The Other Hazard of Electricity. Larren Elliott Ph.D. Lindsay Polic, CSP, REHS

Transcription

1 The Other Hazard of Electricity Larren Elliott Ph.D. Lindsay Polic, CSP, REHS

2 Presenters Larren Elliott Ph.D. EORM Electrical Safety Service Partner 45 years practical and hands-on industrial experience Electrician Trainer Electrical Inspector s Exam certified by the International Association of Electrical Inspectors (IAEI) Lindsay Polic, CSP, REHS Principal Consultant with EORM 12 years of EH&S experience, both consulting and industry Comprehensive EH&S audits Program development and training Process Safety Management (PSM) and environmental Risk Management Plan (RMP) gap assessments 2013 Environmental and Occupational Risk Management, Inc. 2

3 About EORM History Founded in 1990 by Environmental, Health and Safety (EHS) managers to offer comprehensive EHS management and technical consulting services to the high tech industry In late 90s, successfully diversified our client base into multiple regional and vertical markets across the US and beyond Today 100 employees supporting 350 customers from 5 regional offices in US; HQ in San Jose, CA Multidisciplinary EHS and Sustainability consulting team Well-established partners allow for cost-effective and highly responsive international support ISO and OHSAS Certified EORM Confidential -- Not for Distribution 2013 Environmental and Occupational Risk Management, Inc. 3

4 Key Service Areas Industrial Hygiene Safety EHS and Sustainability Outsourcing/ Shared Services Ergonomics Process Safety EHS Auditing and Management Systems Environmental Compliance Business Continuity Planning Corporate Sustainability EORM Confidential -- Not for Distribution 2013 Environmental and Occupational Risk Management, Inc. 4

5 What We ll Uncover Today Hazards and Risk Identification What We ll Uncover Today What is an arc flash? What are the dangers of an arc flash? How can the hazards be calculated? How can the hazards be reduced? What are the typical PPE requirements? Questions and answers 2013 Environmental and Occupational Risk Management, Inc. 5

6 The Hazards of Electricity The first hazard of electricity that most people think about is: SHOCK 2013 Environmental and Occupational Risk Management, Inc. 6

7 Typical Effects of Electricity on Adults ma = 1/1,000 of an ampere Current Results <1 ma None 1 ma Perception threshold 1-3 ma Mild sensation 3-10 ma Painful sensation 10 ma Paralysis threshold of arms. Cannot release handgrip. 30 ma Respiratory paralysis (stoppage of breathing) 75 ma Fibrillation threshold. May produce a.5% uncoordinated heart action. 250 ma Fibrillation threshold. May produce a 99.5% uncoordinated heart action. 4 A Heart paralysis threshold. Heart stops for duration of current passage. For short shocks may restart on interruption of current. >5 A Tissue burning. Usually not fatal unless vital organs are burned Environmental and Occupational Risk Management, Inc. 7

8 The Physiological Effects of Electric Shock 2013 Environmental and Occupational Risk Management, Inc. 8

9 Body Resistance 500 Ω 500 Ω 100 Ω 500 Ω 500 Ω E = I R I E 2 I R P R P E 2 E R P I E R I R E R P I 2 E = 50 ma x 1100 Ω E 50 Volts P I 2 E P P R E I 2013 Environmental and Occupational Risk Management, Inc. 9

10 The Hazards of Electricity The other hazard of electricity is ARC 2013 Environmental and Occupational Risk Management, Inc. 10

11 Arc Flash Defined A dangerous condition associated with the release of energy caused by an electric arc An arc is produced by the flow of electrical current through ionized air after an initial flashover or short circuit Arc Flash can result from inserting a tool in the wrong place or dropping a tool into a circuit breaker or service area Arc Flash can also result from an equipment failure Any of these conditions may cause a phase-to-ground and/or a phase-to-phase electrical short circuit fault 2013 Environmental and Occupational Risk Management, Inc. 11

