Flame Retardant

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HEAT AND FLAME PROTECTION

EN ISO 11612 ABCDEF
> Supersedes EN 531

This standard specifies the performance requirements for garments that protect the body from heat and flame (except the hands).

There are 6 categories:
1. A 1 – A1 = Surface Ignition, B = Bottom Edge Ignition
2. B 1 – 3 Convective Heat
3. C 1 – 4 Radiant Heat
4. D 1 – 3 Molten Aluminium Splash
5. E 1 – 3 Molten Iron Splash
6. F 1 – 2 Contact Heat

Note that the lower the denominator, the poorer the performance.

In Detail:
European standard for garments that protect the user in the event of contact with hazardous heat and flames. The standard is relevant for industrial workers and electricians. If chemicals or flammable liquids are accidentally splashed on the garments, the wearer should immediately move away from the affected area and carefully remove the garments, ensuring that the chemicals or liquid do not come into contact with any part of the skin.

Design Demands:
20cm overlap jacket and trousers. Limited flame spread and heat resistance on internal pockets, linings, labels, badges, retro reflectives etc. Use an overall, two-piece jacket and trousers, or a jacket, bib and brace that are approved to this standard. Two-piece protective clothing must be worn together to provide the specified level of protection.
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Fabric Demands:
General requirement: mechanical strength and heat resistance at a temperature of 180°C: the material shall not ignite or melt and shall not shrink by more than 5%.

Code Letter A 1 – Surface Ignition, ISO 15025A
- No specimen shall give flaming to the top or either side edge
- No specimen shall give hole formation
- No specimen shall give flaming or molten debris
- The mean value of after flame time shall be ≤ 2 s
- The mean value of after glow time shall be ≤ 2 s

Code Letter A 2 – Edge Ignition, ISO 15025B
- No specimen shall give flaming to the top or either side edge
- No specimen shall give flaming or molten debris
- The mean value of after flame time shall be ≤ 2 s
- The mean value of after glow time shall be ≤ 2 s

Code Letter B – Convective Heat, ISO 9151
The garment's protection against convective heat transfer is tested and approved under ISO 9151. Convective heat means the heat that passes through the garment on contact with flame. If there is an outer fabric that does not burn, injury may nevertheless be incurred due to the heat that forms when the fabric, and indirectly the body, comes into contact with the flame.

Code Letter C – Radiant Heat, ISO 6942
The garment's protection against radiant heat transfer is tested under ISO 6942. Low heat radiation over a long period can result in a risk of injury. Therefore, the degree to which the garment lets heat through must be tested against radiant heat.

Code Letter E – Molten Iron Splash, ISO 9185
The protection provided by the fabric against molten metal splash is tested under ISO 9185. Even though the fabric does not burn and disintegrate when in contact with melted metal, burn injury to the wearer can nevertheless occur. This test gives an indication of how much metal splash the garment can take while still affording the wearer protection.

Code Letter F – Contact Heat, ISO 12127
The garment's protection against contact heat transfer is tested under ISO 12127 at a temperature of 250˚C.

USER INFORMATION
Garments should always be worn as a complete set, consisting of a particular jacket and trousers/bib and brace in order to ensure maximum protection. In the event of accidental splashing with chemicals or flammable liquids, the wearer should immediately withdraw from the work area and carefully remove the garments, ensuring that the chemical or flammable liquid does not come into contact with the skin. The clothing must then be cleaned or taken out of use. In the event of a molten metal splash, the user must leave the work area immediately and remove the garments. Note that the garment may not eliminate all risk of burns if worn next to the skin.

LIMITED FLAME SPREAD PROTECTION

> Supersedes EN 533

This protective clothing is intended to protect workers against occasional brief contact with small flames. The working circumstances offer no significant heat hazard and there is no presence of another type of heat.

Index 1 = the flame does not spread, there are no flaming debris, no after glow, a hole may be formed
Index 2 = the flame does not spread, there are no flaming debris, no after glow, no hole formation
Index 3 = the flame does not spread, there are no flaming debris, no after glow, no hole formation, and the after flame time of each individual specimen is less than 2 seconds

In Detail:
European standard for garments where there is risk of ignition. The garment should be used with a jacket and trousers or coverall made from flame-retardant fabric approved in accordance with EN ISO 11612, in order to give the intended protection. The garment is not designed for protection against convective heat, radiant heat or molten metal and similar hazards.

Design Demands:
- 20cm overlap jacket and trousers
- No turn-ups
- Thermally conductive material that is likely to be exposed to heat shall not be in contact with the skin when the garment is closed

Fabric Demands ISO 15025:
Demands for mechanical strength and for flame and heat resistance are defined according to three Index levels, with Index 3 being the highest.

