Archive for the ‘FR Terminology’ Category

EN531, EN533 , EN470 and EN1149.

Saturday, January 9th, 2010

 

Many of Fire Retardant fabric products have been independently tested to European (EN) and or International Standard Organisation standards (ISO) to demonstrate that they are flame retardant or slash resistant and these tests are used to obtain CE certification for FR garments.

Details of standards and test methods involved in testing for the relevant properties, and the interpretation of their results, are described below along with illustrations of how tested garments are labelled. FR garment factory operates a full quality system conforming to ISO9001.

For all garments where a claim for some form of personal protection is made must be submitted for independent testing firstly to verify if the fabric being used and garment construction conform to the property(s) claimed and are fit for purpose. If the fabric/article passes the required test(s) it is awarded a CE certification details of which must be shown, along with the makers details by using pictograms, such as those illustrated below, representing the hazard against which protection is being claimed Since 2003 all items that are submitted for CE marking as personal protection equipment must also be examined in accordance with EN340, a general assessment standard described below, as well as the specific standard relating to the property being claimed for that garment.

EN340

EN340 covers dimensional stability of the fabric and the suitability of the garment design for the purpose intended. This standard also the defines toxic, carcinogenic and other materials prohibited from use, or which are allowed to be present only below set levels, in products sold in the European Union. This standard specifies tests that must be carried out on different categories of material. The two main tests applicable to textile fabrics, in addition to dimensional stability, are for the pH value (highly acid or alkaline) and the presence of banned Azo dyes.

Tests for flame spread, heat transfer through a fabric or garment resistance to molten metal splash and build up of static electricity.

EN531, EN533 EN470 and EN1149.

General

The first three of the above standards are means of assessing the degree of resistance to burning of a fabric and/or heat transfer through fabrics from a heat source or molten metals and other similar products. EN1149 assesses the potential for an electrostatic charge to build up on a fabric which could discharge to earth in a possibly hazardous environment.

They are usually referred to in the description and labelling of garments claiming some degree of protection against accidental contact with heat and/or flame and other heat hazards. Such garment labels should contain the letters CE and the pictogram for protection against heat and fire.

The test number of the standard to which the fabric has been tested has to be shown above the pictogram, and the level of performance within the test standard that the fabric achieves has to be shown below the pictogram. Typical labelling is illustrated below .

EN533
EN531

INDEX3 5X40
A B1 C1 D2 E1

CE certification of a flame retardant garment includes, in addition to the verification that the fabric in the garment meets the standard to which it is certified, an assessment of that garments dimensional stability and; its fitness for the purpose intended under EN4340.

EN533:1995 Protective clothing; Protection against heat and flame. Limited flame spread materials and material assemblies.

This standard only covers resistance of a material or assemblies of materials to flame spread, no other properties are considered. It is a basic standard which demonstrates that the fabric tested has flame resistant properties and gives an indication as to the degree of resistance.

The actual method of testing for flame spread is described in standard EN532. This test consists of the application for a fixed time (10 seconds) of a specific propane gas flame, placed horizontally at a fixed distance from the bottom of a vertically suspended strip of the fabric of fixed width (50mm). Once the fabric has been exposed to the flame it is observed for holes in the fabric, the formation of flaming debris and the spread of afterglow (continued burning without flame). The test specimen is then awarded an index level according to its performance with regard to the three properties mentioned above.

Index 1; After testing any remaining flame or any hole in the fabric formed by the flame during testing must not reach the edge of the fabric. There must be no flaming debris. Any afterglow (residual burning) must not spread beyond the area affected by the flame during the test.

Index 2; As index 1 but there most not be any holes in the fabric.

Index 3; As Index 2 but any flaming of the fabric after the flame source has been removed must cease within 2 seconds of the sources removal

EN532; will shortly be replaced by the very similar test ISO15025, which is already the standard test for things such as racing drivers clothing, as the main test for flame retardant properties.

For a fabric to be tested to EN533 it is tested both as received and then also after washing a number of times using the method laid down in standard ISO10528:1995 and dried according to standard ISO 6330:1984. The number of times the fabric has been washed and the temperature of washing is also included in any description of the results. The index level reached and the number of washes and temperature (C) at which the fabric has been washed are also shown below the heat and flame pictogram as no washes x temp used. 5×40 after the index therefore means that the sample tested after washing was washed 5 times at 40C.

Manufacturers will sometimes quote results as tested to EN532, quoting an index level only. This means that the fabric has been put through the flame test without washing and not through the full test method required by EN533.

EN 531:1995 Protective clothing; Protection against heat and flame.

This standard is a more comprehensive standard which includes tests for other properties In addition to testing for limited flame spread. The standard requires, in addition to testing for limited flame spread using EN532, that the fabric must also be tested for one or more of the following additional properties before it can be claimed to meet EN531:

The rate at which convective heat passes through the fabric. The rate at which radiant heat passes through the fabric. How it reacts to having molten aluminium metal poured on it. How it reacts to having molten iron metal poured on it. The labelling of a garment meeting this standard is shown in the general section above.

When testing the fabric for limited flame spread under this standard using test method EN532 the washing requirements of the sample prior to testing are different from those stipulated for EN531. Here the fabric has to be washed only 5 times and dried according to ISO6330:1984. The fabric does not have to be washed prior to testing for other properties.

