Also known as hot work

Processes used to join or sever materials

May use a variety of energy sources, including a gas flame or an electric arc

Significant cause of fires in commercial and industrial occupancies and on construction sites

Process One

• Uses an electrical arc as a heat source

Process Two

• Uses a combination of oxygen and fuel gas
• Acetylene is commonly used

Both processes generate temperatures in excess of the melting point of the metals

Equipment maintained

Equipment in working order

Equipment stored properly

Combustible materials kept well away from hot work operations

Oxygen and fuel gases in cylinders are stored properly

Gas regulators maintained at their proper settings

Examples: sparks and hot slag, a glass-like residue that the process creates

Verify that sparks or slag cannot come in contact with combustible materials

Combustible materials should not be stored in the welding or cutting areas

Shop rags or towels should be kept in approved metal containers with lids at all times

Inside buildings when automatic sprinkler systems are not in operation

In the presence of explosive atmospheres

On drums, tanks, or other containers that have previously held flammable liquids

Near large quantities of exposed combustible materials

An area with a radius of at least 35 feet (10.7 m) must be cleared

When it is impractical to create this size radius, the materials must be covered with approved fire-resistant guards or curtains

NFPA® 51, Standard for the Design and Installation of Oxygen-Fuel Gas Systems for Welding, Cutting, and Allied Processes

NFPA® 51B, Standard for Fire Prevention During Welding, Cutting, and Other Hot Work

FM Global Loss Prevention Data Sheets

Fire watches

Issuance of permits

Development of hot-work programs

Written plan

Approved by the AHJ

Establishes procedures to prevent fires resulting from temporary operations

Involves operations that use an open flame or produces heat, sparks, or hot slag

Welding

Brazing

Cutting

Grinding

Soldering

Thawing pipes

Applying roofing with a torch

• May also have requirements for as-needed welding and cutting operations
• Should consider annual permits to conduct operations in fixed locations

Local municipal jurisdictions

• Developing the hot-work program
• Establishing a written policy for hot work
• Applying for the permit

Owner/occupant responsibility

• The area where the work is to be performed before a work permit is issued
• Note all hazards in the area
• Discuss emergency procedures with applicant

Inspection

Date

Work to be performed

Period for which the permit is valid

Location of the job

Type of fire suppression equipment available

Inspection of area before work begins

Authorization signature of individual in charge

Notification of when a fire watch is assigned

Final signature of the individual after the work has been completed

Combustible contents are closer than 35 feet (11.7 m) from the point of operation

Adjacent areas having wall or floor openings are within a 35-foot (11.7 m) radius

Exposed combustible materials are in adjacent areas, especially concealed spaces, walls, and floors

Anytime a fire could spread due to conduction or radiation

See NFPA® 1, Fire Code, NFPA® 51b, Standard for Fire Prevention During Welding, Cutting, and Other Hot Work and IFC for other requirements

Use of required fire extinguishers appropriate for the level of hazard

Procedures to warn occupants

Procedures to summon the fire department in the event of a fire

• Primary hazard comes from pressurizing a flammable or combustible liquid and discharging it through a small orifice
• Creates an aerosol
• Easily ignited

Spray finishing

• Involves the suspension of electrically charged combustible powders like polyester resin
• Hazard in this process is flash fire or dust explosion

Powder coating

• Involves the placement of a suspended article into an open dip tank of flammable or combustible liquids
• Constant vapor production as the liquid evaporates increases the risk of fire

Immersion coating

Use of mechanical ventilation

Installation of noncombustible equipment or noncombustible enclosures

Specification of hazardous electrical location boundaries in and around the spray finishing process

Automatic fire extinguishing system in and around the flammable finishing process

Administrative controls limiting fuel amounts/other ignition sources

Interlocks to stop the flammable finishing process if mechanical ventilation is lost or the automatic fire extinguishing system activates

Application of water-based coatings

Use of coatings supplied from disposable aerosol containers

Manual application of flammable liquids over small areas using brushes or rollers

Utilizes compressed air or hydraulic energy to atomize flammable or combustible liquids into small droplets

Hydraulic systems are termed airless spray finishing because it does not utilize compressed air

A noncombustible enclosure constructed of carbon, galvanized, or stainless steel panels with a plenum