Index 1
• No specimen shall give flaming to the top or either edge
• No specimen shall give off flaming debris
• No afterglow shall spread after the cessation of flaming

Index 2
Same as Index 1, and in addition:
• No specimen shall show hole formation

Index 3
Same as Index 1, and in addition:
• The mean value of after flame time shall be = 2 s.

USER INFORMATION:
If protective garments are Index 1, they must be worn over Index 2 or 3 garments or over ISO 11612 garments.

WELDING & ALLIED PROCESSES PROTECTION

EN ISO 11611

> Supersedes EN 470-1

Designed to protect the wearer from droplets of molten metal, short contact with flame, radiant heat from arc; the clothing minimises the possibility of electrical shock up to 100V DC voltage. There are two classes with specific performance requirements:

• Class 1 (lower level): less hazardous welding situations. Tested with 15 molten metal drops
• Class 2 (higher level): more hazardous welding situations. Tested with 25 molten metal drops

Also, each procedure A1 + A2 must be tested for ISO 15025 for flame spread.

In Detail:
European standard for garments that protect the user when welding or carrying out similar work.

Fabric Demands:
The demands for mechanical strength and for resistance to flame and heat are divided into two classes.

Class 1:
For less hazardous techniques and situations, causing lower level of spatter and radiant heat. Suitable for manual welding techniques with light formation of splatters and drops, e.g. gas welding, TIG, MIG, micro plasma welding, brazing, spot welding and MMA welding. The material must be able to withstand at least 15 drops of molten metal without exceeding an increase in temperature of 40 degrees on the reverse of the material.

Class 2:
For more hazardous welding techniques and situations, causing higher levels of spatter and radiant heat. Suitable for manual welding techniques with heavy formations of splatters and drops, e.g. MMA welding (with basic or cellulose covered electrode), MAG welding (with CO2 or mix gas), MIG welding (with high current). The material must be able to withstand at least 25 drops of molten metal without exceeding an increase in temperature of 40 degrees on the reverse of the material.

Design Demands:
The construction of the garment is based on 13 different design requirements in the standard. For example, the design must reduce the risk of the garment accumulating welding splatter etc., so these garments lack some of the pockets and functions found on other garments.

USER INFORMATION:
It is important to choose a garment of the correct class to suit your work. With the use of additional, partially protective garments, the basic garment must meet at least Class 1 standard. Use an overall, two-piece jacket and trousers, or jacket and bib and brace that are approved to this standard. Two-piece protective clothing must be worn together to provide the specified level of protection.

The garment does not provide protection from direct contact with all parts of arc welding installations carrying welding voltage. It is designed to provide protection against short-term, accidental contact with live electric conductors at voltages up to approximately 100V DC. The garment is not designed to offer protection against electric shock. If there is an increased risk of electric shock in your working environment, additional insulation layers will be required. Be careful when welding in a limited space where there could be a greater concentration of oxygen – this will reduce the flame-retardant properties of the welder's protective clothing. Additional partial body protection may be required in some circumstances, e.g. for welding overhead.

Information on UV radiation hazards:
Class 2 garments are designed to be more resistant than Class 1 garments but this resistance cannot be precisely quantified. Users exposed to UV radiation are to be made aware of the risks and the need for regular checking:

• A simple way to check whether this type of clothing is still protecting against UV radiation (to be carried out weekly, for example) is to hold the garment up to the light of a 100W tungsten bulb at arm's length (approximately 2m away from bulb). If any light can be seen through the fabric, UV will be able to penetrate it too.
• Similarly, users should be advised that if they experience sunburn-like symptoms, UVB is penetrating. In either case, the garment should be replaced, and the use of additional, more resistant protective layers should be considered.

ELECTROSTATIC PROTECTION

EN 1149-5

European standard for protective clothing with antistatic characteristics. The clothing protects against sudden discharges of electrostatic energy and should be worn whenever there is a risk that static sparks may ignite inflammable substances such as gas and oil.

The article should cover all other materials that do not provide protection against static electricity. Thin attachments such as labels, reflectors and the like, must be attached permanently.

Conductive parts, such as buttons and zips, are permitted provided that they are covered completely by the protective material against discharges of electrostatic energy.

EN1149-1 measure of surface resistivity – treated material
EN1149-3 measure of charge decay – core conductor

In Detail:
European standard for garments that protect against electrostatic charge where there is a risk of explosion e.g. in refineries.

Fabric Demands:
An electrostatic dissipative material shall meet at least one of the following:
• T50 < 4s ore s > 0,2, En 1149-3
• Surface resistance = 2,5 ×109 ohm, En 1149-1
• The distance between the conductive threads contained in the material must not be greater than 10mm.

Design Demands:
• The garments must permanently cover all material that does not provide electrostatic protection.
• Thin additions, such as labels and reflectors, must be permanently sewn on. No loose-hanging parts are permitted.
• Elements that conduct electricity (zips, buttons, etc) are permitted if they are completely covered by the electrostatic protective material.

