How times have changed. Before the early 1980s, hazardous-materials (hazmat) storage buildings were stick-built buildings. They usually were built outside the existing building at the direction of the plant manager and designed by architects and engineers.
Final approval for the structure fell to a local official who reviewed the building or system designs and plans in relation to federal, state and local codes. That person was known as the local authority having jurisdiction (LAHJ). The LAHJ had the authority to allow occupancy and use of a structure or building based on his or her interpretation of the codes.
Hazmat storage buildings have come a long way since then. Pre-engineered buildings designed for the storage, mixing and processing of hazardous chemical, biological and radioactive materials became available in the early 1980s.
Since federal and state legislation began classifying and regulating hazardous chemicals, biological agents and radioactive materials, pre-engineered buildings were developed that allow for better storage methods in well-defined and monitored areas. They come complete with wall, floor (or sump) and ceiling systems to reduce or eliminate the risk of spills, explosions or fires.
Functionally, pre-engineered hazmat buildings fill four important roles: 1, They offer containment for virgin and waste material spills per Environmental Protection Agency (EPA) rules, fire codes or other local requirements; 2, They minimize or contain the effect of fires; 3, They provide a controlled environment for their contents; and 4, They allow for personnel movement within the storage building to allow more functionality than simply storing materials.
The buildings offer a practical solution to many storage needs because they offer a delivery time of eight to 10 weeks vs. six months to a year needed to erect a building on site. They also offer minimal disruption to the existing operations. In some cases, utilizing separate, pre-engineered processing buildings may be the only way to continue production.
Regulations and Requirements
Like any other building, pre-engineered hazmat facilities must meet all applicable federal, state or local codes. They also must meet storage requirements found in EPA regulations such as the Clean Air Act and the Clean Water Act. (For more information about EPA standards, go to www.epa.gov.)
In addition, pre-engineered storage facilities are designed to meet the high-end requirements of the model safety codes. These include model building codes (IBC, BOCA, UBC, SBC), fire codes (IFC, UFC, NFPA), energy codes (ASHRAE 90.1, for example), mechanical codes (IMC, SMC, UMC, NMC), plumbing codes (IPC, SPC, UPC, NPC), handicapped codes (ADA, ANSI Al17.1) and the National Electrical Code (NEC). Because manufacturers use standardized designs and construction techniques meeting the most stringent building requirements for most jurisdictions in the country, many customers receive buildings that are manufactured to exceed local codes.
Many of the codes take into account environmental conditions in the community in which the building is located. For example, buildings for wintry areas must meet a minimum snow load (typically 40 pounds per square foot). Buildings along a shoreline must withstand worst-case wind pressures (typically 110 mph). Buildings generally can withstand earthquake forces from the potential severity of earth movements based on earthquake zones 1 through 4.
Most modern, pre-engineered buildings have passed building standards approved by the states where they're located or been approved by the state's designated third-party agencies (see Sidebar 1). The state's engineers (or their agencies) review the building's features, audit and review the manufacturer's quality control system for manufacturing consistency, and confirm the proper use of listed components from nationally recognized testing laboratories.
Idaho, Washington and Oregon have their own plan reviewers. The other states authorize other third-party agencies (as shown in Sidbar 2) to review and inspect buildings during their manufacture.
Once regulations are met, the "fun" part begins: choosing a building design to suit your needs. Pre-engineered buildings come in many design types and can include a number of optional equipment items.
Most pre-engineered buildings offer access by fork or hand truck. Pre-engineered buildings generally come with one 60-inch-wide double door. This door comprises one active self-closing door for personnel access and egress, and one inactive door to enable access to the building for pallets or totes.
Buildings more than 200 square feet require two exits for safe egress. Often on two-exit buildings, one door has no ramp. The building is loaded using a fork truck, which slides the contents in through the open door. The other door is fitted with a ramp for material access; movement of materials inside the building and final storage is accomplished using a hand truck.
Depending on your needs, you can choose from noncombustible steel buildings, noncombustible fire-rated (two- and four-hour) buildings and explosion-resistant buildings. A building's construction type (i.e., noncombustible or fire-rated for two- or four-hour fire resistance) is based on where the building is located in relation to other buildings that could burn or be burned. Because of the nature of hazardous materials, all units require explosion-proof electrical components.