Plenum is connected to a noncombustible exhaust duct that discharges outside

Must be designed to maintain the atmosphere inside at an atmosphere less than 25 percent of the lower flammable limit for the most volatile flammable liquid

Generally, acetone is used because of its high evaporation rate

Generally speaking, a conventional spray booth designed for a passenger automobile is designed to exhaust at a rate of 8-11,000 cubic feet/minute

Confirm this air exhaust rate

Mechanical inspectors commonly require an air balance test to confirm the exhaust fan is properly sized and functioning correctly

Test confirms that the system meets the manufacturer’s specified flow rate

Must be designed for hazardous (classified) locations

Interior space of spray rooms or booths is illuminated with electric lamps

Fire codes and NFPA® 33, Standard for Spray Application Using Flammable or Combustible Material, require that these lamps be listed for use in Class I, Division 1 atmosphere, a National Electrical Code® classification

Acceptable methods include automatic sprinkler protection and dry chemical fire extinguishing systems

Another key fire protection feature is the interlock

NFPA® 33, Standard for Spray Application Using Flammable or Combustible Material, and model fire codes require the mechanical ventilation system be interlocked

Powder is ionized with positive electrons so it will adhere to the metal

After coating, the powder is backed to form a durable finish on the material surface

Powder is applied in a ventilated enclosure, which can be a spray booth or a spray room

Primary hazard of powder coating is the ignition of the combustible powder inside the room or space where it is applied

• Verify equipment is listed for combustible powders
• Powdered polyester resin is a combustible resin
• Equipment must be listed for hazardous locations under the jurisdiction’s electrical code

Powder application equipment

• Collector may be part of the booth
• Can be an independent device that is ducted to a dust collector

Powder collection system

• In the spray space
• Booth is constructed using noncombustible materials

Automatic fire extinguishing system

Combustible liquids

• Flammable liquid storage tanks
• Conveyor pumps
• Heaters and heat exchangers
• Agitators
• Ventilation and exhaust equipment

Equipment

Should be located away from other process areas

Never located near an egress area

Dip tanks and reservoirs should be contained in 1-hour fire-rated construction

Ignition sources identified and removed if possible

Production and safety components in place

Use suspended nonflammable curtains to shield an operation

Explosion-venting construction can be used

Ventilation and exhaust of the areas

Housekeeping

Maintenance

Regular inspections

Elevators

Conveyors

Hoists

Cranes

Medium must remain fluid and stable; minerals oils are commonly used

Two types of quenching: heated and unheated

Located in fire-resistive buildings away from the main production areas

Ventilation system

Automatic sprinkler system

Designed where conveyor systems automatically stop in the event of a fire

All portions of the process should be interlocked

• Open flames
• Spark-producing equipment or processes
• Equipment whose exposed surfaces exceed the autoignition temperature of the quenching medium

Eliminate

Enclose hazards

Train workers

Control overflow risk

Should be located at grade level

Should be designed with enough freeboard to keep the tank from overflowing

All tanks should have drains

Should be built within dikes with drains capable of containing the contents of the tank or moving it into specialized holding tanks

Installation of drain boards and automatic-closing covers

Fire extinguishers of several types must be available

The process removes dirt, grease, and stains from clothing or other textiles by using solvents

Classified as a business occupancy

Facilities with onsite cleaning may be classified differently, such as a hazardous occupancy

Presents numerous chemical, fire, and environmental hazards

Presence of all the elements necessary for uncontrolled fires

• Perchlorethylene reduced fire hazards but introduced environmental concerns
• Newer solvents in common use today have fewer environmental concerns but greater flammability hazards

Types

• Dry cleaning plants are classified by the type of solvents used in the process
• Type I plants are prohibited
• Small quantities of Class I solvents may be stored and used in the other classifications of plants

Classifications

• Establish that the fire protection requirements of the locally adopted code are met

Plans review

• Quantity of Class I solvents is limited and properly stored
• Dry cleaning plant type and solvent used match
• Routine maintenance is performed
• All containers with flammable or combustible petroleum-based solvents are properly stored, transported, and used
• A No Smoking policy is in place, enforced, and signs are posted
• Correct size and number of portable fire extinguishers are available
• Personnel trained in extinguisher use
• All fire protection equipment is operational

