The eternal battle is production versus safety, and at the very center of this is lockout, or better – avoiding lockout. The complaint, by both production and maintenance is that locking out equipment takes too long, or if they lockout, getting the machine back on line could be difficult. They will also argue that the machines have interlock controls that provide effective levels of protection and allow workers to efficiently (and safely) complete their work. The truth: maybe, maybe not.
Interlock systems (machine sensors)
An interlock is a device that will prevent one element from changing (moving), due to a state in another element. Interlocks in the work setting include electromagnetic switches, RFID proximity switches, light curtains, trap key interlock’s, etc. Interlocks open control circuits but do not isolate equipment from hazardous energy.
A good example to understand interlock is to examine your home washing machine. Washing machines have limit switches (newer models have both limit switches and lid locks) that would not allow the washing machine to run if the lid was in the open position. Raise your hand if as a child growing up you used a pen or a pencil (maybe your finger) to push that limit switch and watch the washing machine go around (author hand in the air). The limit switch (interlock safety device) keeps the machine from moving, but does it isolate it from the energy source? The limit switch does not unplug the electrical cord and turn the cold and hot water valves to the off position. And under the right circumstances (accidentally pushing down on the limit switch with your hand), the interlock can fail in its purpose and activate the machine
Interlocks have been used for decades and are one of the most misunderstood and improperly used safety devices installed on equipment. Their intended use, reliability and integrity from a safety perspective has evolved, where now there are Category 1, 2, 3 and 4 systems. These safety devices were to prevent accidents. They do not provide the equivalent level of protection that lockout provides, which is the OSHA standard. In our example of the washing machine, in terms of current OSHA language, as a child I was bypassing a guard and defeating a safety device. Technically, these are now considered Category 1 Interlock Controls. Similar devices are used every day under the guise of providing effective protection against the expected (or unexpected) start up or release of hazardous energy. Sadly, workers are injured and killed every year due to the failure or misuse of these perceived safety devices.
Interlock systems applied
Your company has Machine “X”, which is currently guarded by Plexiglas around all working parts, with interlocked access doors for workers to access. Operators are charged daily with clearing jams during their shift, which requires the worker to open an interlocked access door. This will stop the machine from running and allow the worker to clear the jam. When completed, the worker closes the door and the machine returns to normal operation.
This scenario plays out every day in companies across the United States and yet, this is in violation of the OSHA standard if the accidental energization of the machine would create a hazard for the worker. Machine “X” is still energized, and we are asking the worker to bypass a guard (they reach through the plane of the Plexiglas), place part of their body in the danger zone or at the point of operation. In this case, lockout should be applied because of the nature of the task and the measures of control in place. These types of interlocks are installed to protect workers in case they were suddenly exposed (door is opened) to an area where body parts should be placed. Over time, these interlocks have been integrated (wrongly) into the daily routines and tasks of production and maintenance where sentiment is that this is “safe” and “compliant.” Neither is true.
These types of task are often repeated several times per shift, to several times per hour. If the worker was to lockout the machine each time, they would spend a large amount of their work day locking the machine out and then returning to service. OSHA leaves it to the employer to determine (and document) what is acceptable in terms of protection when it comes to Alternative Measures of Control. The ANSI Z244.1 standard has recently provided in its 2017 update some guidance on how to determine if the Interlock Control Devices provide equivalent level of protection.
Much has advanced in the technology, reliability and integrity of Interlock systems over the past two decades. The industry has seen the development and deployment of Category 3 and Category 4 Interlock Control Devices. These systems have been proven to increase productivity (uptime) and decrease lockout (downtime), but they do come with a requirement of significant investment in time and resource to install, implement and maintain, and still do not meet OSHA requirements. From the scenario on Machine X, it would be a wise investment to install an interlock system to save a few minutes, several times an hour — which then does increase your production uptime AND protect your workers from hazardous energy.
Too often we find ourselves in conversations with customers who are looking for solutions to avoid lockout as a means to increase production uptime. The majority of the industry has equipment that requires three or fewer locks/devices to achieve a zero-energy state. There is a good argument to use Interlock Control Devices in a particular industry, with particular equipment and involving particular tasks. Invest and protect wisely for true gains in uptime and worker safety.
A transport company has been ordered to pay more than $63,000 in fines and court fee’s after a worker’s hand was crushed between two containers that were being moved with a forklift in Western Australia.
Mineral Trans WA and another entity operated Cranes Haulage in August 2014 when a truck driver transported sea containers to a yard in Esperance, Western Australia to be unloaded with a forklift by the general manager.
The truck driver was releasing twist locks that attached two containers when they became stuck, and as they were separated his left hand was crushed. He was transported to a local area hospital. He required skin grafts and pins to repair open fractures.