The temperature, materials and intended use (storage, mixing or dispensing) of the building dictates explosion-resistance requirements. Model building codes require a minimum 50-foot setback from other buildings in the event of an explosion.
Buildings can be equipped with permanent or portable emergency eyewash or shower equipment. In addition, protective clothing and spill cleanup kits should be maintained in the building. Emergency phone numbers of fire, medical, EPA and hazmat cleanup specialists should be accessible.
Hazmat storage buildings can be designed with shelving systems, racks or platforms that increase available storage space. The versatility of these types of structures is enhanced with the addition of worktables, recycling sinks, chemical fume hoods and related equipment, converting a storage space into an area that can be used for dispensing, mixing and postapplication cleanup of hazardous materials or other chemicals.
Pre-engineered hazmat buildings bolster facility security on two levels: They offer security from unauthorized access and provide secure storage of materials so accidental releases do not occur.
To provide security from unauthorized access, these facilities should be solidly constructed and equipped with lockable doors to control access and egress from the building. Door locks must include interior release mechanisms or panic hardware to avoid accidental entrapment. Security nightlights and door alarms should be considered and are good investments.
To ensure the security of the surrounding area and environment, pre-engineered hazmat buildings offer a "secondary containment" sump that contains any potential leakage or spillage of liquid or solid hazardous material. EPA regulations for hazardous waste require the secondary containment capacity to be equal to 10 percent of the total amount stored and be able to contain 100 percent of the contents of the largest container stored. Some local communities have more stringent requirements, reaching up to 30 percent containment of the total amount stored and 150 percent of the largest container stored. Some jurisdictions also require capacity for 20 minutes of fire protection water plus containment of the contents of the single-largest container.
Sump floor and wall construction should be of heavy-gauge, impermeable material that is not easily damaged. For additional protection, sump liners or coatings should be considered to prevent damage to the containment area from exposure to corrosive materials. The secondary containment sump must be easily accessible by lifting the floor decking, allowing for periodic inspection and any cleanup needs. Sump drains, if provided, should be routinely checked because they could become a source of leakage from the containment reservoir if not properly maintained.
Heating, Ventilation and Cooling
Pre-engineered safety storage buildings typically offer interior partitions, sump separation, exhaust fans, air vents, heaters, air conditioners and fire suppression systems to help control chemical storage conditions.
Enclosed spaces should be properly ventilated, by natural or mechanical means, to reduce the concentration of any hazardous vapors and dust present. A minimum of one cubic foot of exhaust ventilation needs to be provided per square foot of storage space (1 cfm/sq. ft.). An adequate number of air intakes should be located within 12 inches of the floor and should be measured from the sump floor surface, not the floor decking above the sump. The air exhaust vents should be located high on an opposite wall.
Where dispensing and mixing operations occur, mechanical ventilation systems are necessary, and local ventilation should be considered. Technically, the storage of any open container in the area will cause the storage area to be considered a dispensing area.
Because many chemicals are temperature-sensitive, heating and cooling systems can extend the shelf life of an existing hazardous materials inventory and allow economical purchases of materials during off-peak seasons. Building insulation is a good investment that will reduce expenditures on annual energy consumption.
It is best to separate certain classes of chemicals logically by the hazards they exhibit. In essence, it is good practice to separate corrosives, oxidizers, caustics, flammable/combustible liquids, water reactives, radioactives, reducers, compressed gases, etc., from one another. Also, within these hazard classification groupings, incompatibilities can exist, with physical separation required. Two good storage recommendations: Separate organic acids from inorganic acids, and don't store chemicals alphabetically, because incompatible materials likely may be stored next to each other.
If the user is not sure as to the best method to ensure compatibility, provide all material safety data sheet information to the LAHJ, building manufacturer or chemical supplier for further guidance, or hire a consultant with hazardous materials expertise.
Hazardous materials always should be stored in their original containers, labeled properly and inspected regularly. In some instances, checking the Department of Transportation (DOT) hazard class label affixed to the outside of the packaging can help to ensure the proper separation of incompatibles. Avoid storing materials with dissimilar labels together. (See additional references for compatibility and storage on this page.)
