| 231 THE RISK Protection against sparks, brief contact with fire and minimise the risk of electric shock from brief, accidental contact with electrical conductors. WELDING FLASH FIRE STATIC ELECTRICITY THE RISK An electrical charge caused by an imbalance of electrons on the surface of a material. EN 1149 standard specifies a test method for materials to be used in the production of protective clothing with electrostatic dissipation for preventing incendiary discharge. THE TEST EN 1149 - 1 Test method for measure of surface resistivity. EN 1149 - 3 Test method for measurement of charge decay. EN 1149 - 5 Material performance and design requirements. The NFPA® 2112 standard on Flame Resistant Clothing for Protection of Industrial Personnel Against Short-Duration Thermal Exposures from Fire. THE TEST Flame resistant fabrics must pass a comprehensive list of thermal tests, including the following: •ASTM F2700 – Heat Transfer Performance (HTP) Test This test is a measure of the unsteady state heat transfer properties of garment materials. •ASTM D6413 – Vertical Flammability (Flame Resistance) Test This test is used to determine how easily fabrics ignite and continue to burn once ignited. •Thermal Shrinkage Resistance Test This test measures a fabrics resistance to shrinkage when exposed to heat. •Heat Resistance Test This test measures how fabrics and components react to the high heat that could occur during a flash fire. •ASTM F1930-11 – Thermal Manikin Test This test provides an overall evaluation of how the fabric performs in a standardized coverall design after threesecond thermal exposure. •FTMS 191A – Thread melting resistance Thread used in flame resistant garments must withstand temperatures of up to 500°F. NFPA® 2112 FLASH FIRE EN ISO 11611 WELDING EN ISO 11611 Protective clothing for use in welding and allied processes THE TEST The standard specifies two classes with specific performance requirements. Class 1 is protection against less hazardous welding techniques and situations, causing lower levels of spatter and radiant heat. Class 2 is protection against more hazardous welding techniques and situations, causing higher levels of spatter and radiant heat. THE RISK Flash Fire is a sudden, intense fire which is short in duration but severe in potential danger. ELECTROSTATIC PROPERTIES EN 1149
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