpenes, those are basically pesticides. They’re the natural defense mechanism that the plant creates, so it’s more about the use of the word and understanding what it means for your products,” says Lo Freisen, CEO and Chief Extractor of Washington’s Heylo Cannabis, a processor that places extreme emphasis on the use of sustainably grown, pesticide-free cannabis.

Why Do People Fear Pesticides?

Some think the inhalation of pesticides is linked to health problems, such as respiratory issues and the dreaded Cannabinoid Hyperemesis Syndrome (CHS). In so many words, CHS is a condition that causes cannabis consumers to experience fits of nausea and vomiting, as well as abdominal pain. But there truly is not enough research or data to justify the connection between CHS and pesticide inhalation. Still, you don’t want to be smoking them.

“Pesticides are everywhere. We’re breathing them in the air around us. The toxicity of pesticides aren’t that high when consuming them, or eating or touching them. However, when people combust/inhale pesticides, things can become a health issue,” says Pat Reynolds, Operations Director of Confidence Analytics, a cannabis testing lab in Washington State.

Which Pesticides Do People Fear?

One of the most frequently used pesticides in cannabis production is neem oil, a naturally occurring pesticide found in seeds of the neem tree. The active component of this pesticide is azadirachtin.

Heylo’s Friesen says: “Azadirachtin comes from neem oil, and neem has been used a lot in cannabis because it’s a natural compound that’s considered organic. But there has been some anecdotal evidence that shows that this could be the reason people get sick from cannabis.”

Many consumers believe azadirachtin to be the cause of CHS, while others believe it is not CHS that consumers are experiencing, but actually azadirachtin poisoning. Both ideas remain unconfirmed by science.

There are multiple compounds, in addition to azadirachtin, found in pesticides that consumers do not want to be inhaling, regardless of their levels of toxicity. This extensive list of California’s banned pesticides features many of them.

Can Cannabis Really Be Pesticide-Free?

High-quality cannabis is free of insects, mold, and mildew. If “clean cannabis” producers are using absolutely no substances to prevent these from attacking your cannabis, how exactly are growers keeping them away from your beautiful buds?

The answers are simple:

  • Growing in a controlled environment, i.e., indoors, allows a producer to regulate what’s going on in their grow rooms, though this definitely heightens the risk of crop loss if pests do enter the room.
  • The law doesn’t always require the disclosure of using approved pesticides. “Just because something is organic or is Clean Green certified doesn’t mean that they don’t use some sort of approved product on the plant,” says Friesen.
  • Applying pesticides during the vegetative state of a plant’s life is a common practice, and pesticides (hopefully) will not remain as the plant begins to flower and produce the final product that ends up on our shelves.

What this all means is that “pesticide-free” is not as simple as it reads, and consumers need to dig deeper into the brands and products that claim it.

Which Pesticides Are Safe for Cannabis?

Though most cannabis producers do implement some sort of pesticide into their growing methods, there are still plenty of safe ways of pest management that will not harm consumers.

Beneficial insects are bugs—such as ladybugs, pirate bugs, and green lacewings—that do not harm cannabis, but instead, eat the pests that will attack it.

In addition to beneficial insects, some growers pull natural pesticides already used in certain plants and apply them to cannabis in order to maintain an organic integrity. Examples of this include rosemary oil and chrysanthemum oil—this is the active ingredient in pyrethrins, common pesticides used on cannabis.

How to Buy Pesticide-Free Cannabis

At the end of the day, the safest cannabis to consume will always be of the pesticide-free variety. The only way we’ll ever truly know what products truly fall under that umbrella is if they go through verified lab testing, and companies provide the results for each and every product.

For consumers seeking that good ol’ clean green, Freisen’s advice is to simply demand it: “Ask for test results and go to shops that actually vet their vendors. Being a consumer is the most powerful position you can be in. And that’s part of the law, they have to disclose that information if they have it.”

And if they don’t have it? Then you don’t want that producer’s cannabis.

'Pesticide' is the most serious buzzword in cannabis right now. However, not all pesticides are meant to be feared. This is why.

How to Tell if Marijuana has Pesticides?

Did you know pesticides can stay in your weed even after harvesting and curing? Thus, before you plant to smoke, it’s a good idea to take some safety measures.

Look at the weed under a magnifying glass, if you spot any white crystalline powder, it’s maybe pesticide residue. An unpleasant and harsh taste in the smoke is also a sign that there may be pesticide residue left on the weed.

