People often ask: What part of the cannabis plant is waste if every part of the plant is used? And it’s a great question… Commercial cannabis comprises five main types of business:

  • Cultivation
  • Manufacturing
  • Distribution
  • Retail
  • Laboratory Testing

You can think of each of these business types as a single stage along the industrialized process of creating consumable cannabis goods.

      1. Cannabis flower, the THC- and CBD-containing part of the cannabis plant, must first be grown or cultivated.
      2. Once the flower is harvested, the valuable chemical components must then be isolated from its organic substrate. This is where the manufacturing business type comes into play, and there are many different ways to extract, concentrate, and distill THC- or CBD-containing oils.
      3. Once a clean, pure oil is obtained, it is then infused into a variety of consumable goods including, but not limited to:- Baked goods
        – Hard candies
        – Gummies
        – Lotion
        – Balms
        – Tinctures
        – Sodas
        – Vape juice
        – Cannabis concentrates (hash, resin, shatter)
        – Chocolates
      4. Finished consumable goods are then labeled, packaged, and shipped by distributors to retail outlets.
      5. However, in order to remain compliant with state rules and regulations, distributors must first submit batch samples of product to a licensed, third-party laboratory for quality control analysis. Upon receiving a passing Certificate of Analysis, the goods are approved for sale to the adult public—the final stage of the process.

Is All Cannabis Waste Hazardous? 

All cannabis waste is regulated by the local and/or state government; however, not all cannabis waste is considered hazardous. For a waste to be considered hazardous, it must exhibit one or more of the four following characteristics:

  • Ignitable
  • Corrosive
  • Toxic
  • Infectious

Consider a few common streams of waste from each business type:

Types of Cultivation Waste

Non-Hazardous

  • Cannabis plant material from routine pruning, trimming, harvest, cloning, propagation, etc. (flower, leaf, stalk, root ball, failed plant [mature, clone, etc.]).
  • Wastewater from outdoor/indoor irrigation, reverse osmosis, etc. with cannabis residuals.
  • Grow medium (soil, rock wool, coco fiber, etc.) with cannabis plant residuals (flower, leaf, stalk, root ball, etc.).

Hazardous 

  • Wastewater from outdoor/indoor irrigation, reverse osmosis, pesticide/fertilizer rinse, etc. with cannabis residuals.
  • Discarded process liquids (pesticides, fertilizers, pH adjusters, sanitizers, etc.).
  • Spent lighting/indoor grow lamps/bulbs (HID, HPS, MH, fluorescent, etc.) with ballasts.

Types of Manufacture Waste

Non-Hazardous

  • Post-extraction cannabis biomass (flower, leaf, trim, shake, etc.) with permissible levels of residual contaminants.
  • Disposable items (gloves, PPE, filters, wipes, containers, utensils, etc.) with cannabis residuals.
  • Discarded or wasted product and/or bulk infused ingredients that have either failed visual quality control (QC) or were contaminated in the ‘kitchen’; scraps or cutouts from manufacturing or from equipment cleanout.
  • Defective, returned, expired, or non-compliant cannabis goods/product (flower, extract, concentrate, solid/liquid edible, tincture, topical, vaporizer, and other consumable items infused with cannabis).
  • Used machine fluids from equipment cleanout (vacuum pump oil, heat transfer fluid, etc.).
  • Defective, returned, expired, or non-compliant disposable cannabis vape pens with internal lithium-ion batteries.

Hazardous 

  • Post-extraction cannabis biomass (flower, leaf, trim, shake, etc.) with solvent residuals.
  • Post-refinement semi-aqueous byproduct (fat, wax, lipid, terpene, distillate, raffinate, etc.) with solvent residuals.
  • Disposable items (gloves, PPE, filters, wipes, containers, utensils, etc.) with cannabis and/or solvent residuals.
  • Used process liquids (organic solvents, chemical reactants, etc.) with trace cannabinoids.

Types of Distribution Waste

Non-Hazardous

  • Defective, returned, expired, or non-compliant cannabis goods/product (flower, extract, concentrate, solid/liquid edible, tincture, topical, vaporizer, and other consumable items infused with cannabis).

Hazardous

  • Defective, returned, expired, or non-compliant disposable cannabis vape pens with internal lithium-ion batteries.

Types of Retail Waste 

Non-Hazardous

  • Defective, returned, expired, or non-compliant cannabis goods/product (flower, extract, concentrate, solid/liquid edible, tincture, topical, vaporizer, and other consumable items infused with cannabis).
  • Retired cannabis good/product shelf displays.