All performance levels claimed under this standard must include results of tests to EN532, this result must meet Index 3 as described for EN531above and is denoted as A in the list of results below the pictogram. As mentioned above, any product certified to EN531 standard must also have been tested for least one other of the properties listed. These properties are given the letters B, C, D, and E, each letter is followed by a number which indicates the level of performance that the fabric has achieved in the relevant test. Details of the tests used to measure these other properties are described below. If the relevant letter does not appear in the list under the pictogram on a garments label then no claim is made as to the fabric/garments ability to protect against that particular hazard. For example a fabric shown as achieving levels A B1 C1 h as only been tested for limited flame spread and items B and C below.

B Convective heat transfer as tested by method EN367. This involves placing a standard heat source (a flame) a fixed distance in front of the fabric and measuring the time it takes for the temperature on the other side of the fabric to go up by 24C. The equipment is designed to expose the sample to a heat rate of 81 KW per square metre. The temperature rise mentioned is effectively how long it would take before burns would be seen on any skin on the other side of the fabric. Levels ranging from 1 to 5 are awarded in accordance with the time it takes the temperature to rise the required amount, this level is represented as a number after the letter B below the pictogram

C Radiant heat transfer as tested by method EN366. This method is the same as EN367 except that the heat source is radiant (an electric fire bar) which exposes the sample to radiant heat at a rate of 20 KW per square metre. The results graded by levels ranging from 1 to 4. Both tests EN366 and EN367 have a minimum result below which a level cannot be awarded.

D and E; Resistance to molten aluminium and iron splash as tested by method EN373 and EN348. Theses tests involves placing a sample of the fabric to be tested at a steep angle to the horizontal with a sheet of simulated skin (P VC) underneath and pouring a known weight of molten metal over the fabric sample from a fixed height. The test is repeated with increasing weights of metal until the simulated skin shows distortion and/or metal adheres to the fabric. A test level is awarded according to the weight of metal poured when distortion occurs. Again, the level achieved is shown as a number after the letter D (for aluminium) or E (for Iron) below the pictogram.

EN470-1: 1995 Protective clothing for use in welding and allied processes.

This standard involves testing for limited flame spread using EN532 as in the tests above, the fabric must meet index 3 to pass.

Resistance to welding splash is measured using a test method which described as part of EN348 and is a variant of the methods used for EN531 parts D and E. This test involves placing a test specimen of fabric at a specified angle and then heating a specified type of welding rod at a specified distance above the fabric. A thermocouple is placed on the lower side of the fabric under the point where the drops of molten welding rod land on it. The thermocouple measures the increase in temperature of the underside of the fabric as the drops land on the upper surface. The pass level for the test is determined by the number of drops required to increase the temperature on the underside of the fabric by 40C.

This standard also requires the fabric to be tested for tear strength, tensile strength and dimensional stability. Typical work wear fabrics comfortably achieve the pass levels set for these properties

EN1149:1995 Protective clothing; Electrostatic properties. Surface sensitivity (test methods and requirements).

This standard includes the methods to test for a fabrics susceptibility to build up an electrostatic charge on its surface and the speed at which a charge when built up will decay. It is a way of assessing the potential for a spark of static electricity to be discharged from the fabric to earth so causing an explosion or fire. The standard consists of three tests that are referred to as EN1149-1, EN1149-2 and EN1149-3. EN1149-1 and EN1149-3 are the ones most often used.

Before testing the sample is washed 5 times according to BS EN ISO 26330:1994 Procedure 4A using ECE reference detergent and tumble dried using procedure E in a machine with an exhaust temperature less than 50C.

EN1149-1; Horizontal resistance test. The resistance of a fabric is measured across its surface by a modified Ohm meter as illustrated above. The test is a simple pass or fail, the pass is achieved if the resistance measured is less than 510 ohms.

EN1149-2 Vertical resistance test. The resistance of the fabric is measured from one surface to another by a modified Ohm meter similar to that used in part 1 above.

The test is again a simple pass or fail, the pass is achieved if the resistance measured is less than 510 ohms.

EN1149-3; Charge decay test.

A standard static electric charge is developed on the surface of the fabric and the time measured for the charge to decay to half its strength. A fabric passes the test if the time is less than 4 seconds. The pictogram used in labelling for this standard is shown below.

EN1149 1

EN1149- Standards for cut resistant fabrics and garments.

EN388 is the main European standard designed to assess the performance of a fabric or layers of fabric for their ability to resist heavy rubbing, cutting by a blade or sharp object, tearing, and puncture by a pointed object. The test procedure involves carrying out a specific test for each of these properties. A performance level is awarded according to each test result, for example a material with an abrasion resistance of between 100 and 500 cycles would be awarded level 1.

The pictogram for mechanical hazards is used in combination with the test information to show the performance of the fabric or garment.

EN388

2344

On labels showing that when a garment has been approved for CE marking to EN388 standard these test levels are quoted as four numbers below the EN388 pictogram, the numbers are always shown in the order in which the tests are described below. The minimum test results required to achieve the various performance levels shown by the numbers below the pictogram are listed in the table below.

TEST/PROPERTY
PERFORMANCE LEVEL

1
2
3
4
5

ABRAISION RESISTANCE- CYCLES
100
500
2000
8000
-

BLADE CUT RESISTANCE – CUT INDEX
1.2
2.5
5.0
10.0
20.0

TEAR RESISTANCE – NEWTONS
10
25
50
70

PUNCTURE RESISTANCE – NEWTONS
20
60
100
150

Please note the geometric progression between the minimum results required to meet the increasing performance levels. This means, for example, that the increase in test performance required to improve from blade cut index level 4 to index level 5 is eight times that needed to improve from level 1 to level 2. Please also note that where multiple layer materials are involved the abrasion and tear resistance levels are derived form the most resistant of the individual layers, not the combined assembly. Blade cut resistance is the only parameter where a performance level 5 is awarded.