Mineral Trans pleaded guilty in Esperance Magistrates Court to failing to provide and maintain a safe workplace, and by that failure, caused serious harm to an employee.The company also admitted allowing an employee to operate a forklift without the appropriate licence.
Mineral Trans was fined a total of $58,000 and was also ordered to pay $5542 in costs.
WorkSafe WA Commissioner Ian Munns said, “the hazard should have been foreseen. The worker should have been prohibited from removing the twist locks from the bottom container until the top container was safely removed from the pedestrian area.”
Following the incident, Cranes Haulage stopped separating sea containers and the general manager has obtained an appropriate licence to operate a forklift.
Two contractors working near a 6.9kV electrical bus were injured in an arc flash incident on March 16th at the Tennessee Valley Authority’s Sequoyah Nuclear Plant near Soddy-Daisy, TN, northeast of Chattanooga.
According to an event notification report from the U.S. Nuclear Regulatory Commission (NRC) posted Monday, the two contractors were transported to a medical facility for treatment. “The cause of the arc flash is not understood at this time, an accident investigation has been initiated by TVA,” the report said.
The two injured contractors sustained first and second-degree burns. Both are employees of Day & Zimmerman, an engineering, construction and security firm based in Philadelphia. TVA told television station WRCB that it has suspended similar work activities until the cause is understood.
Neither of the workers were shocked or contaminated by radiation in the incident. The TVA’s two nuclear reactors at the site, Sequoyah Unit 1 and Unit 2, remain at 100 percent power, the NRC said.
When an arc flash happens, it does so without warning and is lightning quick. The result of this violent event is usually destruction of the equipment involved, fire, and severe injury or death to any nearby people. Proper safety and protection measures must be taken to limit the damage from an arc flash which include conducting an arc flash study, short circuit study, and NFPA 70E electrical safety training.
Promontory, UT – A propellant explosion trapped an Autoliv North America worker inside a burning building. He was rescued, but died of his injuries.
64-year-old Ronald Larson was trapped in a fire that consumed the mixing portion of Autoliv North America’s Promontory (UT) facility. He died at the hospital following an explosion in a laboratory where he was making propellants for air bag inflators earlier this week.
OSHA is leading the investigation into the industrial accident that cost 64-year-old Ronald Larson his life. The immediate cause of the explosion has yet to be fully been determined.
According to local media, Larson “was trapped inside and on site personnel were making efforts to try and extricate him from [Autoliv’s mixing] building.” The employee was successfully extricated from the building and taken to a local hospital with severe burns. Unfortunately, Larson had stopped breathing upon arrival at the hospital. Lifesaving efforts were in progress, but he was pronounced deceased a short time afterward.
Larson is reported to have been alone in the mixing portion of the building at the time of the explosion and subsequent fire. Two other workers were injured in the fire and in trying to rescue their co-worker. Their injuries are not life-threatening.
Autoliv is based in Sweden and has several facilities in Utah under the Autoliv North America brand. They are the world’s largest automotive safety supplier.
This Autoliv North America location in Promontory was the site of two previous industrial explosions and fires. In 2015 an explosion injured an employee there, and in 2013 a flash fire burned a worker’s arms and face. These prior incident will factor into OSHA’s investigation of the company’s safety practices and could lead to steeper fines if lapses in environmental health and safety are found to have been willful.
PETERS TOWNSHIP, PA – Cameron Allen Funk, 19, Greencastle, was found dead at Mellott Manufacturing, according to a release from Pennsylvania State Police, Chambersburg. Funk’s death was caused by a heavy piece of machinery falling on him.
Dispatchers identified the incident as an industrial accident with entrapment when first calling emergency personnel to the scene. An update soon after indicated there was no entrapment, but that a person was dead. State police arrived on scene around 3:00 PM on Wednesday, February 28.
State Police, the Franklin County Coroner’s Office and OSHA are investigating the incident. As of right now the death ruled an accident.
“The employer has no prior OSHA inspection history,” said Joanna P. Hawkins, deputy regional director for the U.S. Department of Labor, Philadelphia. “OSHA has up to six months to complete its investigation.”
Mellott Manufacturing makes conveyors and machines for the sawmill, pallet and woodworking industry. Sixty employees work there, per the company’s website.
This is the fourth death in Franklin County, PA in the last month from heavy machinery. Three people died earlier this month as a result of a crane accident at Manitowoc Crane in Shady Grove, just east of Greencastle.
Baiting Hollow, NY – A worker is in critical condition after he became stuck inside a conveyor belt housing. Once in the confined space, the man lost consciousness and went into cardiac arrest at the sand and gravel pit where he was working.
