One may encounter many different types of electric vehicles on a job site or at the workplace—e.g., forklifts, pallet trucks, golf carts and even Segways. They all run on batteries that must be periodically recharged, a process that has many safety considerations. It isn’t just an issue for workplace electric vehicles either. It is important to remember that, with the popularization of electric cars, the need for careful battery recharging will become even more far-reaching and will touch those not familiar with electrical safety.
Electric vehicles are commonly used indoors because they are quieter and less polluting than their combustion-engine counterparts. While virtually eliminating the carbon monoxide poisoning hazard, this type of vehicle presents a different set of dangers. The main hazard stems from the battery that powers these vehicles. To help lessen injuries stemming from exposure or misoperation, the Occupational Safety and Health Administration (OSHA) offers guidelines that include establishing a designated area for battery charging. A properly equipped battery-charging area includes the following:
• “No Smoking” signs posted appropriately
• Adequate fire protection, including a dry-chemical, carbon-dioxide or foam fire extinguisher.
• Enough readily available water for flushing and neutralizing any electrolyte that may spill or leak from a battery
• An eyewash station capable of providing a 15-minute flow of water. For large installations, there should be a plumbed drench shower in addition to the eyewash.
• A means of calling for help in case of an emergency
• Ventilation sufficient to prevent the buildup of hydrogen gas during the charging of batteries
• A neutralization material, such as soda ash, immediately accessible in the charging area
Most electric vehicles are designed to function for one shift before needing to be recharged. Only trained personnel should change or charge these batteries. Training should include proper battery-changing/charging procedures, the appropriate emergency procedures in the event of an acid spill or splash, and instructions on using the eyewash and shower facilities.
There are four potential hazards associated with battery charging and changing:
• Batteries are very heavy.
• Batteries contain sulfuric acid, which is highly corrosive and is a splash risk.
• Batteries can give off extremely explosive hydrogen fumes near the end of the charging process.
• Contact with battery cells can cause electrical short circuits that can result in burns to unprotected skin.
In addition to having a designated charging area, your facility or the designated charging area on the job site should have a site-specific safety procedure. A good way to help reduce your employees’ risk when working with batteries and rechargers is to always follow the recharger manufacturer’s recommendations. They will be specific to the type and model of recharger that will be used. Some other common-sense, OSHA-recommended practices include the following:
• Always use a lifting beam or equivalent material-handling equipment when lifting the battery out of a vehicle or replacing it. Using a chain and hooks can cause distortion and internal damage to the battery.
• When charging batteries, never pour water into acid. Only pour acid into water.
• Prohibit smoking in the charging area.
• Precautions should be taken to prevent open flames, sparks or electrical arcs in the charging area.
• Personal protective equipment, such as face shields, safety goggles, and neoprene or rubber gloves and aprons, is to be worn.
• All metallic jewelry should be removed before recharging. Other metallic objects and tools are to be kept away from the top of uncovered batteries.
• Be certain to unplug and turn off the charger before connecting or disconnecting the clamp connections.
Under normal working conditions, powered industrial truck forklift batteries can remain in service for 2,000 work shifts or charge/discharge cycles. Proper battery maintenance can prolong the life of the battery (it’s important never to over- or undercharge a battery) and help protect your employees. Battery failure could lead to mechanical breakdowns or accidents involving the employee operating the vehicle and/or other personnel. The manufacturer’s recommended service hours for a battery should never be exceeded, even if it continues to deliver power. When a battery is no longer functional, it should be recycled or properly disposed of. Spent batteries are a hazardous waste unless properly reclaimed at a lead smelter or battery recycler.
Electric vehicles are useful on the job site or at the workplace as long as people respect the hazards that accompany recharging the batteries.
KELLY is a safety and health specialist with Intec, a safety consulting, training and publishing firm that offers on-site assistance and produces manuals, training videos and software for contractors. She can be reached at 800.745.4818 and firstname.lastname@example.org. Joe O’Connor edited this article.