EN388,6.1 – Abraision resistance.

This test is carried out using an instrument known as a Martindale tester in which the material to be tested is placed on a bed and a rubbing head of fixed size and weight, covered with a standard abrasive material, is moved in a circular motion over the test specimen.

Four samples of the material are tested and the test result is the number of cycles required to rub through the material. The standard abrasive material used in this test = is severe in action, it is unusual for textile materials to withstand the 2000 cycles required to meet performance level 3.

The performance level of a single material is decided by the lowest result of the four tests in accordance with the table above. For multiple layer materials each layer is tested separately, the performance level is based on the lowest individual result of the most resistant material.

EN388,6.2 Blade cut resistance.

The instrument used for this test consists of a circular, free rotating blade, under pressure from a standard weight, which is moved backwards and forwards over the surface of the test material over a fixed stroke length. The test result is the number of cycles taken for the blade to cut through the material. To take the sharpness of the blade into account the test is performed using a standard material before and after testing the sample, the mean of these two tests on the standard material is defined as blade cut index 1. The test result is the ratio of the number of cycles required to cut through the sample to the number of cycles required to give blade cut index 1.

Where multiple layer materials are involved the layers are assembled and tested as they would be in the garment. Two test samples are selected, each sample is tested five times and a mean blade cut index calculated from the five tests. The performance level is awarded in accordance with the lower mean blade cut index of the two samples.

EN388,6.3 – Tear resistance.

In this test a sample of material to be tested is prepared in a standard way and clamped in the jaws of a strength testing machine. The jaws are moved apart at constant speed and the force needed to tear the material measured. For single materials the performance level is given by the lowest result of four tests. For multiple layer items each layer is = tested separately, four tests carried out on each material. The performance level = is based on the lowest individual result of the most tear resistant material.

EN388,6.4- Puncture resistance.

This test uses a standard, rounded point which is pushed through the material a fixed speed and the force required for the point to penetrate through the material is measured. Where multiple layer materials are involved the layers are assembled and tested as they would be in the garment. Performance levels are awarded in accordance with the lowest of four test results.

NFPA 2112

Saturday, January 9th, 2010

Around the world hundreds of thousands of employees work with the potential of a flash fire hazard. A majority of these employees companies have implemented some sort of flame resistant clothing program spanning back over the past 30 years. Even as recent as the past 6 years new industry standards have been developed along with improved fabrics to meet these standards.
In 2000, a break through standard was developed call NFPA 2112; Standard on Flame-Resistant Garments for Protection of Industrial Personnel against Flash Fire. NFPA 2112 became one of the first standards to provide minimum performance criteria for flame resistant fabrics and guidelines for testing on instrumented thermal manikins. The guidelines of NFPA 2112 call for testing manikin testing per ASTM F1930; Standard Test Method for Evaluation of Flame Resistant Clothing for Protection Against Flash Fire Simulations Using an Instrumented Manikin. NFPA 2112 calls for testing to be conducted at 3 seconds with a pass/fail rate of 50% under the testing protocols set in ASTM F1930. These are the first real guidelines and criteria created by the industry to better understand and compare the protective performance of flame resistant fabrics.
In evaluating fabric for Protection, Comfort and Value, Fire Retardant fabrics have become important in the Oil, Gas, Petrochemical and Chemical industries. Companies’ employees now can have the comfort & piece of mind by meeting the industry standards and exceeding the performance of normal fabrics.

About flame-resistant clothing

Saturday, January 9th, 2010

 

Since flame-resistant (FR) clothing for petrochemical and utility workers has become the rule rather than the exception, you may be faced with a bewildering array of garment and fabric choices. But before any decisions can be made, you need to know which fabrics and garments are in compliance with your needs. And that means knowing exactly what compliance means, what the performance specifications are, and how they are determined.

Regulatory requirements

The first step toward compliance is knowing which regulations you must meet. Three OSHA regulations are used as the basis of requiring flame-resistant clothing:
1. OSHA’s 1910.269 Maintenance Standard applies to electric utilities and industrial co-generation plants when maintenance is performed on existing facilities. The maintenance standard mandates that personnel who work around energized parts must not wear clothing that, if exposed to an electric arc, could contribute to the extent of burn injury. In simple terms, this means that the clothing cannot ignite, so wearing polyester, nylon rayon, or acetate (unless FR treated) is out of the question.

2. OSHA’s 1910.132 General Duty Clause requires employers to identify risks and protect employees from hazards in the workplace. The rule applies to many types of personal protective equipment, and has been used to cite employers that did not require the use of flame-resistant protective apparel.

3. OSHA’s 1910.119 Process Safety Management Regulation requires employers to assess risk throughout the entire manufacturing process to ensure that the process is safe. While the standard does not specifically require FR clothing, OSHA has used this standard more frequently than the General Duty Clause as the basis of citing employers for not requiring FR clothing.

Performance specifications

Once you know the standards you’re required to meet, it’s important to know the differences between the performance specifications related to the flame-resistant clothing you will provide for employees.

ASTM’s F1506-98 standard performance specification for clothing worn by electric workers requires the fabric to be flame resistant, which means it won’t ignite or continue to burn after exposure to an ignition source. The standard is currently being revised to include the requirement of reporting an Arc Rating.

ASTM’s F1891-98 standard for arc and flame-resistant rainwear applies to flame-resistant, waterproof materials used in rainwear. These garments can be made from coated or laminated fabrics. The standard is currently being revised to include a fabric flammability test more suitable to coated fabrics.