This article is to help you understand the factors leading to weed contamination, harms of consuming contaminated weed and how to detect the level and type of contamination.

Is your Marijuana Contaminated?

Cannabis Sativa (hemp) plant is used to make marijuana. It is made by drying the leaves, seeds, leaves, and stems of the hemp. For hundreds of years, humans have been using marijuana for various purposes such as fiber, seeds oil, medical treatment.

Some evidence shows it may be used for severe pain relief, inflammation, nausea, and chronic conditions. It can be consumed mainly by inhalation, oral, sublingual, and topical.

Tetrahydrocannabinol (THC), a component of marijuana, acts on endogenous cannabinoid receptors both centrally and peripherally.

Activation of cannabinoid receptors inhibits parasympathetic activity and inhibits prostaglandin biosynthesis by releasing serotonin and increasing catecholamines.

The decrease in intraocular pressure, analgesia, anti-vomiting (antiemetic) effects and an appetite stimulant are some of the uses of marijuana.

Marijuana is called by different names: Cannabis, Weed, Ganja, Hashish, Hemp, Mary Jane, Pot, Hash, and Reefer. But there comes a question “Is what you consuming is free from contamination.”?

After the Controlled Substances Act was passed in 1970, the perception of marijuana has been changed. Though the federal government still considers marijuana a Schedule I substance, 26 states and the District of Columbia have legalized pot, for recreational use and medicinal use.

To purchase legally, we have to access a professional marijuana retail establishment. It is much safer than purchasing illegally from some unknown dealer.

The vast majority of cannabis users around the world still face problems in buying because of its prohibition. And sometimes this prohibition forces them in buying weed from some not-so-reliable sources.

Many cannabis consumers still buy stuff from the black market as they don’t have any other choice.

However, they don’t think about what they are buying; don’t even think about the contamination factor and they can damage their health by consuming something like that.

Prolonged consumption of this contaminated cannabis can lead to illness and pathologies, which are even worse if not detected.

Never underestimate the presence of contaminants, a potential threat to the health, so it’s important to double-check the quality of your buds before buying and smoking them.

In 2013, the potency of pesticides in legal marijuana at a medicinal dispensary in California is analyzed referring to the study in the Journal of Toxicology.

A potential health concern was brought to the public and is reported in their findings. Chemicals present on cannabis buds are directly transferred into smoke. The study concluded that the high levels of pesticide residue present significant health complications for cannabis smokers.

Handheld glass pipe used by many individuals for smoking can inhale up to 60-69 percent of the chemical residue. Using an unfiltered water piper can expose an individual to 42-59 percent; while using a filtered water pipe can reduce the inhalation to 0.08-10 percent only.

Given these results, pesticide exposure through pots is alarmingly high according to the conclusion given by researchers.

Causes of Weed Contamination

As mentioned earlier, chemicals are one of the reasons behind the contamination. But it is not the only thing behind this. Many other factors are affecting the contamination when held in long-term storage. These are:

1. Bacteria

One of the common contaminants is microbial contamination. Gram-negative bacilli are found in the number of dispensaries belonging to the north of California.

According to the Clinical Microbiology and Infection journal, in the early days of legalization in the states, people had used bad weed. These bacteria get into medicinal cannabis and can cause health problems.

Microbial testing is the only way to find out the level as well as contamination in the weed. Its a good idea to purchase smell-proof herb container. It has in built-in temperature and humidity control that allow you to store your bud at an ideal temperature.

2. Fungus

Grey mold and mildew make the fungal contamination as the number one cause. Your cannabis has been under fungal attack if you can spot a powdery substance or it looks like a fuzzy skin that is greyish.

To grow weed, it is important to maintain ideal temperature and humidity. For this, you can use temperature and humidity sensors.

Chances of fungal infection increases if the room’s temperature and humidity are not matching the ideal conditions.

Hence, it is mandatory to check regularly if any contamination is there, by monitoring the levels using the thermometer and hygrometer.

3. Residual Solvents

CO2 supercritical is used in the extraction and considered as the cleanest method which makes it expensive as well.

To lower down the amount of extraction of cannabinoids, some manufacturers still use butane as a solvent.

The residuals of butane in the removed material can cause serious health problems if remain unchecked.

4. Pesticides

Farmers can face a lot of problems while growing cannabis. One of the biggest problems they face is insects affecting the growth of cannabis. To counter the growth of insects, they use pesticides as a common practice.