USER INFORMATION:
When using these garments, the wearer must be properly earthed. The resistance between the wearer and the earth shall be less than 108Ω. This can be achieved by wearing suitable footwear. Antistatic footwear approved to
En ISO 20344 or EN 20345 must be used.

Electrostatic dissipative protective clothing shall not be opened or removed in flammable or explosive atmospheres or while handling flammable or explosive substances. Wear and tear, laundering and any contamination can affect the electrostatic dissipative performance of the electrostatic dissipative protective clothing. The garment shall permanently cover all non-compliant material during normal use. The garment should only be used in rooms with increased oxygen content following approval from the relevant safety engineer. Do not make alterations to the garments. Minor embroidery or transfer is permitted on fabric certified to En 531/En ISO 11612 and shall be permanently attached to the garment so that separation is avoided.

The Arc Flash Standards

IEC61482Protective Clothing against the Thermal Hazards of Arc Flash

EN Norms and Technical Requirements

Awareness of Arc Flash hazards and the protective clothing required is increasing in industry sectors where these hazards exist and in this document we hope to clarify some questions that you may have.

It is important to remember that any PPE is always a 'last line of defence' and that any protective clothing you provide to your workforce should be the result of first analysing your systems and procedures in order to minimise any risks present.

What is an Arc Flash?

An arc flash is a discharge of electrical energy that occurs in a fraction of a second and is caused by a short circuit through a gas - usually air - between conductor/s and the ground which results in hazards such as:

• Extreme Heat – 35,000°F (19,400°C)

• Fire with devastating results

• Flying debris including molten metal fragments

• Blast pressure upto 2000lbs/sq ft

• Sound blast upto 140dB – as loud as a gunshot

• Toxic fumes and smoke

• Plasma emission

• Extremely bright light including UV light

The results of an arc flash can clearly be very extensive and include severe burning, hearing loss, shrapnel wounds, shock hazards, memory loss and other physical injuries from being thrown across a work space.

Ensuring your PPE is CE certified

CE Marking and Article 11B Auditing

Arc Flash protective clothing is classified as Category 3 PPE (of Complex Design) under the EC Directive 89/686/EEC Personal Protective Equipment and any production is subject to an EC quality assurance system to ensure continuous conformity of each item.

These garments are not only CE marked but also carry a 4 digit number after the CE mark which indicates the notified body responsible for these Article 11B quality audits.

ENV 50354 – the old standard

This EN Norm tested fabrics and garments against an Arc which was generated in a box made of plaster to simulate what would happen if an electrical arc of 4 kA or 7 kA happened within switch gear or other

enclosed low voltage equipment. This test did not include any analysis of the differential between the measured heat transfer and the Stoll curve – this is now an essential part of the new IEC61482 standards. Stoll curve analysis is used to predict the likelihood of second degree burns to the wearer.

The new Arc Flash Standards

IEC61482-1 and the identical EN 61482-1 are split into two separate parts which cover the methods for testing of fabrics and garments that are designed to protect against the thermal hazards of an Arc Flash.

IEC61482-1-2/EN 61482-1-2 Test Method - Box Test

This test method supersedes ENV50354 and is commonly referred to as the Box Test. There are two test methods – one for fabrics which includes heat transfer measurements and Stoll curve differential analysis and one for the finished garment which includes a visual assessment and performance of components.

The Box Test method gives a protective classification of:

Class 1 – testing at an arc current of 4 kA and duration of 0.5s – Lower Level of Protection
Class 2 – testing at an arc current of 7 kA and duration of 0.5s – Higher Level of Protection

Note – the current of the actual electrical arc event is usually lower than the fault current of the equipment.

Unlike the ATPV Open Arc Test Method, the results of the Box Test are either a Pass or Fail and do not give a value of the incident

energy. (See below on how the test results of the Open Arc Test are measured). However, the Box Test method enables the garment to be CE certified to one of the two classifications (Class 1 or Class 2) according to the results.

This Test Method is referred to for Low Voltage systems only – e.g. to replicate the potential hazard found in many service boxes or cabinets where the arc exposure is potentially directed at the front of the worker at the height of the breastbone.

The user must however, assess for himself whether the potential arc exposure hazard in front of his low voltage equipment is sufficiently simulated by:

• Either 4 kA Class 1 or 7 kA Class 2 value of Electrical Arc
• A duration of 0.5secs generated between the aluminium and copper electrodes
• The plaster box of specific dimensions
• A distance between the electrodes of 3cm
• A distance of 30cm between the electric arc and the person standing in front of the box

In reality many of these parameters will vary immensely in the real work environment and assumptions are commonly made that providing that the worker observes the parameters in the Box Test method, that Class 1 or Class 2 protective clothing will be sufficient. In reality, arc flash assessments show that these assumptions are not always true.