12 Arcing Fault Events The temperature of an arc is approximately 20,000oC (35,500oF) That s four times the temperature of the surface of our Sun! If the temperature of your skin gets greater than 99oC (210oF) for more than a 1/10th of a second you will receive a severe burn onset of a second degree burn If your skin receives more than 5 joules/cm2 (1.2 cal/cm2) you will receive a severe burn A candle flame produces around 4.2 joules/cm2 (1 cal/cm2) 2013 Environmental and Occupational Risk Management, Inc. 12

13 Arc Flash Effects Burns from intense heat Trauma from blast pressure Toxic gases from vaporized metal Sprayed molten metal droplets Hearing damage from sound pressure wave Eye damage 2013 Environmental and Occupational Risk Management, Inc. 13

14 Residential 120 Volt Breaker Failure This is why you want to always wear a leather glove when opening or closing a breaker! First degree burns 2013 Environmental and Occupational Risk Management, Inc. 14

15 The result of plugging in a knowingly bad 220 Volt clothes dryer. All fingers and thumbs of both hands had to be removed Environmental and Occupational Risk Management, Inc. 15

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21 Hierarchy of Effective Hazard Control 2013 Environmental and Occupational Risk Management, Inc. 21

22 Arc Flash Standards Arc flash hazard studies have emerged as an engineering service centered around two primary national standards: NFPA 70E-12 Standard for electrical Safety in the Workplace and CSA Z Workplace Electrical Safety recognize many different calculation methods to determine the hazards associated with an arc flash The primary method that is used by a majority of software vendors is IEEE 1584, Guide for Performing Arc Flash Hazard Calculations, Once the arc hazard has been quantified then NFPA 70E and CSA Z462 can be used to determine the PPE requirements International Council Directive 89/686/EEC in Article 100a requires that when related to Personal Protective Equipment, the measured value of hazard must match a measured value of protection. The IEC has yet to provide technical direction on arc hazard quantification 2013 Environmental and Occupational Risk Management, Inc. 22

23 NFPA 70E 2012 (9TH Edition) First edition 1979 Three chapters Safety-Related Work Practices Safety-Related Maintenance Requirements Safety Requirements for Special Equipment 16 Annexes 2013 Environmental and Occupational Risk Management, Inc. 23

24 Elements of Arc Flash Safety Defined responsibilities Arc Flash Hazard Analysis Calculation of the amount of arc flash hazard Warning labels on equipment Training Personal protective equipment Tools for safe work 2013 Environmental and Occupational Risk Management, Inc. 24

25 Responsibilities A workplace free from known and recognized hazards that could cause death or severe injury. Employer will provide: PPE Training Labeling Insulated tools Lock out/tag out devices Employee will: Follow safe work practices Use appropriate voltage rated (insulated) tools Wear PPE when required 2013 Environmental and Occupational Risk Management, Inc. 25

26 Elements of Arc Flash Safety Determine the flash protection boundary onset of a second degree burn (5 joules/cm2 or 1.2 cal/cm2) Arc flash hazard and flash protection boundary varies with: Type of equipment and configuration Available short circuit fault current Voltage Predicted fault duration protective devices upstream of the arcing fault and their settings Distance in feet for onset of a second degree burn Applied nominal voltage Available fault current in amperes Time in seconds fault current flows D C = (2.65 x MVA bf x t) ½ 2013 Environmental and Occupational Risk Management, Inc. 26

27 Engineering & Maintenance The hazards associated with arc flash must be predictable and when possible reduced through: Performance testing of breakers down to the point in the electrical system where there is no longer a hazard A selective coordination study to determine proper over current protection device reaction time An Arc Flash study Labeling of electrical equipment that has the capacity to produce an arc (e.g., switchboards, panel boards, motor control centers) with appropriate arc flash labels that communicate the presence of a shock or arc flash hazard and that personal protective equipment is required to work within the documented flash protection boundary 2013 Environmental and Occupational Risk Management, Inc. 27

28 Engineering Controls 2013 Environmental and Occupational Risk Management, Inc. 28

29 Flash Protection Boundary Linear distance from exposed live parts within which a person could receive second degree burns resulting from an arc flash 2013 Environmental and Occupational Risk Management, Inc. 29

