Across the US, farm and agribusiness infrastructure largely prioritizes
repairs, expansions, and replacements rather than demolitions with new builds. This is
to be expected, as rebuilding property is expensive and results in operational downtime,
but it can create challenges when older facilities are compared with today's safety
expectations.
Over the past few decades, safety standards have changed dramatically with
continuous investment in researching safe operational practices and loss mitigation
strategies. In fact, the National Fire Protection Agency (NFPA) regularly updates its
standards based on new data, technology, and industry expertise. Rebuilding a facility
every time a standard evolves is not practical, but staying up to date on best practices
and implementing upgrades where feasible is.
For example, the NFPA 70 is the National Electrical Code (NEC) that provides
requirements for the installation of electrical wiring and equipment in commercial and
industrial buildings, and it was created to reduce hazards that result in electrical
shock, fires, or even explosions. NFPA 70B is just as critical and outlines requirements
for inspecting, testing, and servicing electrical systems to prevent failures, reduce
fire and arc-flash risks, and ensure worker safety; electrical malfunctions are among
the leading causes of electrical fires, which can result in thousands of dollars in
losses.
In the most recent NFPA Conference & Expo, there was a strong emphasis on the importance of
the NFPA 70 and accurately classifying hazardous locations to ensure that the proper
code is followed. These standards are always important, but the risks intensify when
combustible dust is on the premises, such as in grain elevators, grain bins, feed mills,
etc. In these environments, an electrical fire can escalate an already costly claim into
a total loss (or even one that claims lives).
Fortunately, these risks don't exist in isolation because NFPA standards are
designed to work together: A dust hazard analysis (DHA) identifies where hazards exist,
NFPA 499 helps classify those hazardous locations, and NFPA 70 establishes the
electrical requirements needed to operate safely within them.
Risk Mitigation Steps
Risk mitigation generally follows four steps.
Perform a DHA, and adhere to NFPA 660 in accordance with the associated
exposures.
Determine whether hazardous locations exist, and classify them using NEC definitions and NFPA 499 guidance.
Apply the appropriate NFPA 70 electrical requirements for those locations.
Regularly inspect, maintain, and test electrical systems to NFPA 70B standards.
DHA
A DHA is a systematic engineering evaluation used to classify and identify
dust hazards within an operation, evaluate associated risks, and determine
appropriate fire safety controls to reduce the risk to an acceptable level. A
DHA is essentially a detailed road map for operations to implement detailed
controls to help protect employees, preserve assets, improve operational
reliability, and reduce financial hardship in the event of an incident. It will
provide various standards or local codes that are referenced and the necessary
equipment (i.e., dust collection systems and explosion protection systems)
for a particular operation based on the dust particle
classification.
NFPA 499
The NFPA 499 is used to evaluate
and classify hazardous locations so the appropriate electrical equipment can be
determined. It is an important tool in conducting the DHA, and they work
together to manage combustible dust risks.
Class II locations. These contain the
presence of combustible dust that is finely pulverized material, suspended
in the atmosphere, and can cause powerful explosions. Typical Class II
locations in agribusiness include the following.
Grain elevators
Flour and feed mills
Plants that manufacture, use, or store magnesium
or aluminum powders
Producers of plastics, medicines, and
fireworks
Spice-grinding plants, sugar plants, and cocoa
plants
Class III locations. Class III hazardous
locations are areas where there are easily ignitable fibers or flyings
present due to the types of materials being handled, stored, or processed.
The fibers and flyings are not likely to be suspended in the air but can
collect around machinery or on lighting fixtures and where heat, a spark, or
hot metal can ignite them. Typical Class III locations in agribusiness
include the following.
Textile mills
Cotton gins
Cotton seed mills and flax processing
plants
Plants that shape, pulverize, or cut wood and
create sawdust or flyings
In Class II and Class III areas, the following are common electrical ignition
sources.
