Recent articles in newspapers, television and the Internet about the detection of pesticides in marijuana is making the “news in the backyards, dinner tables and water coolers chats at work.”

Certainly Colorado and Oregon have made the most news recently about pesticides use on marijuana. The first obvious question, “Why would anyone use pesticides inappropriately on a material that is to be used in a product that is obviously for human consumption?”

Here are pesticide definitions and references from Wikipedia (and the cited references they had in article):

Pesticides are substances meant for attracting, seducing, and then destroying, or mitigating any pest. They are a class of biocide. The most common use of pesticides is as plant protection products (also known as crop protection products), which in general protect plants from damaging influences such as weeds, plant diseases or insects.

This use of pesticides is so common that the term pesticide is often treated as synonymous with plant protection product, although it is in fact a broader term, as pesticides are also used for non-agricultural purposes. The term pesticide includes all of the following: herbicide, insecticide, insect growth regulator, nematicide, termiticide, molluscicide, piscicide, avicide, rodenticide, predacide, bactericide, insect repellent, animal repellent, antimicrobial, fungicide, disinfectant (antimicrobial), and sanitizer.

In general, a pesticide is a chemical or biological agent (such as a virus, bacterium, antimicrobial, or disinfectant) that deters, incapacitates, kills, or otherwise discourages pests. Target pests can include insects, plant pathogens, weeds, mollusks, birds, mammals, fish, nematodes (roundworms), and microbes that destroy property, cause nuisance, or spread disease, or are disease vectors.

Although pesticides have benefits, some also have drawbacks, such as potential toxicity to humans and other species. According to the Stockholm Convention on Persistent Organic Pollutants, 9 of the 12 most dangerous and persistent organic chemicals are organochlorine pesticides.

But, back to extraction – which got dragged into this controversy as a “person of interest” —

Extraction and sample concentration are critical parts of the EPA and USDA protocols. As the analytical instrumentation to detect (qualitative analysis) and tell how much is in sample (quantitate) becomes more and more sensitive, so do the standards that are being developed worldwide. This is referred to as “chasing zero.”

When you place a plant (or soil or water for that matter) into a vessel and then either collect that material that passes through passing gallons of water, or concentrating from kilograms to micrograms of material you will be able to get a more accurate and result from a statistically relevant amount of material. That is why supercritical fluid extraction is used to detect trace levels of pesticides from the soil or plant products.

So to understand that is the way to detect pesticides, it would therefore not be too hard to understand that if you extract 2,000 grams of cannabis into 200 grams of extracted oil that you would also be extracting trace amounts of pesticides or mycotoxins by at least 10 times the amount.

Work in this field has been known for over two decades. This is not a new phenomenon, even back in 1997 Steven Lehotay had authored a review article on the extraction of pesticides from supercritical fluid extraction with CO2.  This article summarizes research findings involving the supercritical fluid extraction (SFE) of pesticides in food and other tissue matrices. Emphasis is placed on multiresidue analysis of pesticides in nonfatty foods, including some previously unpublished aspects of SFE in this application. Brief overviews of pesticides and traditional multi-residue methods are given, followed by discussion of results for SFE applications in the pesticide residue analysis of foods.

Additionally remembering that when using products in traditional manner of smoking that is really an extraction method that was well documented by Dr. Jeffrey Raber, et. al. in which it was stated,

It should be noted that different levels of pesticides present on different varietals of cannabis flowers present different matrixes that may impact the amount of pesticides potentially being inhaled. Different user behaviors including depth of breath, length of inhalation hold time, and choice of heating method may also impact overall individual exposure amounts”.

It is important that as the commercialization of cannabis is moving forward, that people understand that the material they are providing does not have pesticides or other compounds like mycotoxins in them that will be concentrated and expose animals that are already immuno-compromised by disease or healthy animals that would be in the future in danger of the long-term exposure to these compounds.