3. INTRODUCTION
The fire hazard is the most pervasive, be it home, work
place or in the time of calamity.
The most devastating are the result of fire hazard
when a person’s clothing ignites.
Wearing fire resistant garment reduces the burn injury
and increasing the chances of surviving the flash fire.
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4. Should Meet The Following
Requirements
Flame resistance .
Fabric integrity .
Good thermal insulation .
Oil repellency .
Easy cleanibility .
Wearer acceptance .
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5. Flame Retardant Fibre
These fibres may be used solely or in blend form to arrive at
optimum performance and cost.
Chemically modified fibres and fabrics.
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6. Measure for high temperature
performance
A high temperature textile is define as a material that
can be used continuously at temperature over 200 c
without losing its major physical properties.
Another is LOI which is used to rate the flammability
of fibre.
LOI is %age oxygen level that must be present in
oxygen/nitrogen mixture of air before the fibre would
ignite and burn when exposed to flame.
Fibre with LOI in the mid 20s and above is considered
flame resistant.
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8. Aramid Fibres
Aramid fibres contains no flame retardant chamical i.e
phosphorus or halogen.
Nomex has good thermal stability and dose not melt.
Nomex especially suitable for firefighters.
Protective garments made from Nomex are also quit
comfortable.
Aamid fibre garment can be laundered and dry
cleaned without any loss of flame retardency.
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9. Polybenzimidazole
PBI does not burn in air.
PBI fabrics remain stable and maintain integrity.
PBI retains its strength well when tested during
exposure at elevated temperature.
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10. Kermal
Heat resistant and inherently non flammable fibres.
It is non melting and non shrinking organic fibre
which offer light weight and soft hand.
It is high price but high performance fibre
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11. Polyphenylene Sulphide fibre
It is classified as non flammable .
LOI is 34-35 .
It dose not support combustion under normal
atmospheric condition.
In addition, its chemical resistance and ability to
retain its physical properties under extremely adverse
condition make it valuable for protective clothing.
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12. Polyacrylate fibres
It neither burns nor melts.
It emits virtually no smoke or toxic gases.
LOI is 43 .
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13. Semicarbon fibres
These fibres are produced by partial carbonization of
PAN fibres, for e.g Celiox and Panox .
Excellent heat resistance .
Comfort to wear.
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14. Chemically Modified Fibres And
Fabric
Special treatment are given to fibre and fabric to make
them fire resistant , for e.g :-
At the polymerization stage.
By using some modifier.
By surface modification .
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15. Protective Clothing
Firefighter protective clothing limit the dissipation of
body metabolic heat.
So protective garment has several layers :-
Outer shell .
Vapour barrier .
Inner liner .
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16. Design Features
Coat and jacket .
Collar .
Front closure .
Coverall or pants .
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17. Effect Of Fabric Construction
In hot environment or direct flame ( 150-250 g/m² )
For full installations (250-320 g/m² )
For workshop (320-400 g/m² )
Against molten metal (900 g/m² )
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18. Current ASTM Standards
TPP, NFPA 2000, (the former ASTM D 4108), ASTM F
2700-08, ISO 9151,
ISO 17492, CGSB
ASTM F955 -07 : Molten Substances, ISO 9150, ISO
9185/BS373
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19. ASTM standard
ASTM F 2700‐08, Standard Test Method for Unsteady‐State Heat
Transfer
Evaluation of Flame Resistant Materials for Clothing with
Continuous Heating
(NFPA 1971 Thermal Protective Performance (TPP) test)
ASTM F1939 ‐08, Standard Test Method for Radiant Heat
Resistance of Flame Resistant Clothing Materials with
Continuous Heating
ASTM F 1060 ‐08, Test Method for Thermal Protective
Performance for Protective Clothing for Hot Surface Contact
ASTM 2701 – 08 Standard Test Method for Evaluating Heat
Transfer through Materials for Protective Clothing Upon Contact
with a Hot Liquid Splash
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21. Chemical Protection
Protective clothing cannot be made generic for all chemical
applications, since chemicals vary in most cases and a particular
CPC can protect only against a limited number of specific
chemicals.