Arc and sparks. Faulty or deteriorated
wiring, loose connections, and standard nonrated switches create electrical
arcs.
Surface temperature overheating. Unrated
or poorly maintained equipment, which are mostly motors and control panels,
that exceed the ignition point of accumulated layers of dust.
Static electricity discharges. Unbounded
or ungrounded equipment and pneumatic conveyors that accumulate
electrostatic charges, resulting in prime ignition sources for dust
clouds.
These ignition sources are well documented in NFPA standards, and they are
conditions that I regularly encounter during my inspections of older facilities
across the nation. It is also common to find electrical rooms in close proximity
to the chambers that generate combustible materials. For example, in grain
elevators and feed mills, a motor control center room or circuit breakers with
outdated panels and/or components are sometimes directly situated next to
milling equipment accumulating dust or with exposed energized components covered
in dust. As shown in the photo below, this is an extremely risky situation.
Source: ARU, used with permission.
Source: ARU, used with permission.
These facilities cannot be expected to rebuild completely with new equipment,
but they must prioritize NFPA-recommended safety measures to reduce the risk of
catastrophic loss. By classifying the locations, the NFPA 499 provides the
information necessary to apply the NFPA 70 and select equipment suitable for the
environment. The Occupational Safety and Health
Administration (OSHA) Standard 1926.407 Hazardous (classified)
locations is utilized in conjunction with the NFPA 499 as a consensus
technical road map to determine the appropriate electrical system design and
zone boundaries.
NFPA 70
After hazardous locations are classified, you can utilize the NFPA 70 to determine how an electrical system should be designed to prevent ignition.
Selecting electrical equipment approved for the classified location
Proper wiring methods and conduit systems
Electrical enclosures that prevent dust intrusion
Grounding and bonding to reduce static electricity
Motors, disconnects, switches, and lighting fixtures suitable for hazardous environments
Overcurrent protection and electrical fault protection
Installation practices that minimize the risk of electrical arcs and excessive surface temperatures
While these requirements apply to all classified locations, some operations
are particularly challenging due to the amount of combustible materials
generated. For example, cotton gins are generally considered agricultural
processing rather than general commercial or industrial manufacturing, thus
typically falling under more lax building and fire code requirements.
I've conducted numerous fire safety inspections on these operations over my
career, and it's all too common to observe exposed electrical wiring, missing
electrical panel covers with fiber accumulation on energized components, or an
unqualified individual repairing faulty electrical equipment, as demonstrated in
the photos below.
Source: ARU, used with permission.
Source: ARU, used with permission.
The NFPA 70 is over 1,000 pages long and far more detailed than the average
agribusiness operator can independently navigate. When assessing or modifying
current electrical systems, owners should only work with qualified,
state-certified electricians or electrical engineers (who are more costly).
OSHA defines standards for
individuals who are competent and qualified to work on these advanced and
sometimes aged systems. A typical handyman (or even an electrician who isn't
specifically trained for these types of facilities) could seriously injure
themselves or pose a serious safety hazard to the entire operation while
attempting to repair or update these systems.
NFPA 70B
Once combustible dust is identified, hazardous locations are classified, and
electrical equipment meets standards, the NFPA 70B outlines rules for
equipment maintenance. According to Eaton, a global leader in
electrical power management, the NFPA 70B "outlines how electrical systems
should be inspected, tested, and serviced to maintain a safe condition. The
standard defines what a documented electrical maintenance program must include
and reinforces the connection between equipment maintenance, worker protection,
and system reliability."
In any operation, electrical equipment is rarely "set it and forget it." As
you continue to use equipment, connections loosen, dust accumulates, components
wear out, and equipment requires maintenance. Regular inspections, preventive
maintenance, and repairs can help identify issues before they become ignition
sources or costly failures. Codes and best practices are constantly evolving,
and ensuring your facility complies with modern safety regulations is
essential.
