Cannabis, COVID-19, and Cleanup

The current COVID-19 pandemic has brought the use of disinfectants and cleaners to the forefront of the fight to control the virus. Many of the same products that have been recommended for use against COVID-19 by the EPA and CDC have long been used in the cannabis industry to maintain cleanliness and prevent microorganisms, such as molds, from damaging valuable product. There are many different types of effective cleaning and disinfectant products available in the marketplace, and each comes with its own advantages and disadvantages. It is also important to be aware of the health implications and special handling and use procedures for these products.

Commonly Used Disinfectant Products

The section will highlight the most common disinfectant products that are used in cannabis grow facilities. Important health and personal precaution information is provided for each chemical. If these products are used as described below, they are also effective against the COVID-19 virus on surfaces. As with any chemical product, read and follow all manufacturer’s instructions and safety data sheets for instructions on application, proper ventilation, personal protection equipment (PPE), health concerns, and other precautions. All of the products listed recommend using “adequate ventilation” during application, which means having sufficient mechanical exhaust ventilation or fans that bring in fresh or filtered air into a space. Additionally, it is important to check the expiration date to ensure these products will work effectively.

Bleach/Sodium Hypochlorite Solutions. Diluted bleach/sodium hypochlorite solutions (8.25 percent) can be used as an effective disinfectant/antimicrobial if appropriate for the surface it is being used on. Never mix bleach with ammonia or any other cleanser as dangerous chlorine gas may be produced and could cause serious injury or death. After applying a bleach solution, allow it to remain on the surface for at least 10 minutes before wiping down and rinsing off any residue.

Bleach leaves behind a corrosive residue (particularly on stainless steel surfaces), which must be removed after the 10-minute contact time has elapsed. Since these residues are ionic in nature, wiping with deionized water will be most effective for removal. A final wipe down with a 70 percent isopropyl alcohol (IPA)/30 percent deionized water mixture is recommended to hasten drying of the surfaces.

When working with bleach, avoid contact with eyes, skin, and clothing. Ensure adequate ventilation. Use PPE, including disposable chemical gloves, and eye and face protection. Use respiratory protection if irritation is experienced. A NIOSH-approved respirator equipped with filters designed for chlorine vapors is the most effective. Always wash hands and any contacted skin thoroughly after using.

Hydrogen Peroxide/Peracetic Acid Solutions. There are several commercially available disinfectant/biocide products that contain diluted solutions of less than three percent hydrogen peroxide or a combination of hydrogen peroxide/peracetic acid that have been shown to be very effective against microbials. As with bleach solutions, these products can be very irritating to the skin, eyes, nasal passages, and throats due to vapors emitted during and after application. Use with adequate ventilation, and PPE should include disposable chemical gloves, eye, and face protections. Use respiratory masks if irritation is experienced. A NIOSH-approved respirator equipped with filters designed for acid/organic vapors is the most effective. Wash hands and any contacted skin thoroughly after using.

These solutions fully volatilize, meaning they do not leave a residue as with the use of chlorine bleach and do not require rinsing surfaces after use.

Isopropyl Alcohol (70 percent). IPA is a very effective disinfectant and cleaner. It is very important that a 70 percent IPA concentration is used. IPA is a flammable volatile organic compound (VOC), so it is very important to use with adequate ventilation. Wear eye protection, face protection, protective clothing, and protective gloves. IPA is not as strong an irritant as the previous chemical products described above, but has been reported to have increased effects on the central nervous system. If a respirator is used during IPA use, it should be NIOSH approved and be equipped with an organic vapor filter. Wash hands and any contacted skin thoroughly after using. Similar to the hydrogen peroxide/peracetic acid solutions, IPA will not leave a residue and does not require rinsing surfaces after use.

Quaternary Disinfect Cleaners (Ammonia Solutions). Quaternary ammonia disinfectant products can also be used to clean and disinfect surfaces. As with bleach and hydrogen peroxide/peracetic acid solutions, quaternary ammonia disinfectant products can be very irritating to eyes, respiratory passages, and skin. Only use with adequate ventilation. Wear eye protection, face protection, protective clothing, and protective gloves. If a respirator is used, it should be NIOSH-approved and be equipped with an ammonia vapor filter. Wash skin thoroughly after handling. Be sure to remind your employees to never mix bleach with ammonia or any other cleanser, as dangerous chlorine gas may be produced and could cause serious injury or death.

PPE and Hand Hygiene

The use of PPE during cleaning and disinfecting is necessary for yourself and your employees due to the caustic nature of the chemicals contained in cleaning and disinfecting products.

Verify that employees know to wear disposable gloves for all tasks during the cleaning process when using these solutions. Respirators and goggles maybe required or recommended depending on your choice of solution and chemical, where ventilation is limited, and where vapors may result in irritation or neurological effects, such as dizziness. There are a wide variety of respirator filters, so check the product recommendations or respirator filter product information.

Disposable gowns, where available, could be used to protect clothing from splash contamination or damage during cleaning and disinfecting. Gloves should be compatible with the disinfectant products being used, e.g. some caustic chemicals as some gloves provide only limited protection. Additional PPE, such as rubber boots or eye protection, may be required or recommended based on the cleaning/disinfectant products used and whether there is a risk of splash or inhalation. Gloves, masks, goggles, gowns, and contaminated clothing should be removed carefully afterwards to avoid cross-contamination of the wearer and the surrounding area. Be sure to wash your hands after removing P

IAQ Considerations Post Cleaning/Disinfecting

All of the chemical products previously listed can produce chemical vapors or residues that may cause irritations to the skin and respiratory system, produce central nervous system effects (dizziness, confusion), and may cause severe respiratory and other health symptoms to your employees working directly with the products as well as to employees or customers in the vicinity of those working with these products. This is particularly true in sensitive populations who may have underlying respiratory illnesses such as asthma, allergies, COPD, or cancer. It is important to notify employees and post signage for anyone who may have underlying health conditions or are sensitive to chemicals prior to using cleaning and disinfecting products so they may request protective measures or avoid the area being cleaned and disinfected.

During and after the use of cleaning and disinfecting products, it is recommended whenever possible to increase ventilation in the area of use, or use a fan to direct fresh air into the area. By continued use of ventilation as recommended above, the cleaned and disinfected area should continue to “air out” or dilute the chemical vapors as they continue to volatilize.

Storage of Cleaning & Disinfecting Chemical Products

It is important to remember that cleaning and disinfecting products are chemicals and need to be stored properly. Keep Safety Data Sheets in centralized and accessible area for emergency use. Always refer to the Safety Data Sheets for information on proper storage for each chemical, as storage requirements are different based upon the chemical properties and type of chemical. For example, chlorine bleach should never be stored with ammonia-containing products. Hydrogen peroxide-containing products should never be stored with flammable liquids. The type of container and amount of product may also dictate where you store these chemical products.