Inspections

Given the correct mixture of oxygen and an ignition source, a dust hazard in sufficient quantity can create a fire, conflagration, or explosion

A dust explosion can be severe enough to destroy an entire facility

The U.S. Chemical Safety and Hazard Investigation Board (CSB) identified 281 combustible dust incidents between 1980 and 2005

Even materials that do not burn in larger pieces can form combustible or explosive dust

Agriculture

Chemical manufacturing

Pharmaceutical production

Furniture

Textiles

Fossil fuel power generation

Recycling operations

Metal working/processing

Combustible dust must be suspended in air

Particle concentration must be within its explosive range

Ignition source must be present

Dust must be in a confined space

Oxygen content must be capable of supporting combustion

The first explosion usually is not as severe as subsequent explosions

The first explosion stirs dust that has settled on ledges, walls, equipment, or in areas of low travel

The second introduction of particles to the air generally results in larger and stronger explosions

• All-encompassing standard on how to design a safe dust collection system
• Requires that process hazard analysis be conducted for processes handling powders and bulk solids that present a fire or explosion hazard
• Can assist the inspector as a reference when preparing to conduct inspections

NFPA® 654, Standard for the Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids

Locally adopted codes

Particle size (surface area-to-mass ratio)

Moisture content as received and dried

Minimum dust concentration to ignite

Available oxygen in atmosphere

Minimum energy required for ignition

Maximum rate of pressure rise at various concentrations

Minimum dust layer ignition temperature

Maximum explosion pressure at optimum concentration

• Evaluate those operations and tasks where dusts are present or may be generated
• Provide the required safety and handling information to their employees

Basics

• Appropriate engineering controls
• Work practices
• Personal protective equipment
• Include that information on the SDS

Control measures

• Metal dusts including aluminum, magnesium, their commercial alloys, and other dusts whose particle size, abrasiveness and conductivity present hazards in the use of electrical equipment

Group E

• Volatile dusts containing more than 8 percent carbonaceous materials
• Materials include coal, carbon black, charcoal, and coke dusts present in manufacturing and power production facilities

Group F

• Dust atmospheres produced in flour, grain, wood, plastic, and chemical processing operations

Group G

• Combustible dust is in the air under normal operating conditions; in sufficient quantities to produce an explosive or ignitable mixture
• Mechanical failure or abnormal operation of machinery might cause such an ignitable mixture
• Group E combustible dusts are in quantities sufficient to be hazardous
• Dust accumulations are greater than 1/8 inch (3 mm) thick under normal conditions

Class II, Division 1

• Combustible dust is produced due to an abnormal operation; present in quantities to produce explosive or ignitable mixtures
• Dust accumulations have occurred but are normally insufficient to interfere with normal operation of electrical equipment
• Accumulation of combustible dust on or in the vicinity of electrical equipment could lead to its ignition by abnormal operation or failure of the electrical equipment

Class II, Division 2

Passive

• Include providing enclosures for conveyor belts
• Reducing the speeds at which materials are moved through the facility on conveyor belts or through chutes

Active

• Air material separators
• Usually mechanical dust-collection systems capable of collecting 99.5 percent of the dust and storing it in bins outside the facility

Cleaning programs must be performed daily or as needed

Dust continually picked up by manual sweeping, vacuuming, or other means; placed in appropriate storage bins or containers

Metal of all types collected and separated

Electrical equipment in the plant needs to be compliant with NFPA 70®, National Electrical Code and listed for this environment and use

Motors may need to be nonsparking and intrinsically safe

All equipment grounded to minimize static electricity

Smoking restricted to designated areas

Fire protection equipment as required by the locally adopted fire and building codes and the referenced NFPA® standards

• Comply with locally adopted codes
• Building should have fire extinguishers in accordance with NFPA® 10

Basics

• Means of notification for occupants
• Preplanned evacuation assembly area
• Person designated to notify emergency responders
• Facility layout drawings
• Location of safety data sheets (SDSs) or material safety data sheets (MSDSs)
• Emergency telephone number(s)
• Emergency response duties for occupants

Written emergency action plan

Control the dust and the ignition sources

It is important that dust-collecting systems be located outside the grain elevator

Buildings should be built in accordance with the building code used in the jurisdiction as well as NFPA® 61