Conclusion
Many grain elevators, feed mills, cotton gins, and other
agricultural facilities will continue operating for decades to come, and standards
will certainly evolve during that time. Rebuilding these facilities from the ground
up with each refinement of modern construction is not realistic. This is why
adherence to NFPA standards is fundamental to preventing fires, deflagrations, and
explosions in facilities where combustible dust, flammable materials, or combustible
fibers are present.
The guidance outlined in the NFPA 660, NFPA 499, NFPA 70, and NFPA
70B protects personnel, property, and business operations, and failure to comply
significantly increases the likelihood of a catastrophic incident that can result in
financial consequences, reputational damage, or—even worse—loss of life. Compliance
with these standards must be regarded as an integral component of an organization's
business operations.
Opinions expressed in Expert Commentary articles are those of the author and are not necessarily held by the author's employer or IRMI. Expert Commentary articles and other IRMI Online content do not purport to provide legal, accounting, or other professional advice or opinion. If such advice is needed, consult with your attorney, accountant, or other qualified adviser.
Across the US, farm and agribusiness infrastructure largely prioritizes repairs, expansions, and replacements rather than demolitions with new builds. This is to be expected, as rebuilding property is expensive and results in operational downtime, but it can create challenges when older facilities are compared with today's safety expectations.
Over the past few decades, safety standards have changed dramatically with continuous investment in researching safe operational practices and loss mitigation strategies. In fact, the National Fire Protection Agency (NFPA) regularly updates its standards based on new data, technology, and industry expertise. Rebuilding a facility every time a standard evolves is not practical, but staying up to date on best practices and implementing upgrades where feasible is.
For example, the NFPA 70 is the National Electrical Code (NEC) that provides requirements for the installation of electrical wiring and equipment in commercial and industrial buildings, and it was created to reduce hazards that result in electrical shock, fires, or even explosions. NFPA 70B is just as critical and outlines requirements for inspecting, testing, and servicing electrical systems to prevent failures, reduce fire and arc-flash risks, and ensure worker safety; electrical malfunctions are among the leading causes of electrical fires, which can result in thousands of dollars in losses.
In the most recent NFPA Conference & Expo, there was a strong emphasis on the importance of the NFPA 70 and accurately classifying hazardous locations to ensure that the proper code is followed. These standards are always important, but the risks intensify when combustible dust is on the premises, such as in grain elevators, grain bins, feed mills, etc. In these environments, an electrical fire can escalate an already costly claim into a total loss (or even one that claims lives).
Fortunately, these risks don't exist in isolation because NFPA standards are designed to work together: A dust hazard analysis (DHA) identifies where hazards exist, NFPA 499 helps classify those hazardous locations, and NFPA 70 establishes the electrical requirements needed to operate safely within them.
Risk Mitigation Steps
Risk mitigation generally follows four steps.
DHA
A DHA is a systematic engineering evaluation used to classify and identify dust hazards within an operation, evaluate associated risks, and determine appropriate fire safety controls to reduce the risk to an acceptable level. A DHA is essentially a detailed road map for operations to implement detailed controls to help protect employees, preserve assets, improve operational reliability, and reduce financial hardship in the event of an incident. It will provide various standards or local codes that are referenced and the necessary equipment (i.e., dust collection systems and explosion protection systems) for a particular operation based on the dust particle classification.
NFPA 499
The NFPA 499 is used to evaluate and classify hazardous locations so the appropriate electrical equipment can be determined. It is an important tool in conducting the DHA, and they work together to manage combustible dust risks.
This requires an evaluation of the material involved, how it's handled, where dust may accumulate, and the frequency of hazardous conditions. The NFPA 499 helps map out how far a hazardous dust cloud zone extends from a process or collection point, then groups combustible dusts (Groups E, F, and G) based on conductivity and ignition temperature.
The following are classifications of locations.
In Class II and Class III areas, the following are common electrical ignition sources.