Important considerations in designing chemical protective
clothing are
The amount of chemical permeation.
Breakthrough time for penetration.
Liquid repellency.
Physical properties of the CPC in specific chemical conditions.
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22. c
Chemical protective clothing can be categorized as
encapsulating or non-encapsulating based on the style of
wearing the clothing.
CPC is rated for four levels of protection, levels A, B, C and
D from highest protection to normal protection.
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24. Requirements
Chemical Protective Clothing Should Resist :
Permeation , Degradation, Penetration.
Durability
Flexibility
Temperature Resistance
Service Life
Clean Ability
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25. Permeation
Permeation is the diffusion of a chemical on a
molecular basis through chemical protective clothing.
This movement of the chemical through the protective
material may not be readily noticeable because it
occurs on a molecular or microscopic level.
The time it takes the chemical to pass through the
protective material until it is first detected by an
analytical instrument is called the breakthrough time.
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27. Degradation
The change in the physical properties of the material
as a result of adverse effects of the chemical is called
degradation.
Physical properties may include material
weight, dimensions, tensile strength, hardness.
The most common observations of material
degradation are Swelling, Loss of Strength or
Deterioration.
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29. Penetration
Penetration is defined as `the flow of chemical
through closures, porous materials, seams, and
pinholes and other imperfection in a protective
clothing material on a non-molecular level.
This definition is intended to accommodate both
liquids and gases.
Penetration of chemicals may take place through
Zippers, Seams or Imperfections in Protective Clothing
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31. Textile Materials
Ordinary textile materials are generally not considered suitable for protection
against chemicals, however special non-coated textile materials are used for a
variety of applications involving particulates and light liquid spray from
relatively non-hazardous chemicals.
Though woven textiles are not often found in chemical protective clothing, very
tightly woven, repellent-treated fabrics can provide some very low minimum
protection against liquid exposure.
More common are nonwoven fabrics that have demonstrated barrier
performance against particles and repellency of liquids.
Two predominant examples of non- woven fabrics are flashspun polyethylene
(Tyvek) and spunbond/ meltbown/ spunbond (SMS) polypropylene
(Kleenguard).
These textiles are used because of their relatively low cost and because the
materials provide a structure of microfibers that filter out dry particulates and
many water-based liquids.
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32. Flash Spun Polyethylene
Made from very fine, high-density polyethylene fibers, lightweight
yet strong; vapor permeable, yet water- and chemical-resistant, as
well as puncture-, tear- and abrasion-resistant.
Tyvek® is formed by a fully integrated process using continuous
and very fine fibers of 100% high-density polyethylene that are
randomly distributed and no directional. These fibers are first
flash-spun, then laid as a web on a moving bed before being
bonded together by heat and pressure - without the use of
binders.
Extensive Temperature Range, Excellent Dimensional Stability: -
73°C (132°C). 32
33. SMS Polypropylene
Breathable fabric multilayered laminate.
The two outer spun bond layers are made of randomly deposited
15 – 20 micron diameter continuous polypropylene fibres which
provide cloth-like comfort while also offering fabric
strength, durability and abrasion resistance.
The inner melt blown layer provides a filter barrier and is typically
comprised of 1-3 micron diameter polypropylene fibres.
The advantage of melt blown as the barrier layer is that it is
permeable to both air and moisture vapour, meaning that both air
and sweat vapour can pass through the garment to keep the skin
cool and the wearer more comfortable in hot working
environments.
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34. Unsupported Rubber and Plastic
Materials
Normally, chemical protective clothing materials include
supporting textile fabrics to provide strength.
However, there are some CPC materials that do not include a
fabric substrate. The rubber material or plastic is thick enough to
provide sufficient strength for clothing use.
Examples of polymers used in these materials are polyvinyl
chloride and chlorinated polyethylene.
Because the materials are continuous, they offer a barrier to
liquids and can be used in the construction of CPC intended for
protection against liquids and gases.
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35. Micro Porous Film-Based
Materials
Microporous films have millions of microscopic pores per square
inch of the film structure.