Life safety issues for a grain-handling facility should comply with the appropriate locally adopted fire and building codes

Belt loaders

Belt discharge or transfer points

Trippers

Turnheads

Distributors

Unfiltered vents

• A machine that turns scrap wood into splinters or chips
• Small pieces of metal, called tramp, wear off the machine during the milling operation; accumulate in the hog trap
• Trap can become hot enough to ignite wood on contact
• Fire can then spread into other portions of the machinery, including the dust collection system
• These fires are often hard to control
• Fires also may be located within an elaborate system of ducts, storage bins, and other associated equipment

Dust hogger

Fine metal dust has an enormous explosive potential

Review the company’s policies on smoking and open flames

No smoking, open flames, electric- or gas-cutting or welding equipment, or spark-producing operations should be allowed

Employers need to enforce strict rules that employees may not carry lighters, matches, and smoking materials

Employees working in a metal dust processing or handling area should wear flame resistant personal protective clothing

Imperative that workers be trained in emergency procedures

Workers need to be familiar with the emergency PPE they must use

Warning signs must be posted for areas containing inert fire protection systems and explosion protection systems

Spark-producing portable power tools and propellant-actuated tools should not be used where combustible dust is present

All equipment, floors, and walls must be carefully cleaned; all dust accumulations in the area removed

• If it causes vibrations, it should also be turned off until the work is completed
• An inspection must be conducted at the end of the job
• Verify that any spark-producing tools or debris that could enter equipment are removed

Machinery

• All work areas must be kept clean and uncluttered

Work areas

• Sacks, boxes, uninstalled machinery or parts, or other supplies are stored away from areas where the only other combustible material is the agricultural commodity being stored

Packaging

• Must be placed so it does not impede facility housekeeping or fire suppression operations

Miscellaneous storage

Never torch directly to combustible decks or materials

Never torch to areas that cannot be seen fully

Do not use torches near vents or air intakes

Never use a torch to heat a propane tank that begins to frost on the outside

Have appropriate fire extinguishers within easy reach at all times

Whenever working with torch-applied roofing materials, fire-watch inspections must be conducted for at least two hours after the work has been completed and the last torch has been turned off

Typically trailer-mounted devices

Heated using an LPG burner or similar heating device

If the hot contents spill, they can ignite other fuels and spread fire rapidly as a mass of flaming liquid

Adopted fire code will provide requirements

Should have limit controls, tight-fitting lids, and other safety devices to prevent fire or spills

Must never be operated inside a building or on its roof

The area of operation should be identified by the use of traffic cones, barriers, and other suitable means as described in the adopted code

At least one employee knowledgeable about the operation should constantly attend the kettle and be in a reasonable distance with the kettle in sight

An appropriate portable fire extinguisher must be located within 25 feet (7.5 m)

LPG cylinders must be secured; regulators are required

LPG containers for roofing kettles must not be used inside any building

All kettles must have an approved, functional, and visible temperature gauge that indicates the temperature of the material being heated

Must also have a lid over the product tank that should be closed in the event of a fire

At no point should water be used to extinguish these types of fires

Primary hazards are fire and explosion

Fire can occur when vapors from flammable organic compounds are released from leaks in tanks, casks, and equipment

Dust from processing grain and combustion from wood floors, casks, and racks can also cause fires or explosions

A vapor explosion can occur if enough vapors are released in an enclosed space with ignition sources

Open flames

Torch cutting and welding

Sparks (static, electrical, and mechanical)

Hot surfaces

Heat from friction

Radiant heat

Combustible dust

Locally adopted code

Hazmat requirements in fire codes may not apply to distilleries, but the hazmat requirements in the building codes may apply

An occupancy that exceeds the maximum allowable quantities (MAQs) for storage may become a hazardous occupancy

Note venting processes

Make sure the electrical system in rooms where distilling or blending flammable liquids is done conforms to the National Electrical Code Class I Division 1 Hazardous Location for Group D Flammable Liquids

Check for proper ground and bonding technique when pouring ethanol from the storage container to the still container and when decanting large amounts of finished product or byproduct

Note that heaters and natural gas appliances that use pilot lights at least 10 feet away from the pouring and distilling areas

Verify that fire sprinkler systems meet the fire jurisdiction’s requirements