Fire Protectionand Electrical Systems
Fire protection is an issue that should be reviewed with your local fire department and insurance underwriters. When storing flammable materials, the storage area should be equipped with an automatic fire extinguishing system. Additional fire protection can be obtained by specifying two- or four-hour fire-rated construction, which is chosen based on local building codes and proximity to other buildings, structures and property lines.
Some hazardous materials do not generate enough flammable vapors at normal building temperatures to be concerned with potentially dangerous sparks or heat; however, some do. If explosive or fire conditions are possible, government codes state that electrical components must meet NEC requirements and be listed with a nationally recognized test laboratory. Buildings should be electrically grounded to meet national, state or local codes.
Storage facilities should be accurately marked with DOT and NFPA-704 hazard rating signs that identify the specific hazardous material class being stored and the degree of hazard. Correct designation can be obtained from the chemical manufacturer or distributor. In addition, material warning signs in English, Spanish, French, etc., as applicable, are highly recommended. Copies of the material safety data sheets should be provided to your employees, in addition to training on the proper use and spill cleanup procedures of the chemicals.
The Bottom Line
Pre-engineered buildings offer an economical solution to many hazardous materials storage issues. They usually feature lower costs per square foot than site-erected buildings. Also, they have no associated architectural and engineering fees if they are standard products and few fees if they are special orders. Plus, there are minimal contractor's fees, usually just the cost of a simple pad to support the weight of the building, and they easily can be relocated to meet expansion plans.
Because pre-engineered hazmat buildings meet local, state and federal regulations and include equipment designed to minimize spills, fires and other emergencies, they often times result in the most economical insurance premiums, because damage and loss is confined to one detached, prefabricated building. Also, when anchored properly, such buildings may be considered permanent installations by the LAHJ and result in more favorable insurance premiums.
Finally, the buildings can be viewed as a piece of equipment and depreciated differently for tax reasons. As such, they represent no property improvement and, therefore, are subject to no additional property taxes.
About the author: Paul Graham is president and owner of C&I Consultants, a firm assisting the fire, safety and warning industries. C&I's specialties include the formulation of and changes to national and international codes and standards, marketing and engineering research, and technical and intellectual property training, understanding and deployment. He is a professional engineer in Illinois and can be contacted at [email protected] He would like to thank Ken Wilkins, Roger Quinlan and others at Safety Storage Inc. for their help in writing this article.
States Requiring Approval for Pre-engineered Buildings(1): Arizona, Minnesota (2), California, Missouri, Florida, North Carolina, Georgia, New Jersey (2), Idaho, Ohio, Indiana, Oregon, Iowa, Rhode Island (2), Kentucky (2), South Carolina, Maryland, Texas, Massachusetts and Washington. (1 = Partial listing of states requiring approval for units of closed construction; 2 = Approval through the Industrialized Building Commission)
Third-Party Agencies Authorized to Inspect Pre-engineered Buildings (3)
A.N. Vendola Inc., New Britain, Conn.; Hilborn, Werner, Carter & Associates, Clearwater, Fla.; Modular Code Consultants Inc., Camp Hill, Pa.; NTA, Nappanee, Ind.; PFS, Madison, Wis.; Progressive Engineering, Goshen, Ind.; Pyramid 1 Inc., Goshen, Ind.; RADCO, Long Beach, Calif.; T.R. Arnold & Associates, Elkhart, Ind.; Underwriters Laboratories, Northbrook, Ill.
(3= State verification required)
- Environmental Protection Agency (EPA): www.epa.gov
- Building Officials and Code Administrators (BOCA): www.bocai.org
- National Fire Protection Association (NFPA): www.nfpa.org
- International Code Council (ICC): www.intlcode.org
- International Conference of Building Officials (ICBO): www.icbo.org
- Southern Building Code Congress International Inc. (SBCCI): www.sbcci.org
To order standards:
- Global Engineering Documents: global.ihs.com
For more information about storage buildings, contact Roger Quinlan, national sales manager, Safety Storage Inc., 2301 Bert Drive, Hollister, CA 95023; (800) 344-6539; www.safetystorage.com.