Pesticide Testing: Why and What to Test For

In this post:

  • What are pesticides?
  • Dangers of residual pesticides
  • How they occur in cannabis
  • How to prevent it
  • Pesticide testing compliance
  • Pesticide testing methods

What are Pesticides?

A pesticide is any substance that can prevent, destroy, or repel insects, rodents, fungi, weeds, or other forms of plant or animal life or viruses. A pesticide may also be any substance that you use to regulate plant growth, such as a leaf-removing or drying agent. Farmers commonly use pesticides to prevent pests from destroying crops, and the practice is completely legal.

In fact the United States Environmental Protection Agency (U.S. EPA) has a long list of acceptable pesticide ingredients, which it has determined is safe at low levels. Cannabis is no exception to the agricultural rule. While many consumers wish the crop could be regulated according to organic growth standards, several states, including Florida agree that a selection of natural and synthetic pesticides are safe for human consumption.

But pesticides are not without risk, especially at high residual levels. Additionally, not all pesticides are created equal or acceptable for use depending on the state you’re in. At ACS, we test hemp, cannabis and CBD for 61 different pesticides so you know exactly what residues may be left in your oil, extract, tincture, or flower.

We want you to be sure that your plant or product is compliant and safe for your customer.

The Dangers of Residual Pesticides

How Much Residue remains in Cannabis Smoke?

A 2013 study published in the Journal of Toxicology, found that up to 69.5% of pesticide residues, can remain in smoked marijuana. The study investigated three common pesticides, bifenthrin, diazinon, and permethrin, along with the plant growth regulator paclobutrazol using Gas Chromatography-Mass Spectrometry (GC-MS). The study also showed that filtering the smoke through cotton (as is done in cigarettes) can significantly reduce pesticide levels from nearly 70% to 1-11%.

But cannabis smoking devices don’t often include filtration materials, meaning that your customer is at a greater risk of ingesting a detrimental amount of pesticide residue. The findings suggested that the potential threat of pesticides to your customers' health is substantial, especially without adequate quality testing for residual pesticides. Another concern is the use of synthetic herbicides (weedkillers) and soil fumigants (pesticides) prior to harvesting cannabis.

Although regulators may not consider these chemicals as risky--because they’re not applied directly to the plant--herbicides and fumigants in the soil can still infiltrate your cannabis. Herbicide can also contaminate your, wildlife, and workers who are in close contact with the soil.

What are the Health Risks?

According to an article written by Pesticides and You Journal, one common pesticide used in cannabis cultivation is synthetic piperonyl butoxide. (PBO) is considered safe by the EPA and accepted in most states, but it is not without risks. According to the Journal, PBO has been linked to numerous human health dangers, including cancer, neurotoxicity, and liver disease.

While synthetic agents may seem more dangerous than natural pesticides, like pyrethrins, which come from chrysanthemum flowers, natural pesticides are not without risks. According to the Pesticides and You Journal, products containing pyrethrins and metals can also be dangerous for workers and wildlife. According to the Agency for Toxic Substances & Disease Registry, pyrethrin exposure can interfere with nerve and brain function causing symptoms that range from skin numbness, convulsions, to cancer, depending on the level of exposure.

How Residual Pesticides Occur

Pesticides are antimicrobials, disinfectants, fungicides, herbicides, and insecticides that you may use responsibly to prevent pests from destroying or contaminating your crops. When sprayed or applied properly, pesticides are considered safe by the EPA. In fact, government agencies have conducted lab and animal tests to determine safe levels of human consumption.

But the problem is that we still have very little research related to pesticides in cannabis specifically. Additionally, even if you apply pesticides in accordance with regulations, your final product may end up with more chemicals than intended. Here are a few reasons, according to research by the University of Florida’s Agronomy Department that your final product may test positive for pesticide residue.

  • Your crop may absorb pesticides that were previously applied
  • You may accidentally apply more than the recommended rate
  • You may accidentally apply a pesticide too close to the crop
  • You may experience a drift of a pesticide from another site.

How to Prevent It

According to the University of Florida, you can take the following precautions to reduce the levels of potentially harmful pesticide residues:

  • Follow directions for application rate, timing, and placement
  • Don’t use incompatible mixtures that create pesticide waste
  • Do everything you can to prevent pesticide spills
  • Prevent back siphoning into sources of water during the mixing process
  • Calibrate your equipment accurately
  • Avoid mixing more material than necessary
  • Use pesticides that break down quickly
  • Use formulations that reduce the chances of drift

Pesticide Testing Compliance

In addition to following label instructions for safe pesticide application, you must make sure that the pesticides you choose are approved for use. According to Florida’s Department of Health, any pesticide used in the production of medical marijuana or low-THC cannabis (hemp) must be registered with the Florida Department of Agriculture and Consumer Services or the United States Environmental Protection Agency (U.S. EPA).

These pesticides must be classified as minimum risk and the ingredients in the pesticide must be exempt from tolerance requirements. Florida law also requires that you test your medical marijuana and hemp to ensure there are no residual pesticides.  

Pesticide Testing Methods

At ACS, we offer the most sensitive and comprehensive pesticide screening and confirmation available utilizing Ultra High Performance (HPLC) Liquid Chromatography-Tandem Mass Spectrometry (MS/MS). Traditionally, labs used a protocol called immunoassays to measure chemicals with low molecular weights. This method suffered from several limitations, including inconsistent potency results. On the other hand, UPLC and MS/MS are superior methods for testing that offer excellent sensitivity and throughput.

When MS/MS is coupled with LC, the retention time adds another property that helps us correctly identify the substances, resulting in precise results. This technique is ideal for accurate analysis of pesticides commonly used during cannabis cultivation.

Tests You Can Trust:

In 2019, ACS’s clinical grade, ISO17025 accredited laboratory  received The Emerald Test Award for Pesticide Screening for our excellence in detecting precise levels of pesticide contaminants in cannabis. We take pride in these awards  because we use state-of-the-art technology and always exceed the industry standard requirements. “ACS received 14 Emerald Badges total, the most on the East Coast.

Our in-house team of scientists are continuously developing new methods, procedures and protocols. Our Tampa facility is open and transparent to visitors, so give us a call or schedule a visit today! We’ll talk to you about common pesticide residues, health concerns and the latest state and federal standards.

Need a Test or Have a Question

Call Us at 813-670-9197 or Click to send us a message.