NFPA’s 2112-XX standard for flame-resistant garments for protection of industrial personnel against flash fire is currently under development and will be the first U.S. standard that specifically addresses the need for industrial flame-resistant uniforms. It’s scheduled to be finalized in 2001.

NFPA’s 2113-XX standard regarding the selection, care, use and maintenance of FR clothing, which is also under development, will serve as a sort of user’s guide for industrial flame-resistant clothing. It addresses topics such as purchasing, cleaning, repairs, storage, decontamination, retiring garments and proper use procedures. This standard will require that garments be certified to NFPA 2112.

Test methods

While it’s good to know the various performance specifications, it is meaningless unless you know the test methods used to determine whether fabrics meet these specifications.
Meeting specifications for clothing worn by electric utility workers

ASTM’s F1506-98 fabric specification for clothing worn by electric workers relies upon the FTM 5903.1 Vertical Flammability Test, which determines whether a fabric will ignite and continue to burn after exposure to an ignition source. The test method sets criteria on how the test should be conducted (sample size, number of trials, type of flame, etc.), but does not establish performance requirements. To pass this test and be included in ASTM’s Fabric Specification for Clothing Worn by Electric Workers, the garment must have a vertical flame test maximum of two seconds afterflame and six inch char length when it is new and after 25 home launderings.

Also pending inclusion in F1506 is ASTM’s F1959-99 Arc Thermal Performance Value Test, which measures the amount of thermal protection a fabric would give a wearer if the person was caught in the vicinity of an electric arc. The ATPV is defined as the arc energy required to cause the onset of second-degree burn when a person is wearing the fabric. The higher the ATPV, the more protective the fabric.

This test is only conducted on flame-resistant fabrics to measure protection from the heat and flame by-products of an electric arc. It does not indicate any protection from contact with an electric arc.

Meeting specifications for arc and flame resistant rainwear

ASTM’s Standard for Arc and Flame-Resistant Rainwear (F1891-98) relies on the Vertical Flame Test and the Arc Thermal Performance Values described above. To pass the test and be included in the rainwear standard, garments must have a Vertical Flame Test with a maximum two seconds afterflame and six-inch char length when it is new and after 25 washings.

Meeting specifications for flame-resistant garments for industrial personnel

To meet the pending NFPA 2112-XX standard regarding flame-resistant garments for the protection of industrial personnel against flash fires, garments must meet several tests. Aside from the Vertical Flame Test mentioned above (requirements for this specification are a vertical flame test with a maximum two seconds afterflame and four inch char length when it is new and after 100 launderings), other tests include:

ASTM D4108-87 Thermal Protective Performance (TPP) Test, which measures the amount of thermal protection a fabric would give a wearer in the event of a flash fire. The TPP is defined as the energy required to cause the onset of second-degree burn when a person is wearing the fabric. The higher the TPP, the more protective the fabric. To meet the criteria of this standard, fabric must possess a minimum TPP of six-inch spaced configuration and a minimum TPP of three-inch contact configuration.

Heat resistance or thermal stability requirements mandate that the fabric will not melt and drip, separate or ignite in a 500°F oven for five minutes. Thermal Shrinkage Resistance requirements mandate that fabric will have a maximum ten percent shrinkage after being in a 500°F oven for five minutes.

Garments must also pass the ASTM Flash Fire Mannequin Test for inclusion in the NFPA 2112-XX category. This test is a full-scale mannequin test designed to test fabrics in completed garment form in a simulated flash fire. A mannequin, with up to 122 heat sensors spaced around its body, is dressed in the test garment, then exposed to a flash fire for a pre-determined length of time. Tests are usually conducted at heat energies of 1.8-2 cal/cm2sec, and for durations of 2.5 to 4.5 seconds. Results are reported in percent body burn, with a maximum of 50 percent total body burn indicated when a standard coverall is tested for three seconds with underwear worn under the test garment.

Sidebar: Who sets the standards?

Performance standards are developed by a number of government and non-profit organizations to establish guidelines for protective equipment and procedures for working in hazardous areas. While these standards are not law, they sometimes gain the force of law. Frequently, OSHA and other law-making bodies incorporate voluntary compliance standards into new laws and rules.
Some standards-setting organizations in North America that commonly address protective clothing are:

American Society of Testing of Materials. ASTM publishes both performance specifications and test methods for evaluating protective clothing and equipment. Participants in ASTM are volunteers from industry, testing organizations, and users who have an interest in the topic. Standards and test methods are published by ASTM and renewed every five years.

National Fire Protection Association. NFPA writes voluntary compliance standards related to the Fire Service and other industries. Participants who serve on the committees that write standards are volunteers representing manufacturers, users, testing and special experts. NFPA standards are subject to public comment before publishing, and are renewed every five years.

Canadian Government Standards Board. CGSB is a voluntary compliance organization that is sponsored by the Canadian government. As with NFPA, participants are volunteers representing manufacturers, users and testing, and each committee must have balanced representation. However, only Canadians can be voting members on each committee.

Do You Need 70E?

Saturday, January 9th, 2010

Questions and answers about this set of guidelines for workplace electrical safety.

By John C. Klingler, P.E., Lewellyn Technology, Inc.

 

One of the hot topics in electrical and mechanical training classes is the National Fire Protection Association (NFPA) 70E. Students question what 70E is and how it relates to the National Electrical Code (NEC), if 70E is a new regulation and if not why are they just now hearing about it, and if companies are required to comply with 70E.

This article will take some of the mystery out of 70E.