These ignition sources are well documented in NFPA standards, and they are conditions that I regularly encounter during my inspections of older facilities across the nation. It is also common to find electrical rooms in close proximity to the chambers that generate combustible materials. For example, in grain elevators and feed mills, a motor control center room or circuit breakers with outdated panels and/or components are sometimes directly situated next to milling equipment accumulating dust or with exposed energized components covered in dust. As shown in the photo below, this is an extremely risky situation.
Source: ARU, used with permission.
Source: ARU, used with permission.
These facilities cannot be expected to rebuild completely with new equipment, but they must prioritize NFPA-recommended safety measures to reduce the risk of catastrophic loss. By classifying the locations, the NFPA 499 provides the information necessary to apply the NFPA 70 and select equipment suitable for the environment. The Occupational Safety and Health Administration (OSHA) Standard 1926.407 Hazardous (classified) locations is utilized in conjunction with the NFPA 499 as a consensus technical road map to determine the appropriate electrical system design and zone boundaries.
NFPA 70
After hazardous locations are classified, you can utilize the NFPA 70 to determine how an electrical system should be designed to prevent ignition.
The NFPA 70 covers the following.
While these requirements apply to all classified locations, some operations are particularly challenging due to the amount of combustible materials generated. For example, cotton gins are generally considered agricultural processing rather than general commercial or industrial manufacturing, thus typically falling under more lax building and fire code requirements.
I've conducted numerous fire safety inspections on these operations over my career, and it's all too common to observe exposed electrical wiring, missing electrical panel covers with fiber accumulation on energized components, or an unqualified individual repairing faulty electrical equipment, as demonstrated in the photos below.
Source: ARU, used with permission.
Source: ARU, used with permission.
The NFPA 70 is over 1,000 pages long and far more detailed than the average agribusiness operator can independently navigate. When assessing or modifying current electrical systems, owners should only work with qualified, state-certified electricians or electrical engineers (who are more costly). OSHA defines standards for individuals who are competent and qualified to work on these advanced and sometimes aged systems. A typical handyman (or even an electrician who isn't specifically trained for these types of facilities) could seriously injure themselves or pose a serious safety hazard to the entire operation while attempting to repair or update these systems.
NFPA 70B
Once combustible dust is identified, hazardous locations are classified, and electrical equipment meets standards, the NFPA 70B outlines rules for equipment maintenance. According to Eaton, a global leader in electrical power management, the NFPA 70B "outlines how electrical systems should be inspected, tested, and serviced to maintain a safe condition. The standard defines what a documented electrical maintenance program must include and reinforces the connection between equipment maintenance, worker protection, and system reliability."
In any operation, electrical equipment is rarely "set it and forget it." As you continue to use equipment, connections loosen, dust accumulates, components wear out, and equipment requires maintenance. Regular inspections, preventive maintenance, and repairs can help identify issues before they become ignition sources or costly failures. Codes and best practices are constantly evolving, and ensuring your facility complies with modern safety regulations is essential.
Conclusion
Many grain elevators, feed mills, cotton gins, and other agricultural facilities will continue operating for decades to come, and standards will certainly evolve during that time. Rebuilding these facilities from the ground up with each refinement of modern construction is not realistic. This is why adherence to NFPA standards is fundamental to preventing fires, deflagrations, and explosions in facilities where combustible dust, flammable materials, or combustible fibers are present.
The guidance outlined in the NFPA 660, NFPA 499, NFPA 70, and NFPA 70B protects personnel, property, and business operations, and failure to comply significantly increases the likelihood of a catastrophic incident that can result in financial consequences, reputational damage, or—even worse—loss of life. Compliance with these standards must be regarded as an integral component of an organization's business operations.
Opinions expressed in Expert Commentary articles are those of the author and are not necessarily held by the author's employer or IRMI. Expert Commentary articles and other IRMI Online content do not purport to provide legal, accounting, or other professional advice or opinion. If such advice is needed, consult with your attorney, accountant, or other qualified adviser.