In most cases, the pores are irregularly shaped with tortuous
paths through the film.
This material feature makes the film `breathable' .
The microporous films are generally glued or laminated to
woven or nonwoven fabrics for physical support.
Owing to their physical structure, these fabrics provide barrier
performance against liquids but not gases. 35
36. Adsorbent-Based Materials
These materials include adsorbents, such as activated
charcoal or other sorbent materials.
Activated Carbon : Activated carbon in very fine powder
or granular form is useful to purify both water and air.
Activated carbon has particular affinity to organic materials
such as solvents used in printing inks and common coatings.
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37. Development of Chemical
Protective Clothing:
The chemical protective clothing is formed by five layers, the
outer shell made of polyester as it has low absorption of 2%
and it provides a good strength to the fabric and polyester
has a good resistance to lab grade chemicals.
The inner layer is made up of cotton fabric as it gives good
absorbency and comfort.
The middle layer comprises of cotton non woven
sandwiched with activated carbon.
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38. Some other fabrics
Coated nylon or polyester fabric. Coated with butyl
rubber having base fabric varies between 250-500g/m².
Multilayer sandwiched type :-
Polymide or polyester is sandwiched between weldable
pollyolefin films.
Weight 100-150 g/m²
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39. c
The conventional chemical protective clothing was
based on embedding activated carbon using adhesives
and polyurethane foam with a activated carbon load of
120 – 160 GSM.
These fabrics had low comfort properties of air
permeability and thermal comfort causing stress to the
wearer.
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42. Garment Design Features
The type and location of Seams.
The type, length, and location of the closure system(s).
The type and characteristics of visors or face shields, if
integrated into garments.
The design of interface areas with other chemical
protective clothing or equipment.
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45. Closure Systems
Closures are typically the `weak' link in the chemical
protective clothing barrier.
The simplest closures are zippers or a series of snaps.
CPC designs use storm flaps to cover the zipper or snaps
Liquid-repellent zippers are conventional zippers that
use rubber or plastic coated tape instead of woven cloth
on the sides of the zipper and that have a special chain
(teeth) that are coated to limit liquid penetration.
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47. Garment Visors
Visors are generally incorporated into suits to offer chemical
barrier protection for the head and face area. In general, the visor
is constructed from a material that provides clear undistorted
vision as well as chemical resistance.
The principal materials used in visor construction are polyvinyl
chloride, polycarbonate, and polymethacrylate.
Since the visor material must provide optical qualities, only
transparent materials can be chosen as visors.
When greater chemical resistance is required, the visor be made
of a composite material that includes fluorinated ethylene
propylene (FEP) laminated to PVC.
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49. Level A
Level A should be worn when the highest level of respiratory, skin, and
eye protection is required.
Level A is used when:
Conditions are unknown.
The hazardous substance has been identified and requires the highest
level of protection for skin, eyes, and respiratory system.
Operations are being conducted in confined, poorly ventilated areas.
Work function involves a high potential for splash, immersion, or
exposure to unexpected skin hazards .
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51. Level B
Self-contained breathing apparatus, Chemical protective
clothing, gloves, and hard hat. Should be selected when the highest level
of respiratory protected is needed and some degree of skin protection is
required.
Level B is the minimum recommendation for initial site entry.
Level B protection is used when:
Air contaminants are unknown.
Air contaminants have been identified and the criteria for using APRs
are not met.
The atmosphere contains less than 19.5% oxygen.
Direct contact does not pose a severe skin hazard.
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53. Level C
Level C should be selected when types of airborne contaminants
are known, the concentrations are measured and the criteria for
using air-purifying respirators (APRs) are met.
Level C protection is used when:
Criteria for the use of APRs are met.
Air contaminants have been identified and concentrations
measured.
Direct contact does not pose a skin hazard.
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55. Level D
Level D should not be worn on any site with respiratory or skin
hazards.
Level D is primarily a work uniform providing minimal protection.
Level D protection is worn when:
Atmosphere contains no known hazards.
Work functions precludes the potential for unexpected exposure
to hazardous levels of any substances.
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