What is 70E?
Parts of 70E have been around since 1979. The Occupational Safety and Health Administration (OSHA) adopted new regulations on safe electrical work practices in 1990 based on 70E. However, 70E is a topic of interest now because the NEC and OSHA are referring to it in their documents, and citations are now being written based on 70E.

With the passing of the Williams-Steiger Occupational Safety and Health Act of 1970 came the need for occupational safety and health regulations. Congress directed OSHA to develop new regulations using existing “national consensus standards” and established federal standards.

Troubleshooting live equipment, such as testing a contactor (left), requires hazard/risk level 2 PPE, suitable for protection from an arc flash of 8 cal/cm2, but racking of a circuit breaker (right) demands hazard/risk level 3 PPE, suitable for protection from an arc flash of 25 cal/cm2.

For electrical safety regulations it originally adopted the most widely accepted electrical standard in the world—the NEC (National Fire Protection Association’s Standard NFPA 70). However, OSHA encountered several problems in attempting to use the latest editions of the NEC:

• With each new update of the NEC (which occurs every 3 years) OSHA had to go through the extensive legal process of adopting the new NEC edition and risk creating potential conflicts between the adopted version and the published version.
• OSHA needed a regulation that addressed installation, operation, maintenance, and repair in the workplace. The NEC is an electrical installation standard only.
• Because the purpose of the NEC is the practical safeguarding of persons and equipment and because it includes provisions for residential, it contains many provisions that are not relevant to OSHA and only confuse the reader.

To correct these problems and others, NFPA created a committee to develop electrical safety standards that would serve the needs of OSHA. This committee reports through the NEC technical committee and is called the Committee on Electrical Safety Requirements for Employee Workplaces—NFPA 70E. This standard has evolved over time:

• 1979: First edition published with only Part I (Installation Safety Requirements).
• 1981: Second edition added Part II (Safety-Related Work Practices).
• 1983: Third edition added Part III (Safety-Related Maintenance Requirements).
• 1988: Fourth edition had only minor revisions.
• 1995: Fifth edition updated Part I based on the most recent NEC and made some major additions to Part II.
• 2000: Sixth edition updated Part I based on the most recent NEC, made additions to Part II, and added Part IV (Safety Requirements for Special Equipment).
• 2004: The most recent edition made many significant changes including a total reorganization into the NEC format. In the reorganization Part II was moved to become Chapter 1, Part III became Chapter 2, Part IV became Chapter 3, and Part I became Chapt. 4.

Is 70E a “national consensus standard”?
By definition NFPA 70E is a national consensus standard. In 29 CFR 1910.2(g), a national consensus standard is defined as a standard that is developed by the same persons it affects and then is adopted by a nationally recognized organization.

Organizations that publish national consensus standards include the NFPA, American Society for Testing and Materials (ASTM), and the American National Standards Institute (ANSI).

What does it cover?
In NFPA’s catalog it states: “70E covers the full range of electrical safety issues from safety-related work practices to maintenance, special equipment requirements, and installation. In fact, OSHA bases its electrical safety mandates—OSHA 1910 Subpart S and OSHA 1926 Subpart K—on the comprehensive information in this important Standard.”

The 2004 edition of 70E has an introduction, four chapters, and 13 annexes.

Chapter 1, “Safety-Related Work Practices,” is the meat of the 70E document. It discusses qualified vs unqualified persons and training. It requires an electrical safety program, electrical hazard analysis for shock and arc flash, energized electrical work permits, and lockout/tagout procedures. It establishes approach boundaries and discusses how to select appropriate personal protective equipment (PPE) and protective clothing. Arc flash protection also is addressed in this chapter.

Chapter 2, “Safety-Related Maintenance Requirements,” does not create much discussion. It basically requires that electrical components, wiring, and equipment be maintained in a safe condition.

Chapter 3, “Safety Requirements for Special Equipment,” covers batteries, lasers, and power electronic equipment. This chapter affects more installations than one might initially think because power electronic equipment includes electric arc welding equipment, and motor drives, UPS, and lighting controllers that contain rectifiers and inverters. There are no surprises in this chapter but those with the subject equipment should review it.

Chapter 4, “Installation Safety Requirements,” is a truncated version of the NEC. Here authors state that the requirements in Chapter 4 are based on the NEC and in the forward of the 70E document it states that this document is not intended to be used in lieu of the NEC.

Annexes A through M offer useful information including how to calculate flash protection boundaries.

What is the “general duty clause” and how does it relate to compliance?
This clause refers to a portion of the Occupational Safety and Health Act of 1970:

5. Duties
(a) Each employer
(1) shall furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees,
The NEC requires field labeling (above) on equipment where arc flash is a hazard. A future edition of the code may require more extensive labeling (inset) that includes flash hazard boundary and PPE levels.

Section 5(a)(1) has become known as the “general duty clause.” It is a catch-all for citations if OSHA identifies unsafe conditions to which a regulation does not exist.

In practice, OSHA, court precedent, and the review commission have established that if the following elements are present, a “general duty clause” citation may be issued:
• The employer failed to keep the workplace free of a hazard to which employees of that employer were exposed.
• The hazard was recognized. (Examples might include through safety personnel, employees, organization, trade organization, or industry customs.)
• The hazard was causing or was likely to cause death or serious physical harm.
• There was a feasible and useful method to correct the hazard.

Is compliance mandatory?
In 2002, the NEC referenced NFPA 70E for the first time.