This process can save cannabis from the pests but it will affect the end-user with serious health issues. Even though it goes under the harvest and curing process, some pesticides remain in the plant.

It is dangerous to one’s health if inhaled in the presence of these pesticide particles. Most common particles are imidacloprid, spiromesifen, and etoxazole. Use pest control solution like this one.

Contaminants are Further Classified Into

1. Abiotic Contaminants

These are more common in the outdoor plantation than indoor. Contaminants include dust, sand, feathers, hairs, and excess nutrient (mainly nitrogen due to fertilizers).

These microscopic elements inside the consuming buds can cause extreme respiratory irritation such as coughing.

2. Heavy Metals

Many people are unaware of the fact that cannabis, like any other plant, work on the soil they’re grown in. They clean the soil by absorbing everything including nutrients, heavy metals, and other contaminants if any.

Even though being an efficient soil cleaning system, consumption of this weed that is so saturated with heavy metals can be harmful to the human body.

3. Biotic Contaminants

Living organisms contaminating weed are known as biotic contaminants. Extremely common biotic contaminants are insects, viruses, fungi, bacteria, mites, etc.

Referring to the famous case in the 80s in the USA made headlines because of the massive outrage of hepatitis.

An illegal batch of cannabis imported from Mexico is associated with outrage and users who consumed it suffered from hepatitis.

Later discovery revealed that the plants were fertilized using human excreta.

4. Pathogens

Like biotic contaminants, pathogens are also living bodies of bacteria and viruses. Cannabis can be a home of pathogenic bacteria. It is because of humidity maintained for plant growth as these pathogens need a humid environment to colonize and can be transferred to humans if consumed.

Salmonella, one of the deadly bacteria, is most common in this category. It can cause severe fever and symptoms of fatigue that can remit and relapse on a timely basis.

Its diagnosis is quite difficult and hence advised to go for check up if symptoms prevail. If diagnosis not done on time, it can be proved fatal. Other pathogens that can contaminate cannabis are Aspergillus, Escherichia coli (better known as E. Coli) and Spider Mites.


In 1982, marijuana was first linked to the Salmonella infections, published by the New York Times.

The article published stated that- Marijuana smokers were not the only ones who got infected, but children and other people also got infected who lived with them.

Researchers found that, after lab tests were done on marijuana, it had been contaminated by manure, which is possibly used to adulterate.

Apart from all, many dealers to gain profit use various methods to increase the weight eventually contaminating the weed. Contaminants found in this process are residues of sand, glass, and silicon.

Dangers Associated with Smoking Contaminated Weed

Insomnia and headaches are the most common symptoms reported after marijuana consumption according to Marijuana Anonymous. Marijuana may also cause other side effects such as:

  • Depression
  • Lack of concentration
  • Loss of appetite
  • Anger or irritability
  • Dry throat
  • Night sweat
  • Emotional instability
  • Vivid dreams and nightmares

Even after consuming good weed, a person has to go through all these symptoms mentioned above, then you can imagine a person having contaminated weed has to go through even worse emotionally as well physically.

And if medical help is not taken on time, a person can lose his life and sometimes can be paralyzed. One has to keep in mind all the dangers associated with contaminated as well as uncontaminated weed before buying.

A person should not hesitate in seeking any medical advice if he or she has any of the symptoms. Now I am going to address the issues with contaminated marijuana.

Weeds that are given a gritty or sandy texture by adding and stretching it with some kind of foreign substance are referred to as contaminated weed. It is sometimes called lacing.

The cannabis market is facing one of the most significant issues in identifying the level of contamination because of the lack of testing. Most of the time cannabis is safe, but sometimes it is contaminated with harmful substances.

Only a small fraction of weed products are tested for safety before selling to a customer and that too if a person is buying from a legalized store.

Which chemicals are used on the plants by marijuana growers? According to a report from NBC News, fungicide called “myclobutanil” is one common chemical used on weeds. Most often it is used to keep fungi from growing on grapes.

The effects of this fungicide have a relatively low level of toxicity, people who have used or consumed has reported these side effects:

  • Rashes in skin
  • Vomiting
  • Eye irritation
  • Nose bleeding
  • Headache
  • Diarrhea
  • Vomiting

For some people, the presence of this doesn’t persuade them to do something and doesn’t discourage them as well. But it changes to hydrogen cyanide when myclobutanil is heated up.

