Page 26 - OHS, April 2022

FACILITY SAFETY
Improving In-Plant Safety with Fixed,Automated & Moveable Barriers
ThThe right combination of barriers throughout a facility can protect employees.
LBY WALT SWIETLIK
arge industrial facilities,
expansive warehouses, and massive distribution centers can be dangerous places for
employees. Material handling vehicles, machining equipment, and fall hazards in such facilities all present unique safety challenges.
Forklifts, automated guided vehicles (AGVs), pallet jacks, and other materials handling vehicles are necessary to move products in bulk or efficiently from storage to shipping. Yet, these in-plant vehicles can be dangerous for workers on foot inside a plant. Forklifts alone were involved in nearly 7,300 reported accidents in 2020. There were 78 reported deaths due to forklift-related incidents in 2020.1
According to OSHA, falls are among the most common causes of serious work-related injuries and deaths. In fact, slips, trips, and falls account for nearly 700 deaths each year.2 Fall protection continues to be one of OSHA’s Top 10 most frequently cited violations, but machine guarding is routinely part of this annual list, too.3 More than 1,100 violations were uncovered in 2021.
Many of these incidents could have been prevented with proper training and the right in-plant safety equipment. Specifying the proper barriers for the facility can help mitigate the daily risk employees encounter.
Reducing Floor Accidents
Unlike painted yellow lines, physical barriers can help prevent forklifts from striking pedestrian traffic. Physical barriers are much harder to ignore, and serve additional functions as well. Beyond separating employees from automated processes and dangerous workspaces, barriers may also be used to protect production equipment and/or the building itself from damage by forklifts, AGVs, or other vehicles.
Many manufacturers rate industrial barriers based on their ability to stop an impact of 10,000 pounds at 4 mph—which has been an industry standard for more than 30 years. While this rating provides
a meaningful reference for a specific load at a specific speed, it fails to define several key variables:
How is the barrier’s performance affected as the mass of the impacting vehicle increases?
■ How is the barrier’s performance affected as impacting vehicle’s speed increases?
■ How severely was the barrier damaged by the impact? Is replacement necessary?
■ How much did the barrier deflect during impact? Did it stop the load soon enough to prevent injury or damage?
To fully address these questions, a test methodology has been developed to quantify specific application variables and determine barrier ratings in terms of total kinetic energy absorption, instead of a specific mass and speed.
Called BLAST (short for ‘’barrier load and speed testing”), it is centered on the formula for kinetic energy (KE = 1⁄2mv2, where m=mass [weight] and v=velocity), which considers both the weight and speed of the impacting object to help determine the most appropriate barrier based on the application.
For example, a forklift weighing 17,500 pounds (including the load it is carrying) traveling at 3 mph is going to be able to hit a barrier with minimal damage to the barrier, while keeping employees or product on the other side safe.
However, that same forklift traveling at 4 mph means the barrier will stop the load, but could potentially sustain damage or inflict injury.
If the 17,500 pound forklift was traveling at 5 mph, the impact from the vehicle cannot be fully absorbed and thebarrierwouldnotbeabletostopthe load—indicating that this barrier should not be used for this application.
Limiting Exposure
Whether it’s an industrial facility that uses robotic welding arms or a distribution center that utilizes automated stretch- wrapping machines, there are several potentially dangerous work cells that
employees often work with or near. In these examples, having access to the work cell is necessary when a machine is powered down, but can be disastrous for the human worker when the machine is performing its task.
This is where automated barriers come into play. Unlike presence-sensing devices such as light curtains and laser scanners, perhaps the most significant benefit of an automated barrier door is it provides a physical barrier that can protect employees by restricting access to dangerous machine movement and containing the process. This is particularly important for processes such as robotic welding, where sparks and debris can become hazardous for nearby employees or machine operators. It’s also important in automated tasks like stretch wrapping, in which inertia keeps machinery in motion even after it’s been shut down.
The most advanced roll-up automated barrier doors offer high-speed, high-cycle technology, as well as PLe safety rated non- contact interlock switches and controls. Most automated doors function from the top down, but some have been designed to operate from the ground up. This allows machine operators to easily interact with the process utilizing overhead cranes to load and unload large, heavy pallets. They are also a great option for interaction points that have a very limited space.
Preventing Falls
More facilities are growing upward instead of outward to better utilize the existing footprint. However, this comes with risk as falls from heights are more dangerous to workers and product. To help supplement OSHA regulations, many companies look to organizations like ANSI for “best practice” guidelines.
ANSI standard: Specification for the Design, Manufacture, and Installation of Industrial Work Platforms (MH28.3: 2009), states: any gate providing access opening through the guards for the purpose of loading and unloading material onto a work platform shall be designed such that the elevated surface is
22 Occupational Health & Safety | APRIL 2022
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