Flame-resistant (FR) clothing and protective equipment are essential for workers in high-risk professions.
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Arc flash and flash fire hazards pose serious dangers that must be addressed through the proper use of FR gear that meets key standards.
This comprehensive article provides an in-depth look at NFPA 70E and NFPA 2112, two crucial standards for flame-resistant clothing.
The Vital Role of FR Clothing for Firefighters
Firefighters routinely face extreme arc flash and flash fire hazards when responding to emergencies. Their specialized protective clothing and equipment are all that shields them from severe or even fatal burn injuries.
Durable, reliable flame-resistant knee pads are a critical component of firefighter turnout gear. The knee pads must withstand repeated exposure to high temperatures and flames while allowing freedom of movement.
Common pad materials include leather, rubber, Kevlar, and modern composites. These provide essential abrasion resistance, impact protection, and flexibility under demanding emergency conditions.
Proper fit and sizing of knee pads are also vital to prevent excess wear and ensure full protective coverage during fire ground operations.
When lives are on the line, firefighters need to trust their safety equipment to perform and protect when facing flashover, backdraft, and other thermal hazards.
Overview of Key Terminology: Arc Flash vs. Flash Fires
- Arc Flash – An arc flash occurs when a high-amp current passes through the air between conductors, creating an explosive release of heat and light energy. Temperatures in an arc flash event can exceed 35,000°F. The massive energy release can vaporize metal, cause severe burns, and trigger secondary fires and explosions.
- Flash Fire – A flash fire is characterized by the rapid burning of a diffuse fuel source such as airborne dust or methane gas. The lack of containment around the fuel allows extremely fast flame propagation. Flash fires can engulf a room in flames in less than one second, with temperatures exceeding 2000°F.
Common misconceptions exist about the level of burn injuries caused by flash fires. Because the duration of a flash fire is very short, there is a perception that the clothing worn makes little difference.
However, research studies have shown that garment material significantly influences the severity of burns sustained in a flash fire incident.
While the total heat exposure time is very brief, melt-dripping fabrics like unmodified cotton and polyester/cotton blends can worsen contact burns and the adhesion of melted material to the skin.
OSHA Regulations for Hazardous Materials and Fire Protection
The Occupational Safety and Health Administration (OSHA) outlines various regulations regarding hazardous materials handling and fire protection. These include:
OSHA 1910.132 – The Personal Protective Equipment (PPE) standard establishes the employer’s duty to assess workplace hazards and provide appropriate PPE to control identified risks.
OSHA 1910.269 – Covers the use of PPE and insulating equipment to protect employees working on or near exposed energized parts of electric power generation, transmission, and distribution systems.
For protection against flash fire hazards, OSHA prohibits clothing made from materials that are readily combustible or melt. This includes:
- Untreated cotton
- Wool, silk, and other animal-derived fibers
- Thermoplastic materials like polyester, nylon, and acrylic.
Acceptable flame-resistant materials per OSHA include:
- Flame-resistant cotton
- Wool and cotton blends treated with FR chemistry
- Inherently flame-resistant fabrics like Nomex, Kevlar, and PBI blends
Startling Statistics on Burn Injuries and Fatalities
Burns are one of the most severe and painful injuries that workers can face on the job. Some alarming statistics help underscore the dangers:
- Over 500,000 burn injuries occur annually in North America.
- More than 10,000 workers are hospitalized each year for treatment of major burn injuries.
- Between 700-800 deaths per year are caused by fires and burns.
- Electrical burns account for approximately 1,000 injuries and 4% of burn deaths annually.
OSHA regulations like 1910.269 mandate the use of appropriate flame-resistant protective clothing and equipment in hazardous electrical work environments to reduce risks.
Employers must provide suitable FR clothing and PPE based on the specific hazards present and ensure it is used correctly by employees.
Proper FR gear can dramatically reduce the occurrence and severity of burn injuries.
Overview of Relevant NFPA Standards for FR Clothing
The National Fire Protection Association (NFPA) develops and publishes codes and standards designed to minimize dangers from fire, chemicals, explosions, and electricity.
Two key standards related to FR clothing are:
NFPA 70E – Standard for Electrical Safety in the Workplace
Focuses on FR clothing requirements and design criteria aimed at reducing burn injuries resulting from an electric arc flash event.
NFPA 2112 – Standard on Flame-Resistant Clothing for Protection Against Flash Fire
Specifies FR clothing performance requirements and testing to evaluate resistance to flash fire exposure.
Both standards are crucial for selecting FR workwear and PPE with appropriate protective properties for the hazards involved.
Detailed Overview of the NFPA 70E Standard
First issued in 1979 and updated frequently, NFPA 70E outlines requirements for protecting personnel from electrical arc flash hazards. Key aspects include:
Scope: This applies to any employee working on or near exposed electrical conductors or circuit parts that could pose an arc flash hazard. Aims to reduce the risk of injury from energy released from electrical equipment failures.
