Explosion-proof electrical equipment

Generally, it is more economical to prevent explosive atmospheres ia rooms than to try to provide explosion-proof electrical equipment. Personnel should never be allowed to work ia a ha2ardous atmosphere. Where such an atmosphere cannot be avoided through control of flammable Hquids, gases, and dusts, access to the area iavolved should be limited and the area segregated by hoods or special ventilation. Electrical equipment on open, outdoor stmctures more than 8 m above-ground usually is considered free from exposure to more than temporary, local explosive mixtures near leaks (86). 

Use only explosion-proof electrical equipment and spark-proof tools. 

Std. 3615 Explosion-proof Electrical Equipment Std. 3610 Electrical Intrinsically Safe Apparatus and Associated Apparatus for Use in Class I, II, and III, Division 1, Hazardous Locations... 

UL 58 An Investigation of Fifteen Flammable Gases or Vapors with Respect to Explosion-proof Electrical Equipment UL 58A An Investigation of Additional Flammable Gases or Vapors with Respect to Explosion-proof Electrical Equipment UL 58B An Investigation of Additional Flammable Gases or Vapors with Respect to Explosion-proof Electrical Equipment... 

More recently, the NFPA has used the MESG and the MIC ratio for classifying explosion-proof electrical equipment (NFPA 497 1997), and this approach can also be used for classilying flame arresters. In this method, NEC Class I combustible materials (vapors or gases) are divided into four groups ... 

NMAB. 1982. Classification of Gases, Liquids and Volatile Solids Relative to Explosion-Proof Electrical Equipment. Report NMAB 353-5. National Academy Press, Washington, DC (August 1982). 

EXPLOSION Finely dispersed particles form explosive mixtures in air. Prevent deposition of dust closed system, dust explosion-proof electrical equipment and lighting. Prevent build-up of electrostatic charges (e.g., by grounding). ... 

Laboratories working frequently with flammables, such as in extraction processes, may set aside a separate room for such work for maximum safety. Ideally, this room should have explosion-proof electrical equipment and special ventilation. Rigid work rules should be enforced, such as requiring workers to leave matches and lighters on a shelf outside before entering. Installation of conductive flooring should be considered, and steel tools should be prohibited at times when work is in progress. 

Designing so that spills would occur in a building, which would have explosion-proof electrical equipment and no other ignition sources... 

PERSONAL PROTECTION wear impervious gloves, footwear, and clothing wear splash-proof safety goggles above the flash point, use a closed system of local exhaust ventilation use explosion-proof electrical equipment wear positive pressure self-contained breathing apparatus maintain eyewash baths and safety showers in work area. 

PERSONAL PROTECTION Wear impervious protective clothing, including boots, chemical-resistant gloves, lab coat, apron or coveralls wear dust-proof safety goggles enclose operations and use local exhaust ventilation at site of chemical release use dust explosion-proof electrical equipment and lighting for extra personal protection, chemical protection suit including self-contained breathing apparatus is recommended. 

DISPOSAL AND STORAGE METHODS eollect powdered material and deposit in sealed containers store in tightly closed containers in a cool, well-ventilated area away from water and moisture separate from acids, alkalies, halogenated compounds, oxidizers, combustible materials use explosion-proof electrical equipment and fittings. 

DISPOSAL AND STORAGE METHODS manage whatever cannot be saved for recovery or recycling in an appropriate and approved waste disposal facility dispose of container and unused contents in accordance with federal, state and local requirements store in a cool, dry, well-ventilated location outside storage is preferred inside storage should be in a standard flammable liquid storage room or cabinet use explosion-proof electrical equipment and lighting ... 

PERSONAL PROTECTION wear impervious protective clothing, including boots, gloves, lab coat, apron or coveralls use chemical safety goggles, face shield, or eye protection in combination with breathing protection use positive pressure self-contained breathing apparatus in high vapor concentrations above 60°C, a closed system of local exhaust ventilation is preferred explosion-proof electrical equipment is recommended. 

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