Arc Flash Studies and Risk Assessments

Arc Flash studies and risk assessments result in incident energy values at various working distances in front of the assumed arc flash for each piece of equipment on your site and each live working activity. These incident values are usually stated in units of cal/cm2

When choosing your protective clothing, a level of protection that exceeds the incident energy value (as a minimum) should be provided.

IEC61482-1-1/EN61482-1-1 Test Method – Open Arc Test

These are the test methods by which the protective performance of a fabric or garment can be assessed against the thermal hazards of an

Electric arc – we define this as ATPV (Arc Thermal Protective Value) and this is usually expressed in cal/cm2.

During the simulated testing undertaken in the laboratory, various test specimens of fabrics and garments are exposed to varying, directly measured incident energy levels caused by the electric arc. The levels of exposure are being selected during the testing as appropriate for obtaining the heat transfer measurements needed for a full Stoll curve differential analysis.

This ATPV Test Method enable garments to be tested and certified to an actual ATPV value. There is no Pass/Fail result when compared to the Box Test method and the meaningfulness and reliability of the ATPV results, in regards of second degree burn predictions, is also higher.

IEE1684 and NFPA 70E are the most commonly used tools and guidelines for calculating incident energy levels at various working distances in front of the assumed arc flash for each piece of equipment on your site and for each live working activity.

It is clear from the above that the Open Arc IEC61482-1-1 Test Method allows the wearer to specify confidently a protective garment with an ATPV value that is at least as high as the level established in their arc flash studies and risk assessments.

In an ideal scenario, garments could be certified to both test methods. However, in the absence of this, it would be considered best practice to choose a garment that is CE certified to the Open Arc Test Method IEC61482-1-1 as this is the only method which can provide an ATPV value for both the fabric and as a complete garment.

IEC61482 Performance Standards

This IEC document contains information regarding the performance requirements for clothing designed to protect against the thermal hazards of an electric arc. It also details information on both test method options – the Open Arc ATPV and the Box Test.

• Key design requirements for Arc Flash Garments
• Garments should have long sleeves
• No exposed external metal shall be permitted in the clothing. In internal metal and/or melting parts are used they shall be covered to the inside to avoid skin contact.
• All parts of the garment shall be made of arc thermal materials.
• Sewing threads must be made of inherent flame resistant fibres and shall not melt when tested at 260°C in accordance with the standard.
• The garment must have an ATPV of 4cal/cm2 (167,5 kJ/m2) as a minimum according to IEC61482-1-1 or Class 1 according to IEC61482-1-2.

For full details on all the design and test requirements please refer to the International Standard IEC61482-2 which is available from websites such as www.bsigroup.com

INHERENT FLAME-RETARDANCY

The term flame retardancy defines the reaction of a material to the impact of exposure to a flame. The phrase 'retardancy' is defined as slowing the continuation of flaming down or removing the propensity of a fabric to continue burning.

This can be achieved in two ways:

1) Melting technology, where the fibre or fabric is designed to melt rapidly at a temperature below that at which it would catch fire. Here the fabric forms a hole rapidly, thereby removing the fabric as a source of fuel. An example would be FR polyester: these fabrics hole very quickly and are perfect solutions for fabrics which do not cover a substrate that can be damaged (such as skin) or ignited (such as fillings in furnishings or bedding items), and so curtains and blinds can be made of such materials. It is further desirable to minimise any tendency to form molten or flaming droplets which could cause injury or carry a fire to the floor and ignite any coverings. Such fibres and fabrics CANNOT be used in PPE, for very obvious reasons.

2) Charring technology: here the fabric is designed to withstand the impact of naked flame and to form or maintain a barrier between flame and substrate (such as skin). This is the technology of Protal, and is the only realistic system to be used for PPE.

The 'barrier' technology can be achieved in two ways:-

(a) By topical application of a chemical treatment such as Proban or Pyrovatex. These can be of variable durability and there is always a danger of physical or solvent/aqueous erosion which will remove or diminish the effect. Such products are usually described as 'topical' treatments.

(b) By using an Inherent FR system. Here - and therefore can only really be applied to synthetic fibres - the FR technology is arrived at by incorporation of a flame-retardant substance into the raw material mix prior to extrusion or formation of the fibre. This ensures that the FR performance is locked into the basic textile fibre and is carried - without any diminution - through the various textile processes to finished fabric. The FR technology and therefore the performance and effect CANNOT be removed by physical erosion or by solvent or aqueous scouring/laundering.

The use of inherently flame-retardant (IFR) materials is always considered to be superior to that of topical treatment due to the likelihood of rubbing or washing away the effect, and also the impact the surface-only treatment may have on adverse skin reactions and any impact on the environment - no matter how 'durable'.