Hazard Risk Categories: Defines Hazard Risk Category (HRC) levels from 0-4, with 4 being the highest risk. Used to determine minimum FR clothing requirements.
ATPV Ratings: Specifies minimum Arc Thermal Performance Value (ATPV) and energy absorption ratings required for FR clothing and PPE based on the applicable HRC. ATPV quantifies the ability to withstand heat energy from an arc flash.
Testing Criteria: Set testing benchmarks for flame resistance, thermal shrinkage, and arc rating that FR fabrics must meet. Tests evaluate vertical flammability, arc thermal performance value, and energy absorption.
Detailed Overview of the NFPA 2112 Flash Fire Standard
First issued in 2007 and updated in 2018, NFPA 2112 specifies the minimum performance requirements and certification criteria for flame-resistant garments that protect against flash fire exposure.
Scope: This applies to FR workwear worn by personnel potentially exposed to momentary flashes resulting from ignitions of flammable gases, liquids, or solids.
Performance Criteria: Limits predicted body burn to ≤ 10% of body surface area when exposed to a 3-second flash fire. Limits heat transfer through all garment layers.
Testing Rigor: Requires third-party certification of fabrics and garments. Multiple test methods evaluate performance.
Layering: Dictates FR requirements for garment outer shells, inner linings, hoods, gloves, footwear, etc. – addressing the protection of each body part.
Key Factors for Standards Compliance
To meet NFPA 2112 criteria, both the flame-resistant fabric used and the finished garment itself must comply and be certified. NFPA 70E focuses more on fabric compliance than the completed garment design.
- For NFPA 2112 compliance:
- Fabric materials and construction must pass rigorous flash fire testing.
- The completed garment design also requires flash fire and heat transfer testing.
- For NFPA 70E compliance:
- The primary focus is on testing the vertical flammability and arc rating of FR fabrics used.
- Less emphasis on finished garment requirements.
Compliance is validated through third-party certifications:
- UL certified per NFPA 2112
- UL or independent lab certified to meet NFPA 70E
Look for markings like UL, SEI, or other indicators confirming testing to the applicable standard(s).
Critical Test Criteria for Both Standards
NFPA 2112 mandates testing to evaluate:
- Vertical Flammability – Assesses if material drips, melts, or ignites when exposed to direct flame.
- Heat Transfer Performance – Measures resistance to convective and radiant heat when subjected to flash fire exposure.
- Manikin Testing – Using instrumented manikins, assess the predicted percentage of body burn when the garment is exposed to a 3-second flash fire.
NFPA 70E requires testing for:
- Vertical Flammability – Same criteria as NFPA 2112.
- Arc Thermal Performance Value (ATPV) – Quantifies the amount of heat energy (in cal/cm2) that a fabric can endure before allowing burn injury. Minimum ratings dictated by Hazard Risk Category.
- Energy Absorption (cal/cm2) – Related to ATPV. Measures how much heat energy per area a fabric can absorb.
Misleading Marketing Claims to Watch Out For
When researching and selecting FR protective apparel, be alert for misleading claims including:
- Implying that everyday workwear meets flash fire resistance criteria, without certification.
- Citing outdated flammability standards like NFPA 701 or NFPA 702 that are insufficient for flash fire hazards.
- Making exaggerated claims about “100% FR” properties when only the outer shell fabric is FR, not the garment layers.
- Misrepresenting arc rating levels of FR fabrics.
The best way to cut through marketing hype is to verify technical data and claims directly with manufacturers. Ask to see official certification documents. Don’t rely solely on promotional catalog language and web content when choosing FR protective gear.
The Critical Need for Compliant FR Protective Gear
The potential hazards posed by arc flash and flash fire events warrant the utmost care and diligence in selecting protective garments and equipment that provide certified, tested flash fire resistance meeting NFPA 2112, as well as arc flash protection meeting NFPA 70E.
Prioritizing high-quality, durable FR and arc-rated gear from reputable, trusted brands is imperative for safety on the job. When lives are at stake, there is no room for sub-standard, questionable protective equipment. Compliance, quality, durability, and comfort are paramount for FR workwear.
NFPA 70E and NFPA 2112 set rigorous standards for flame-resistant apparel designed to minimize burn risks and life-threatening injuries.
Understanding the specifications, test methods, applications and limitations of each standard allows safety managers and workers to make informed decisions when choosing appropriate FR workwear and PPE.
With electrical and flash fire hazards ever-present in many occupations, proper use of NFPA-compliant FR clothing provides an indispensable barrier and line of defense against tragic accidents.
Workers in high-risk roles deserve dependable protection as they put their lives on the line.