Lightning strikes can severely injure or kill workers whose jobs involve working outdoors. Lightning is often overlooked as an occupational hazard but employers need awareness about lightning hazards to ensure their workers’ safety. This toolbox talk provides employers and workers at outdoor worksites with lightning safety recommendations from the Occupational Safety and Health Administration (OSHA) and the National Oceanic and Atmospheric Administration (NOAA).
KNOW THE FACTS:
- Lightning heat exceeds 50,000 degrees F (3 times hotter than the surface of the sun).
- Lightning bolts travel at 90,000 miles/second.
- Lightning bolts are 1-2 inches wide.
- Being struck by lightning is the second most frequent cause of weather-related deaths.
The likelihood of being struck by lightning varies depending on the situation. About 40% of lightning strikes occur in elevated work areas and open fields. Another 23% happen under trees, while 14% occur during boating or swimming. Golf accounts for 5% of lightning strikes, as does the use of heavy machinery. Lastly, 4% of lightning strikes happen while using a telephone. Regarding gender, 84% of lightning strike victims are men, while 16% are women.
Lightning is a dangerous natural force. Annually in the United States, cloud-to-ground lightning occurs 20 to 25 million times and over 300 people are struck by lightning. About 50 people on average are killed by lightning strikes every year and many more suffer permanent disabilities.
FIVE WAYS LIGHTNING CAN KILL:
- A direct strike
- A side flash
- Conducted current
- Step voltage
- Secondary effects
WARNING SIGNS OF A STRIKE:
- Other visibly close strikes
- Skin tingling
- Hair standing on its ends
- Hearing crackling noises
- Hearing loud thunder
THE LIGHTENING-SAFE POSITION (OUTSIDE):
- Crouch on the ground
- Weight on the balls of your feet
- Heels together
- Head lowered
- Eyes closed
- Ears covered
- Never lie flat on the ground
FIRST AID FOR LIGHTNING VICTIMS
- Injured persons do not carry an electrical charge; apply first-aid (if trained) & call 911 (Outside)
- Administer first aid as quickly as possible
- If unconscious: Check breathing and pulse
- Person has a pulse but not breathing: Begin CPR
- Check for other injuries
HOW TO MONITOR FOR LIGHTNING:
- Criteria: Lightning at 30 miles or 30 minutes out or last strike.
Actions: Notify personnel of increased lightning hazard. Prepare to cease unnecessary outdoor activity. Have nonessential personnel find shelter. - Criteria: Lightning at 15 miles or thunder heard by personnel, no lightning flash observed and the assigned competent person is activity tracking on radio or an app.
Actions: Secure outdoor equipment. Cease outdoor activity other than securing equipment and critical tasks. Employees not actively engaged in securing activities should move to designated lightning shelter. - Criteria: Lightning at 10 miles or lightning observed.
Actions: Immediately STOP Outdoor Activity. Abandon efforts to secure equipment if not completed. All personnel take cover in designated shelter. If none is available, you can utilize a hardtop automobile as secondary option only. Personnel on foot should find low risk locations and separate or disperse.
SUMMARY
Employers should recognize lightning as an occupational hazard. Supervisors and workers at outdoor worksites should take lightning safety seriously. Workers whose jobs involve working outdoors, in elevated or open places, on or near tall objects or near explosives or conductive materials (e.g., metal) have significant exposure to lightning risks. Worker activities at higher risk for lightning hazards include: roofing, aerial lifts, scaffolding, Electrical, rebar, cranes and tops of walls.
During storms or high winds, OSHA prohibits: • working on or from scaffolds (29 CFR 1926.451(f)(12)); • working on crane hoists (29 CFR 1926.1431(k)(8)); • working on top of walls (29 CFR 1926.854(c)); and • General Duty Clause, Section 5(a)(1). www.osha.gov and wrn.feedback@noaa.gov.