Hazardous

  • Defective, returned, expired, or non-compliant disposable cannabis vape pens with internal lithium-ion batteries.

Types of Laboratory Testing Waste

Non-Hazardous

  • Unused cannabis goods/product sample or specimen remaining after testing.
  • Disposable items (gloves, PPE, filters, wipes, containers, utensils, etc.) with cannabis residuals.
  • Used machine fluids from equipment cleanout (vacuum pump oil, heat transfer fluid, etc.).
  • Biotechnology waste containing pathogens and cannabis goods/product.
  • Defective, returned, expired, or non-compliant disposable cannabis vape pens with internal lithium-ion batteries.

Hazardous 

  • Disposable items (gloves, PPE, filters, wipes, containers, utensils, etc.) with cannabis and/or chemical residuals.
  • Used process liquids (organic solvents, chemical reactants, corrosives, etc.) with cannabis residuals.

How to Manage Cannabis Waste 

It’s critical that the above-mentioned streams of waste are managed in a way that is both compliant and environmentally conscious. Very little research has been done into the ecological impact of cannabis and its chemical constituents. For example, we don’t know THC’s effect on aquatic wildlife as it leaches into our underground rivers and water tables—not to mention the dozens of potential contaminants found in these waste streams, introduced during activities such as pest control, fertilization, volatile extraction, and short path distillation. If uncertain, it is the responsibility of the generator (the person or entity generating the waste) to conduct the approved methods of analytical waste stream testing to properly characterize their waste. Common contaminants found in cannabis-related waste include:

  • Various Pesticides
  • Fertilizers
  • Caustics
  • Corrosives
  • Heavy Metals
  • Terpenes
  • Hydrocarbons
  • Alcohols
  • Ketones
  • Pathogens

The Generator Is Responsible for Characterizing the Waste

The responsibility of correctly characterizing waste falls upon the generator, and no one else. The Department of Toxic Substance Control (DTSC) is the federal agency that oversees industrial waste. Their mission is to protect public health and the environment from harm. If a generator determines their waste to be non-hazardous, the DTSC may want to know how they came to that conclusion. Generators have three different ways to make this determination:

  • Generator knowledge
  • Analytical testing
  • Safety data sheet (SDS) information

If the DTSC does not feel that the generator made a thorough enough effort to properly characterize their waste, they may hold them liable for it. This potentially includes unearthing it from a landfill, cleaning up any contamination as a result of the original disposal and unearthing, and then correctly disposing of it. These costs are likely in addition to a fine imposed by the DTSC for improper disposal. With that said, many generators opt to take the ‘safe route,’ where if there is any uncertainty, they treat it as hazardous waste. As long as the generator is properly licensed to generate hazardous waste (EPA ID Number), reports the hazardous waste (CERS or CUPA), utilizes a registered hazardous waste transporter, and disposes at a permitted treatment storage and disposal facility (DTSC), they should not have to worry about any repercussions from ‘over-characterizing’ their waste. Generators should NOT base their determination on cost. Hazardous waste disposal is generally more expensive than non-hazardous waste disposal, and unfortunately this is sometimes a driving factor in the decision-making process.

A Strict Chain of Custody Must Be Maintained

The DTSC requires a cradle-to-grave chain of custody, from the point of generation to the final resting place, when disposing of hazardous waste. The Bureau of Cannabis Control (BCC) and Manufactured Cannabis Safety Branch (MCSB) require a similar chain of custody when disposing of non-hazardous cannabis waste. When a generator opts to use a landfill as their solid waste facility of choice, that chain-of-custody or direct link always remains because the waste is simply sitting in a hole in the ground. When a generator decides to use a compost, digestion, or transformation (waste-to-energy) facility, it effectively removes that link. The reason is that the waste material is converted into a new material via recycling. Similarly, recycling options are generally more expensive than landfill options, and this is often a driving factor in the decision-making process. It is important to note that there is nothing inherently wrong with landfilling over recycling, as long as the landfill (Class 1, 2, or 3) is approved for that specific waste. However, generators often choose recycling as a more environmentally sustainable method of disposal.

Cannabis Waste Management Should Be a Top Priority

For cannabis businesses, the consequences of improper disposal can be severe. A business may even lose its licensure if it’s determined that waste was improperly handled. Because the specifics of characterizing and managing waste can be so complex, many businesses are investing in professional cannabis waste disposal solutions. By establishing a clearly defined waste management plan overseen by knowledgeable professionals, businesses can focus their time and energy on what they do best while still remaining in full compliance. Every part of the cannabis plant eventually turns into waste, and the most important thing for businesses is ensuring that this waste is properly accounted for.