Lightning Strikes: Protecting People, Events and Property
Lightning is a major cause of storm-related deaths and property damage, though it's often overlooked as an occupational hazard. It becomes a larger scale concern when people gather for outdoor events. The months of June, July and August are peak months for lightning activity in the U.S., so now is the time to prepare.
Protect Outdoor Workers
While all outdoor workers are vulnerable to severe weather, employees are most vulnerable to lightning when they are in open spaces or working adjacent to tall objects that attract lightning strikes (tall trees, hilltops, utility poles, cell phone towers, cranes, ladders, scaffolding). Municipal workers are also uniquely at risk because of the varied outdoor functions of their jobs; a fact sheet from OSHA and the National Oceanic and Atmospheric Administration indicates some of the occupations most likely to be impacted by lightning include construction, agriculture, telecommunications, pool/aquatics and landscaping. You should have a plan in place to protect outdoor workers from lightning, but here are some general guidelines:
- Outdoor workers should monitor weather conditions during storm season and plan their work accordingly. If storms are in the forecast, don't start any jobs that can't be stopped quickly.
- In the event of storms, seek shelter in a fully enclosed building with plumbing and electrical wiring if possible. Stay inside until 30 minutes after the last signs of thunder.
- If an enclosed building isn't available, shelter in a hard-topped vehicle with the windows rolled up. For long-term projects without a safe building nearby, consider other options for good outdoor lightning shelters.
Protect Events and Attendees
Lightning is one of the most common types of severe weather to impact outdoor events. Put together a plan in advance to ensure your employees know what to do to keep event attendees safe.
- Designate weather watchers and decision makers who have the authority to delay or cancel the event if needed.
- Determine criteria in advance to help guide decisions about weather response.
- Create a list of safe shelter locations for each field or site where events are held. Post informational signs or flyers with shelter information, and ensure you can effectively communicate weather announcements.
- Apply the 30/30 rule: When you see lightning, count the time until you hear thunder. If it's 30 seconds or less, suspend outdoor activities and seek shelter. Wait 30 minutes or more after hearing the last thunder before resuming an activity or returning outdoors.
Lightning strikes cause approximately 1,800 non-residential building fires and more than $1 billion in property damage every year, so it makes sense to be proactive about preventing lightning damage. If you don't already have lightning protection in place, consider installing a lightning protection system which will guard against damage to the actual building as well as what's inside.
A protection system often includes lightning rods, which conduct the energy from a lightning strike safely to the ground where the charge dissipates. Inside, surge protection devices help protect electrical equipment from lightning and electrical surges.