NFPA 70-NEC Section 110.16 Flash Protection requires field labeling of switchboards, panelboards, industrial control panels, and motor control centers that are likely to require examination, adjustment, servicing, or maintenance while energized to warn the qualified person of the potential of an arc flash. In Fine Print Note No. 1 that follows 110.16 it refers the reader to NFPA 70E for assistance in determining severity of potential exposure, planning safe work practices, and selecting personal protective equipment.

It is possible and in fact likely that the 2005 NEC may strengthen the language in 110.16 to require specific information on the field labels such as flash boundaries and PPE requirements, which are addressed in 70E. If this happens, facilities complying with the 2005 NEC will need flash hazard analyses completed for all new equipment or will need to default to generic tables provided in 70E to determine the boundaries and PPE requirements.

OSHA regulation 29 CFR 1910 Subpart S Appendix A: Reference Documents also references NFPA 70E:

“The following references provide information which can be helpful in understanding and complying with the requirements contained in Subpart S:

NFPA 70-78 National Electrical Code

NFPA 70E Standard for the Electrical Safety Requirements for Employee Workplaces”

In a “Standards Interpretation” letter from OSHA in 2003 the following is from selected paragraphs:

“All your questions involve the NFPA 70E standard, which is one of many industry consensus standards developed by the National Fire Protection Association. NFPA 70E, which is titled ‘Electrical Safety Requirements for Employee Workplaces,’ is the NFPA’s consensus standard for workplace electrical safety. It covers employee protection from electrical hazards including shock, arc blasts, explosions initiated by electricity, outside conductors, etc.

“With respect to the General Duty Clause, industry consensus standards may be evidence that a hazard is ‘recognized’ and that there is a feasible means of correcting such a hazard.

“These provisions (1910.132(a) personal protective equipment) are written in general terms, requiring, for example, that personal protective equipment be provided ‘where necessary by reason of hazards…’ and requiring the employer to select equipment ‘that will protect the affected employee from the hazards…’.

“Industry consensus standards, such as NFPA 70E, can be used by employers as guides to making the assessments and equipment selections required by the standard. Similarly, in OSHA enforcement actions, they (70E) can be used as evidence of whether the employer acted reasonably.

“Under 1910.135, the employer must ensure that affected employees wear a protective helmet that meets either the applicable ANSI Z89.1 standard or a helmet that the employer demonstrates ‘to be equally effective’. If an employer demonstrated that NFPA 70E contains criteria for protective helmets regarding protection against falling objects and electrical shock that is equal to or more stringent than the applicable ANSI standard, and a helmet met the NFPA 70E criteria, the employer could use that to demonstrate that the helmet is ‘equally effective’.”

In September 1999 a major U. S. corporation experienced an electrical accident that resulted in serious burn injuries to an electrical apprentice employee. OSHA investigated the accident and issued a number of citations. The employer challenged the citations and the disagreement ended up before the Occupational Safety and Health Review Commission.

As part of the citation OSHA contended that the employer violated a federal regulation because it did not provide or require that its electricians wear appropriate flame-resistant or retardant personal protection, specifically, flame-resistant coveralls and insulated gloves. OSHA also contended that the employer violated a regulation when it did not provide or require that its electricians wear appropriate face protection.

In the settlement the employer agreed to develop hazard analyses in accordance with the personal protective equipment provisions contained in NFPA 70E. OSHA agreed that given the present state of its standards and regulations, the hazard analyses would achieve compliance with its requirements.

Points to remember
To summarize, you should understand:

• Several of the OSHA regulations are written in general terms leaving the details up to the employer on how to comply. (An example is requirements for personal protective equipment and clothing in 1910.132(a).) The employer is expected to use consensus standards to help in the selection of the best method to achieve compliance with OSHA regulations. NFPA 70E is a “how to comply” standard for specific OSHA regulations.

• Although NFPA developed 70E for OSHA, OSHA has not officially adopted or incorporated it by reference into its regulations. Instead in 1990, OSHA promulgated new safety-related work practices in 1910.331 based on the information in 70E at that time. However, NFPA has made major changes to 70E based on better information and research since OSHA developed its standard. The bottom-line is that 70E is not a federal regulation; it is just a national consensus standard like hundreds of other standards that are not laws or regulations. But compliance with 70E will assure compliance with specific OSHA electrical regulations.

• Some OSHA state plans are more restrictive than federal OSHA and as such may have adopted or incorporated 70E; however, this is on a state-by-state basis and should be evaluated by employer location. After researching several states on this issue, the responses were too varied to incorporate into this article.

• In the event of an injury or death due to an electrical accident, if OSHA determines that compliance with 70E would have prevented or lessened the injury, OSHA may cite the employer under the “general duty clause” for not using 70E to protect the employee(s). (Shock and arc flash are recognized hazards that employers should be aware of because 70E is now referenced in both the NEC and OSHA regulations.)

• It is important to get training on NFPA 70E and to implement it into your electrical safety program.

NFPA 70E 2000 Compliance for electric arc flash

Saturday, January 9th, 2010

70E 2000 compliance standard issues for electrical maintenance and contractors.

Workers in the electrical maintenance and electrical contractor Industry are being exposed to the risk of an electric arc flash fatality or injury.
Many workers are unaware of the potential hazards associated with the possibility of electrical arc hazards and must be made aware of the potential consequences.

Employees who are not properly protected through the 70E 2000 compliance standard may be subject to the affects and consequences of an electric arc flash.

An electric arc flash consists of a short circuit through the air that originates from electrical equipment sources. The results can be in the form of air born pieces of metal causing injury to workers and severe burns due to the amount of arc flash energy that is generated.