According to local police reports, the 40-year-old man “became lodged inside the conveyor belt housing of a plant screener that is used for sifting soil on the property.”
The worker, currently in critical condition, is an employee of BGLJ Servicing Corporation. He was working at a property used for excavating material.
The employee shut the conveyor off and crawled into a small opening to free a jam. While in the space, he got stuck and lost consciousness. His co-worker pulled him out and emergency responders were called to the scene.
Alhambra, CA – A foundry worker lost both legs last August after a coworker re-energized the machine he was working in. Alhambra Foundry has been fined $283,390 for federal workplace safety and health violations including lack of permit-required confined space program, inadequate machine-specific lockout procedures, missing accident prevention signage, and not having a confined space attendant monitoring his entry.
According to federal safety regulators, two Alhambra Foundry employees were cleaning and unblocking a 38-feet-long auger screw conveyor at the bottom hopper of an industrial air filtration device without effectively locking out the equipment. After the cleaning was done, one of the workers re-entered the 20-inch square opening to retrieve a work light from inside the confined space. Unfortunately, at that same time a maintenance worker 45 feet away energized the equipment to perform a test. The moving auger screw pulled the worker into the screw conveyor and both of his legs had to be amputated in order to get him free of the machine.
The Cal/OSHA Chief stated that “sending a worker into a confined space is dangerous, especially inside machinery that can be powered on at any time…Employers must ensure that machinery and equipment are de-energized and locked out before workers enter the space to perform operations involving cleaning and servicing.”
In their investigation, Cal/OSHA found that the screw conveyor was not de-energized and locked out before workers entered the hopper, and accident prevention signs were not placed on the controls. Alhambra Foundry lacked specific procedures for de-energizing and locking out the equipment and additionally, the worker re-entering the hopper was not monitored by a confined space attendant.
Unfortunately, Alhambra Foundry was cited for similar violations eight years ago and therefore were issued a willful serious accident-related violation for failing to take appropriate measures to protect workers performing cleaning and servicing operations.
Helena, AL – OSHA has proposed fines of $195,144 against ABC Polymer Industries LLC after an employee suffered fatal injuries when she was pulled into a plastics recycling machine at the Alabama facility in 2017. OSHA has determined that ABC Polymer’s machine guarding failure was “willful” and resulted in what they’ve called a “preventable tragedy.”
Following their investigation, OSHA levied one willful citation against ABC Polymers for failing to provide machine guards which protect employees from hazards like getting caught in machinery and amputation dangers. Of the 16 violations found at the AL facility, the willful machine guarding failure amounts to the largest portion of the proposed fine total. OSHA’s Birmingham Area Office issued a statement: “This company’s failure to install machine guarding equipment has resulted in a preventable tragedy.”
ABC Polymer Industries was also cited for repeat, serious, and other-than-serious violations, including failing to evaluate all powered industrial trucks every three years, not having machine specific lockout tagout procedures, and failing to install a rail system on both sides of an open platform.
According to the local Coroner’s office, the employee, Eva Saenz (age 45), was working next to rollers and bent over to cut a piece of plastic when she got pulled up into the rollers and equipment. She was pronounced dead at the scene by emergency responders.
ABC Polymer Industries makes polypropylene bulk storage bags and flexible containers for industrial markets. They are one of the largest suppliers of flexible intermediate bulk containers in North America as well as a manufacturer of polypropylene concrete fibers, and extruded PP products, including microsynthetic and macrosynthetic concrete fibers.
Chattanooga, TN – Two workers performing maintenance on a sewer line in Chattanooga were injured in a confined space explosion this week. The two men were employees of SpectraShield, a subcontractor used by the City of Chattanooga.
The men were down in a manhole when the flash fire broke out, they were able to escape the confined space and call for help. Firefighters were dispatched, the fire was already out when they arrived. Tennessee’s OSHA division is involved in the investigation into the cause of the accident.
One worker suffered minor burns but was not hospitalized. The other was transported to a local hospital to be treated for second-degree burns.
Canton, OH – A Fresh Mark employee died recently after his leg was caught in a waste grinder. Ohio’s Stark County Coroner’s Office stated that 62-year-old Samuel Martinez stepped into a chute and was caught in a waste grinder at the meat processing plant outside of Cleveland. Authorities say he died at the scene.
Fresh Mark Inc. supplies grocery stores, restaurants, and food service companies with bacon, ham, hot dogs and deli meats.
Fresh Mark officials are working with authorities to determine the cause of the accident.
Machine safety is crucial to workplace safety. Machine Safety and Lockout Tagout procedures, training, and awareness save lives, maintain production schedules, and keep machinery operational on a daily basis and are the foundation of a safe and efficient workplace.