Inhalation of hydrogen cyanide is incredibly dangerous according to the statement issued by The Organization for the Prohibition of Chemical Weapons. The higher concentration of the chemical can be proved fatal and even smaller amounts can cause many side effects like:

  • Respiratory difficulty
  • Vomiting with blood
  • Unconsciousness
  • Palpitations
  • Convulsions

When contaminations can happen:

  • Seeding
  • Growing
  • Harvesting
  • Drying and curing
  • Extraction
  • Storing
  • Selling

How to Differentiate Contaminated Weed?

1. Unusual Colour

Spotting a discolored weed is much easier. If you can spot a white powdery substance or a fuzzy greenish and grey color, a good chance is that it may have gone under fungus infection due to the presence of mildew and mold.

2. Chest Pain

Heavy smoking can cause unusual and burning sensations that you may feel many a time in your lungs. Although, smoking weed heavily should not make you suffer from these sensations of unusualness and burns.

But, if you are down with uncomfortable chest pain just after smoking cannabis, then you need to see your doctor as soon as possible. This is the side effect of contaminated weed with pesticides and fertilizers.

The condition could be fatal if left untreated, and this can only happen if you’re unaware of grit weeds.

3. Allergies

An itchy throat, eye inflammation or excessive mucus production, then there is a possibility you might have smoked contaminated weed if you haven’t experienced these adverse reactions before after smoking weed.

Going under allergic reaction then it is probably microbial infected or fungus-infected marijuana you have smoked. It is again advised to seek help from a doctor as soon as possible.

4. Scent

Every cannabis is known for its distinct smell – natural and musky sweet aroma and that’s how they are differentiated based on their unique scent.

It is most like to be contaminated and a good chance is has undergone fungus attack if it smells more sweet and damp, or having a ‘gone off’ scent.

The suggestion is to be aware of dried buds that are not cured and dried correctly as per procedures.

These buds carry a smell similar to freshly cut grass. This division of marijuana flowers develops fungus most likely mold when held for storage after extraction.

5. Spongy Appearance

If you have ever touched weed by placing in between your fingers, you might have felt dryness and crisp in it.

This is the sign of uncontaminated weed. What if it is damp and spongy? Then the weed you are going to use is contaminated with mold.

Finally, an altered and contaminated weed can have the following characteristics:

  • Cannabis that looks fine and dry burns irregularly.
  • A chemical smell similar to burnt plastic when you light up the joint.
  • Ash is hard with residues and dark in color, almost black, and it won’t fall off the joint.
  • Weed, when opened up, are much darker from inside than outside and having hard buds that look swollen.
  • Buds that are constantly humid and even impossible to dry by leaving them out, show the presence of some chemical additives.
  • If you notice little bit hard bits even after biting a piece of bud softly, then it’s most likely to be contaminated with sand or glass. Not even a single cannabis plant produces this type of residue.

Remedies One can Seek After Consuming Contaminated Weed

A person has to undergo medical advice and has to seek the help of a doctor, whenever any of the side effects occur in the body as soon as possible.

But in case, it’s difficult to reach the doctor, one can use the following remedies as first aid. These remedies are just to delay the extreme health issues:

  • Drink plenty of water
  • Take a warm bath and cold bath alternatively
  • Reduce the amount of fat from your food
  • Exercise usually anaerobic
  • Reduce or eliminate caffeine consumption


It’s easy to imagine, how dangerous it can be to the health of a person who consumes contaminated weed.

Dangers associated with it can be equally dangerous for short term as well as long term health as it depends on various factors such as person’s body type, how much weed he (she) has consumed, the potency of marijuana, and how long it will stay in one’s body.

A person has to wait longer before their system clears the contaminants’ traces if he or she is a heavy user. They have to go through a more difficult detox process if contaminants traces are more in the body.

How your body reacts to contaminants is determined by the amount of toxin you’re exposed to. Our body works naturally to eliminate toxic substances, but even this natural process has limits.

This is how our metabolic system works. The lower amount of contaminants will probably not affect us significantly but if we have taken a high dose of contaminated weed then we may get exposed to a high volume of contaminants and we can get sick.

With all the information given above, you should buy from legal dealers and use it for medicinal purposes. A person should only purchase the stuff from lawfully operating dispensaries such as Registered Marijuana Dispensaries (RMDs) to reduce the risk of exposure to harmful contaminants.

In some cases, if you’re planning to buy it illegally, double-check it before you consume it as it can have negative impacts on your health if contaminated.

Did you know pesticides can stay in your weed even after harvesting and curing? Thus, before you plant to smoke, it's a good idea to…