The general industry electrical installation standard has not been updated since 1981, so it is important that we update these requirements to reflect the most current practices and technologies in the industry,” said OSHA Administrator John Henshaw. “These changes will strengthen worker protections and help eliminate inconsistencies and possible confusion between OSHA’s requirements and many state and local building codes which have adopted updated NFPA and NEC provisions.”

Proposed changes to OSHA’s general industry electrical installation standard (1910 Subpart S) focus on safety in the design and installation of electric equipment in the workplace. The changes draw heavily from the 70E 2000 edition of the National Fire Protection Association’s (NFPA) Electrical Safety Requirements for Employee Workplaces (NFPA 70E), and the 2002 edition of the National Electrical Code (NEC).

The NFPA 70E 2000 compliance standard will help eliminate some of the risk to workers exposed to electric arc hazards.
Although the 70E compliance standard may seem a burden to some due to the costs of increased PPE it can be looked at as a type of arc flash insurance. Companies that do not comply with the 70E 2000 compliance standard may be subject to claims for personal injury and incidents resulting to death. This could therefore cost millions of dollars in legal costs.
Downtime may also come into affect due to the electrical arc incidents that have occurred through flashes resulting in thousands of dollars per minute.

Electric Arc Flash has become more of a concern through the requirement of increased power consumption for Industrial applications. For this reason the 70E 2000 compliance standard has that much more benefits for the applications involved.

Electrical arc flash hazards do not just occur in the presence of high voltage industrial facilities. Locations consisting of many low voltage equipment sources actually account for the most electrical arc flash ocurrences.

It may be that electrical personal do not realize this increased risk of electrical arc flash exposure through lack of information about the 70E 2000 compliance standards and the potential consequences of non compliance.

OSHA, enforces safety practices in the workplace. Its 29 Code of Federal Regulations Part 1910.333 states, in part, “Safety related work practices shall be employed to prevent electric shock or other injuries resulting from either direct or indirect electrical contacts…” Traditionally, many electrical contractors have guarded primarily against electrical shock and electrocution. Many of them believe that if they don’t touch something that can shock them, then they are protected from an electrical arc flash. Clearly however, arc flash doesn’t require an electrical worker to touch a piece of energized equipment in order to be harmed; it is an example of the “other injuries” included in OSHA 1910.333.

Due to the implications of the hazard of electrical arc flash the 70E 2000 compliance standard will help promote the requirement of employee safety training for arc flash hazards.

Safety programs should involve standard practices for employees that may come into contact with electrical arc flash hazards. The use of the appropriate PPE and standards for the operation of the electrical equipment must be implemented through guidance included in the 70E 2000 compliance standards.

Proper standard practices should be integrated into employee training programs to comply with the NFPA 70E 2000 standards. These programs should focus on such issues as on the job 70E 2000 compliance in the form of proper use of PPE associated to the electrical job task at hand.
Electrical contractors coming on site to work that may be exposed to electric arc flash must be informed of the local safety program in order to be in compliance with the 70E 2000 standards.

As most standard practice procedures will state that the best way to prevent electrical arc flash incidents from ocurring is to lock-out or de-energize the equipment. Industry standards are now focusing on the incidents where the electrical power can not be turned off. This is where the 70E 2000 compliance standard will help ensure the safety of the workers involved.
The NFPA 70E 2000 compliance standard states that electrical workers must de-energize equipment to be worked on except in critical situations where the power must be left on.

NFPA 70E 2000 also provides tables that will determine the PPE required for certain electrical arc flash situations based on the voltage involved with the equipment being worked on.

Also of note is the OSHA and NFPA 70E standards that require that equipment to be worked on must be put into a state of being de-energized as to avoid electrical arc flash exposure.

The use of proper PPE for the task of pre de-energizing of electrical equipment is a safety precaution that must never be over looked.

The fact that electrical arc flash protection apparel can some times be viewed as uncomfortable can be lead to the PPE not being worn by the electrical workers. The 70E 2000 compliance standards have been introduced to protect the worker for this reason.

Pre de-energizing of electrical equipment must be performed while still in an energized state. This can lead to the possibility of an electric arc flash occurring that could cause a fatality. The use of large uncomfortable electrical PPE is a small price to pay for the insurance that a worker can return HOME safely on any given day.

The 70E 2000 compliance standard considers the fact that the risk of an electrical arc flash may ocurr within a certain area surrounding the source of electrical discharge points.
This potential arc area is determined by a number of parameters those being the voltage, current and distance from the electrical equipment.

The proper electrical arc PPE required for the job task can be determined by the use of certain software or NFPA 70E provides a table that can determine the arc risk. The table will determine the calories per square centimeter which is how the potential of electrical arc is measured.
Once this is established the appropriate PPE can be issued.

Specific software programs are available that provide a much more accurate calculation compared to the NFPA 70E tables. The NFPA 70E compliance tables can sometimes under estimate the CAL rating due to fluctuations in energy source.

NFPA 70E has established the requirement of an on site safety program that ensures adequate electrical arc PPE is available and worn by workers.
Electrical arc can cause fatalities and/or serious burn injuries to those exposed to the area of concern.

For this reason every facility must conform to the NFPA 70E compliance for work place safety.

Fire Retardant Fibers

Sunday, January 3rd, 2010

 

Acrylic – is commonly called acrylic glass, simply acrylic, perspex or plexiglas. Chemically, it is the synthetic polymer of methyl methacrylate (PMMA). The material was developed in 1928 in various laboratories and was brought to market in 1933 by Rohm and Haas Company. PMMA is often used as an alternative to glass, and in competition with polycarbonate (PC). It is often preferred because of its moderate properties, easy handling and processing, and low cost, but behaves in a brittle manner when loaded, especially under an impact force. To produce 1 kg of PMMA, about 2 kg of petroleum is needed. PMMA ignites at 460 °C and burns, forming carbon dioxide, water, carbon monoxide and low molecular weight compounds, including formaldehyde.