30 Administrative Controls Relationships with Contractors Host Employer must: Inform contract employer of known hazards Report observed contract employer-related violations Contract Employer Responsibilities: Ensure that each employee is instructed in the hazards and follows the standards and work rules required by the host employer Advise host employer of unique or unanticipated hazards not reported by host employer Measures the contractor took to correct any violations reported by host employer This meeting must be documented 2013 Environmental and Occupational Risk Management, Inc. 30

31 Administrative Controls Training Requirements Document that Qualified Persons have demonstrated that they are qualified to work on the specific equipment Employees exposed to shock hazards and first responders must be trained in: Methods of release First aid including annual certification in CPR and AED use Document conformance assessment that each employee is complying with safety-related work practices required by NFPA 70E 2013 Environmental and Occupational Risk Management, Inc. 31

32 Administrative Controls LOTO and other Job Requirements Individual Control has been eliminated from NFPA 70E. Verification of deenergization by phase-to-ground and phase to phase Employer must provide up-to-date drawings, diagrams, or identification tags Documented pre-job briefings Documented risk assessment procedure that includes hazard analysis, risk estimation, and risk evaluation procedures An Energized Electrical Repair Work procedure and permit 2013 Environmental and Occupational Risk Management, Inc. 32

33 Labeling Switchboards, panel boards, industrial controls, etc. that require examination, adjustment, or maintenance while energized shall be labeled. Labels shall be designed to warn of potential arc flash hazards 2013 Environmental and Occupational Risk Management, Inc. 33

34 Arc/Flash Protection Face Shield Hard Hat Liners Arc/Flash Suits Beard Cover & Hair Net Balaclava Arc/Flash Hood 2013 Environmental and Occupational Risk Management, Inc. 34

35 Typical Protective Clothing Hazard/Risk Category Clothing Description 0 Non-melting, flammable material with fabric weight of at least 4.5 oz/yd 2 Required Minimum Clothing Arc Rating [J/cm 2 (cal/cm 2 )] Not applicable 1 Arc-rated shirt + pants or Arc-rated coveralls (4) 2 Arc-rated shirt + pants or Arc-rated coveralls (8) 3 Arc-rated flash suit and hood or a tested layered system meeting the required minimum rating (25) 4 Arc-rated flash suit and hood (40) 2013 Environmental and Occupational Risk Management, Inc. 35

36 Typical PPE Requirements Hazard/Risk Category Eye protection, ear canal inserts, long sleeve shirt and pants 0 Arc rated clothing Face & Head Protection 1 2 Flash Suit Hood Environmental and Occupational Risk Management, Inc. 36

37 HRC-1 HRC-2 HRC-3 HRC-4 10 cal/cm 2 Hands must have more AR protection 2013 Environmental and Occupational Risk Management, Inc. 37

38 Cleanroom AR Clothing As well as Cintas and Oberon 2013 Environmental and Occupational Risk Management, Inc. 38

39 ISO cleanroom standards Class maximum particles/m³ 0.1 µm 0.2 µm 0.3 µm 0.5 µm 1 µm 5 µm FED STD 209E equivalent ISO ISO ISO 3 1, Class 1 ISO 4 10,000 2,370 1, Class 10 ISO 5 100,000 23,700 10,200 3, Class 100 ISO , ,000 35,200 8, Class 1,000 ISO ,020, ,000 83,200 2,930 Class 10,000 ISO ,520, ,000 29,300 Class 100,000 ISO ,200,000 8,320, ,000 Room air 2013 Environmental and Occupational Risk Management, Inc. 39

40 Layering of arc-rated clothing can increase rating only when tested as a multilayer test sample 2013 Environmental and Occupational Risk Management, Inc. 40

41 Voltage Rated Insulated Tools When repair work must be done on energized equipment, tools must meet the ASTM F 1505 standard 2013 Environmental and Occupational Risk Management, Inc. 41

42 Thank you! Contact Lindsay Polic with any questions Lindsay Polic Principal Consultant View the recorded webinar at See for more information 2013 Environmental and Occupational Risk Management, Inc. 42