1. LABORATORY ELECTRICAL SAFETY Discussion topics: Electrical shock hazards Identifying hazards Research apparatus/ systems Proper emergency procedures Electricalfor Labs Rev.9-2000.ppt

2. Electrical Shock Hazards n Primary Hazards Electrical shock Flash burns n Secondary Hazards Fall from heights Injury from mechanical hazards Burns from electrical fire

4. Even Low Voltages Can Kill! Severity of shock depends on:  Current flowing through body  Duration of current flow through body  Path of current through body Ex: Hand contact w/ 120V (hand-to-hand pathway) I = 120V / 2000 ohms = 0.06 amperes = 60 mA (w/ wet hands, resistance is decreased)

5. Effects of Electrical Current Reference: Lawrence Livermore National Laboratory-- Document HS5220-W

6. Identifying Hazards: Outlets, Facility Wiring  Avoid overloading electrical outlets  Ensure to guard from exposed wiring or energized parts  Label all circuit-breaker switches  Leave at least 36” clearance in front of electrical panels  Ensure proper use of extension cords  NEVER repair/ modify facility electrical wiring Contact a qualified licensed electrician to perform work.

8. Identifying Hazards: Laboratory Equipment n Inspect tools/ equipment before use n Protective measures: 3-prong plugs Double insulation on handheld tools GFCI-type outlets n For any tools/ appliances that generate heat (soldering irons, hot plates, etc.), unplug when not in use

9. Research Apparatus/ Systems: Design Safety n Incorporate into the design: Protective devices Proper grounding Proper equipment enclosures Warning signs and labels n Systems safety design should be reviewed and approved by a qualified professional.

10. Research Apparatus/ Systems: Working with Electrical Systems Only knowledgeable and qualified persons shall work on electrical circuits/systems BASIC RULES:  Properly de-energize systems before starting work (should include lockout and tag)  Never work alone  Resist “hurry-up” pressures  Know local emergency procedures

11. Research Apparatus/ Systems: High Hazard Operations Personnel involved in a high hazard operation must use safe work procedures (a written safety procedure is required,SOP*). High hazard operations include, but are not limited to work involving:  Energized circuits  Higher voltage systems (> 240 V)  Capacitors (>10 J stored at > 50V) (*Standard Operating Procedure)

12. Response to Electrical Shock  Protect yourself  Call 9-911  Warn others of hazard  Shut off power immediately  Move victim to safety if safe to do so  Give necessary first aid IF TRAINED  Notify supervisor

13. Electrical Fire  Don’t use water or touch burning objects  If possible, unplug or turn off power  Activate fire alarm and call 9-911  If small fire and within your ability, use CO2 or ABC fire extinguisher to put out. Ensure that personnel have taken fire extinguisher training from EH&S-- Fire Safety Program (723- 0609)

14. Basic Electrical Safety Tips n Understand the hazards of your task. n Understand the equipment and circuit functions. n Make sure that you are trained to perform the task. n Don’t be afraid to ask for help.

15. Remember  Even low voltages will kill  Electricity does not discriminate-- Even the most experienced are at risk!  For more information, contact EH&S–  Occupational Health & Safety Program: 725-3209 lsteng@forsythe  Stanford Fire Marshal’s Office 723-0609 jleung@stanford.edu