Although it may often be overlooked as an occupational hazard, lightning poses a serious risk, especially within the maritime industry. Although most facilities are fortunate enough never to have a lightning strike-related injury or fatality, you should take precautions to prevent them from occurring, especially if your facility is on or close to the water.
According to OSHA, cloud-to-ground lightning occurs 20 to 25 million times annually in the U.S., striking more than 300 people. In the past 30 years, an average of 50 people each year have been killed by lightning strikes, and many more suffer permanent disabilities.
Lightning Strike Facts
Lightning is a giant spark of electricity in the atmosphere between clouds or between a cloud and the ground. Although most lightning occurs in the summer, it can strike at any time of the year. Surprisingly, lightning can strike outside of the heaviest thunderstorm areas and up to 10 miles from any rainfall. Many lightning victims are caught outside during a storm because they did not act quickly to get to a safe place, or they go back outside too soon after a storm has passed. It is recommended to stay inside a safe building or vehicle for at least 30 minutes after you hear the last thunder; it may seem like a considerable amount of time, but it is necessary to be safe.
As soon as you hear a distant rumble of thunder, it is recommended to get to a safe place immediately as thunderstorms ALWAYS include lightning. Lightning always takes the path of least resistance to the ground; therefore, tall isolated objects such as a crane boom (specific to the maritime industry) is an ideal conductor for electricity. Lightning warning or detection systems are available; however, the best lightning warning system may be to watch the sky for storms developing overhead or nearby and get to a safe place before the first lightning strike. As a rule of thumb, consider the saying, “When thunder roars, go indoors!”
Lightning Strike Risk/Injuries
A common misunderstanding about lightning victims is that they carry an electrical charge. They may need first aid immediately, and you should never hesitate or be scared to help.
Only about 10% of lightning strikes result in fatal injuries. Some lighting strike victims may not show signs of injury while others may not even remember what happened. Lightning strikes are known to cause the following injuries:
- Keraunoparalysis, a temporary paralysis unique to lightning strikes
- Blunt trauma (crush injuries) broken bones/dislocations to the skull and cervical spine (neck)
- Head injury/loss of consciousness
- Cardiac arrest/heart damage
- Ruptured eardrum and/or hearing loss
- Eye injuries
- Nervous system damage
If you are providing assistance to lightning victims, consider the following steps:
- Call 911 for emergency medical services.
- Start CPR (if you are trained/qualified) immediately on any person who is not breathing and does not have a pulse. Instructions for doing CPR can be given over the phone by the 911 dispatch center.
- Use an Automatic External Defibrillator (AED) if one is available which can be life-saving.
- If possible, move the victim to a safer place, but don’t become a victim yourself. Lightning CAN strike twice.
Any person suspected of being struck by lightning should be evaluated in a hospital's emergency department, even if injuries are not obvious.
Lightning Strike Injury Prevention
It’s critical that employers, supervisors, and employees understand the dangers of lightning and have a lightning safety plan. Supervisors and workers should know in advance where a worksite’s safe shelters are and the time it takes to reach them. It only takes one strike to change your life forever.
Before beginning any outdoor work, employers and supervisors should check local television, radio, and Internet weather reports, forecasts, and emergency notifications for all weather hazards and severe weather activity. OSHA recommends that employers consider rescheduling jobs to avoid workers being caught outside in hazardous weather conditions. Darkening clouds and increasing wind speeds are an indication of developing thunderstorms. While no place outside is safe when a thunderstorm is in the area, here are helpful recommendations to consider if there are signs of approaching thunderstorms and workers are outside:
- Avoid being outside in open spaces and seek shelter immediately.
- Avoid isolated tall trees, hilltops, utility poles, cell phone towers, cranes, large equipment, ladders, scaffolding, or rooftops. Lightning tends to strike the tall objects.
- Stay away from metal conductors such as wires or fences and do not carry or hold tall metal objects during thunderstorms. Metal does not attract lightning, but lightning can travel long distances through it.
- If you are with a group of people, spread out. Although this may increase the chance of someone getting struck, it tends to prevent multiple casualties and increases the chances that there is someone who can help lightning strikes another person.
- Avoid water, and immediately get out of and away from bodies of water as they are great conductors of electricity.
- Avoid sheds, picnic shelters, tents or covered porches as they do NOT adequately protect you from lightning.
- If safe building structures are not accessible, employers should guide workers to hard-topped metal vehicles as they can provide suitable shelter. All windows must be closed and anything metal that is connected to the vehicle must not be touched.
Indoors is the safest place during a thunderstorm – specifically, fully enclosed buildings with electrical wiring and plumbing. Do not use corded phones, except in an emergency. If applicable, avoid windows, doors, and porches. Lightning travels through the wiring and plumbing if a building is struck. Don’t take a bath or shower, or wash dishes during a storm. It is also recommended to not lie on concrete floors or lean against concrete walls (which may have metal bars inside).
Developing a Lightning Safety Plan
Here are some specific safety protocols on the dangers of lightning to include when developing a lightning safety plan:
- Inform supervisors and workers to act immediately after hearing thunder, seeing lightning, or perceiving any other warning signs of approaching thunderstorms.
- Indicate how workers receive notification about lightning safety warnings.
- Identify locations and requirements for safe shelters.
- Indicate response times necessary for all workers to reach safe shelters.
- Specify approaches for determining when to suspend outdoor work activities, and when to resume outdoor work activities.
- Account for the time required to evacuate customers and members of the public, and the time needed for workers to reach safety.
- Post information about lightning safety at outdoor worksites.
It may also be helpful to post lightning safety signage around outdoor worksites. Here are some examples:
Are You Prepared?
Consider how lightning could affect your workplace. Do you have adequate measures in place to control lightning hazard exposures? If not, a formal lightning safety plan should be developed to protect employees from lightning strikes. If you have any questions or would like additional information on lightning safety, contact us.
APPLICABLE OSHA STANDARDS
Under the General Duty Clause, Section 5(a)(1) of the Occupational Safety and Health Act of 1970 (OSH Act), employers are required to provide their employees with a place of employment that “is free from recognizable hazards that are causing or likely to cause death or serious harm to employees.” These hazards may include lightning hazards that can cause death or serious bodily harm.
NOAA-National Weather Service-Lightning Safety
eMedicineHealth - Lightning Strike
OSHA/NOAA Fact Sheet - Lightning Safety When Working Outdoors (OSHA FS 3863- 2016)