Aramid – Aramid fibers are a class of heat-resistant and strong synthetic fibers. The name is a shortened form of “aromatic polyamide”. They are fibers in which the chain molecules are highly oriented along the fiber axis, so the strength of the chemical bond can be exploited. Aromatic polyamides were first introduced in commercial applications in the early 1960s, with a meta-aramid fiber produced by DuPont under the tradename Nomex. This fiber, which handles similarly to normal textile apparel fibers, is characterized by its excellent resistance to heat, as it neither melts nor ignites in normal levels of oxygen. It is used extensively in the production of protective apparel, air filtration, thermal and electrical insulation as well as a substitute for asbestos. Meta-aramid is also produced in the Netherlands and Japan by Teijin under the tradename Teijinconex, in China by SRO Group (China) under the trade name X-Fiper , Yantai under the tradename New Star and a variant of meta-aramid in France by Kermel under the tradename Kermel.

Based on earlier research by Monsanto Company and Bayer, a fiber – para-aramid – with much higher tenacity and elastic modulus was also developed in the 1960s-1970s by DuPont and Akzo Nobel, both profiting from their knowledge of rayon, polyester and nylon processing. DuPont was the first to introduce a para-aramid called Kevlar in 1973. A similar fiber called Twaron with roughly the same chemical structure was introduced by Akzo in 1978. Due to earlier patents on the production process, Akzo and DuPont had a patent war in the 1980s. Twaron is currently owned by the Teijin company.

Kevlar – A registered trademark of DuPont for a light, strong para-aramid synthetic fiber, related to other aramids such as Nomex and Technora. Developed at DuPont in 1965, it was first commercially used in the early 1970s as a replacement for steel in racing tires. Typically it is spun into ropes or fabric sheets that can be used as such or as an ingredient in composite material components. Currently, Kevlar has many applications, ranging from bicycle tires and racing sails to body armor because of its high strength-to-weight ratio. Famously coined: “5 times stronger than steel on an equal weight basis”. A similar fiber called Twaron with roughly the same chemical structure was introduced by Akzo in 1978, and now manufactured by Teijin.

Neoprene – or Polychloroprene is a family of synthetic rubbers that are produced by polymerization of chloroprene.[1] It is used in a wide variety of applications, such as in wetsuits, laptop sleeves, orthopedic braces (wrist, knee, etc.), electrical insulation, liquid and sheet applied elastomeric membranes or flashings, and car fan belts. Neoprene is the trade name used by DuPont Performance Elastomers.

Nitrile Rubber – A synthetic rubber copolymer of acrylonitrile (ACN) and butadiene. Some trade names are: Nipol, Krynac and Europrene. Although its physical and chemical properties vary depending on the polymer’s composition of nitrile (the more nitrile within the polymer, the higher the resistance to oils but the lower the flexibility of the material), this form of synthetic rubber is generally resistant to oil, fuel, and other chemicals.

Nomex IIIA – A registered trademark of DuPont and developed in the early 1960s. It is a blend of 93% meta-aramid (Nomex), 5%para-aramid (Kevlar), 2% P140 (anti-static carbon) (93-5-2). Nomex, a synthetic flame retardant (FR) fibre, is combined with Kevlar for strength and P140 for anti-static qualities. Nomex IIIA is inherently resistant to flames, dissipates static, and is resistant to many chemicals including organics, acids, and bases. The fire resistance does not wash out during laundering.

Nomex Care Label – Nomex IIIA provides outstanding built-in flame and static resistance. CAUTION: Flammable contaminants will reduce the thermal performance of any flame resistance garment. For maximum protection: Wash your new garment before wearing and after each subsequent wearing to thoroughly remove potentially flammable fabric processing aides/finishes, greases, oily and other flammable contaminants. Wearing undergarments is recommended with all flame resistance garments. Anti-static garments of Nomex IIIA should be used in conjunction with proper procedures for maximum protection against the threat of spark. Do not remove garments when in a hazardous environment. INSTRUCTION ON CARE OF GARMENT: Garments of DuPont Nomex can be cleaned by home or commercial laundry or dry cleaning procedures without loss of their outstanding inherent protective features. The following suggestions will keep your garments looking neat, attractive, and safe. For correct fit, try garment on before washing or wearing. Wash garments after each wearing to remove any flammable contaminants. If home procedures do not remove contaminants, commercial laundering or dry cleaning is recommended. Launder garments of Nomex only garments of Nomex to help avoid surface entrapment of flammable lint. Pre-treat greasy stains and collar/cuff lines. Wash garments in hot water with a heavy-duty detergent. Do not overload home laundry equipment. Do not use chlorine bleach or detergents containing chlorine bleach. Chlorine bleach may cause excess fading and reduce fabric strength. However, chlorine bleach will not affect the flame resistance of nomex. Tumble dry garments at a low setting. Use the cool down cycle if available. Remove and hang garments as soon as tumbler stops. Do not hang in direct sunlight – sunlight can cause fading. When using proprietary laundry aids, be sure to read and follow carefully the manufacturer’s instructions. Nomex is a registered trademark of the DuPont Company.

Vinyl – Any organic compound that contains a vinyl group (also called ethenyl). It is a tough and flexible plastic; used to make a wide variety of products such as pipes, floor coverings and protective apparels.