When designing cultivation facilities or other business types, the design process typically starts with first choosing a property, then choosing a building, and then designing the equipment and systems to outfit the building. When it comes to hemp extraction, we actually recommend the opposite: start with choosing your processing method, then design your facility and systems, and finally choose a property that will work for the building you have designed. 

Hemp extraction typically involves the use of hazardous materials, which can affect a number of building and property codes and regulations. In addition, the type and quantity of hazardous materials can make a big difference in facility design and considerations, such as where materials will be located. If you choose your building and/or property before you’ve defined which extraction method you’ll be using, you may find yourself in a position where the building and/or property you’ve purchased or leased won’t actually work for your facility – which is a major setback for both your schedule and your budget. 

Open vs. Closed Systems

As discussed in Step Two, Part One, determining whether or not your systems are open or closed will have a major impact on facility design, especially when it comes to hazardous occupancy classification. Some of the most important takeaways to remember:

• Open systems are generally more dangerous than closed systems, and will usually trigger a hazardous occupancy classification sooner in the process.
• Code officials have the authority to interpret codes and definitions differently.
• A piece of extraction equipment may be classified as a closed process, but that doesn’t necessarily mean the entire system is a closed system. 
• Equipment manufacturers are not always explicit in their verbiage, so don’t just take their word for it.
• An experienced design team can help you navigate the process and avoid common pitfalls and complications.

Potential H (High Hazard) Occupancy

Building classification is a fairly simple process, but hazardous materials are handled differently from the rest of the code and are generally much more complicated. One of the most important things to remember is that – in the eyes of regulators – your facility is considered hazardous use until you prove otherwise. However, there are many different ways to prove that you aren’t a high hazard occupancy. An F-1 occupancy classification is much easier to deal with, as H occupancy leads to many more requirements and potential limitations. It is extremely important to know if your facility is H occupancy and understand the implications of this classification before you pick a building or site for your facility. 

It is important to define your path early on in the process and decide if you want your extraction operation to stay an F-1 occupancy facility or become an H occupancy facility. There are benefits to each option. F-1 occupancy facilities have fewer safety requirements and limitations, but must adhere to maximum allowable quantity and control room regulations. H occupancy facilities definitely involve a more complex and involved process, but remove maximum allowable quantity and control room requirements, which can be a benefit for operations with larger production goals (and therefore larger amounts of hazardous materials on hand). It can also be more difficult to have additional business uses on the same property as an H occupancy facility.

Whichever path you choose will greatly impact the rest of your facility design. 

Calculating Hazardous Material Quantities 

When it comes to hazardous materials, the main goal is to ensure you are storing and using the materials in compliance with the National Fire Protection Association (NFPA), International Fire Code (IFC), and International Building Code (IBC). Extraction equipment and processes that use hazardous materials must be included in your submittal documents, along with hazardous material quantities and storage methods. The presence and quantity of materials on hand that pose a safety hazard will impact your construction requirements and hazardous occupancy classification. Different hazardous materials will have different maximum allowable quantities, and may also trigger certain safety requirements like ventilation rates or fire sprinkler systems. 

It is also important to understand into what category your utilized hazardous materials fall. The IFC and IBC typically consider hazardous materials to fall into two main categories: physical hazards (explosivity or flammability) or health hazards (toxicity or corrosiveness.) Each category will have different safety implications when it comes to the design and construction of your facility. After all hazardous materials have been classified and quantified, you will need to determine the maximum allowable quantity that is allowed to be on hand at one facility. 

Maximum Allowable Quantities 

Understanding the hazardous materials your business will use and their specific maximum allowable quantities (MAQs) is the first – and probably most important – step in the process. Different types of materials have different MAQs, and using or storing hazardous materials in amounts greater than their MAQ will result in additional safety measures or hazardous occupancy classification. 

Regulators consider how you are using each hazardous material (whether the material is being stored on site or being used in an open or closed system) to determine the MAQ for your facility. Generally speaking, MAQs are higher for materials that are only being stored, and most restrictive for materials used in open systems because they pose the biggest risk to your building and your employees. In some cases, MAQs can be increased by adding additional safety features into your facility, like sprinkler systems or storage facilities. 

The determination between an F-1 and H occupancy facility is entirely driven by MAQs. It is important to note that if your facility is an H occupancy, MAQs do not apply. 

Control Areas

Control areas are directly related to hazardous material MAQs in your facility, and it is again important to note that H occupancy facilities will not have to deal with control areas. Control areas can be used to increase the allowed MAQ of a material without leading to hazardous occupancy classification. A control area is typically a separate interior or exterior room with special safety features to prevent complications due to hazardous materials – think fire-resistant construction, fire sprinkler systems, continuous ventilation systems, or emergency power and alarms. Your building could potentially have multiple control areas depending on size and other factors. 

Enlisting the help of a code expert (architect, engineer, planning consultant, etc.) early on in the process will be helpful to navigate the hazard classifications and associated design and construction considerations associated with your business. Because the usage and storage of hazardous materials can greatly affect the design and construction of your facility, it is important to both your business success and budget to understand this information and the specific associated requirements prior to purchasing land or property.

Once you have a comprehensive understanding of your extraction method, the hazardous materials involved, and the implications on your facility design and construction process, you are ready to start looking for a property that will work for the building you and your team have designed. Stay tuned for Step Three in the series, where we will dive into the important considerations involved in choosing your property. 

About the Co-Author

Stacey Stemach, is the owner of Stemach Design & Architecture. Stacey has nearly twenty years of experience as an architect, spanning an enormous range of project types and complexities. He is innately familiar with renovation work, urban in-fill projects, mixed-use buildings, large industrial sites and multi-family housing. Stacey’s understanding of building codes has enabled the firm to successfully guide complex projects through permitting reviews across several states. His creativity stems from an intuitive sense of how people interact with their built environment.

In Case You Missed It

Getting Started in Hemp Extraction: Step Two, Part One: Choose & Design Facility