A new OSHA machine guarding standard took effect January 1st. Rite-Hite offers several options for shops to maintain compliance with the new rules and avoid any violations.
Assessing risk can be tricky and time-consuming. But any time new machinery is introduced to the facility, it should be done properly to achieve safety. Thanks to the passage of the Robotics Industry Association (RIA) R15.06 standard, risk assessments are now necessary.
OSHA cites its machine guarding standard as one of its top 10 violations in any given year.
Many professionals responsible for shop safety have been conducting risk assessments for increased safety as a matter of practice in anticipation of the new standard that took effect January 1, 2015. For those who are just beginning to unfurl the world of risk assessment, let's review some of the basics before looking into the final points of RIA R15.06.
Machine Guarding Risk Assessment Basics
Understanding and assessing these risks -- and ensuring compliance -- isn't easy. It's probably why OSHA cites its machine guarding standard, which includes robotic welding (29 CFR 1910.212), as one of its top 10 violations in any given year.
The Defender is an ideal device for safeguarding machinery in many manufacturing environments -- anywhere that a machine operator interfaces with a machine, robot or process.
First, facility/safety professionals need to identify and understand all codes and regulations that are applicable to their facility and operation. Next, they should examine the prevailing machine guarding choices for those applications in order to validate their safety system and its components. Although many guarding methods and products are available, not all can be applied universally.
Every machine guarding application has its own set of unique challenges and associated risk. The choices a facility manager makes for one application might not be the same -- or appropriate -- for the next.
Adding Safety-Rated Motion
RIA R15.06 references ISO 10218-1 & 2, which addresses robots, robot systems and integration. It requires added hazard identification accounting for robot motion and the task being performed. Additionally, it requires validation and verification of the safety systems employed, and of the designs that incorporate protective measures for the robot cell and the operator. Because every robot system is different, requiring risk assessments is an important step in protecting employees.
Technological advances in safety controls have reduced the physical footprint of robot cells, significantly shrinking the necessary floor space.
Some of the biggest changes this industrial robot standard will bring have to do with safety-rated motion and allowing for advanced programmable safety devices to be utilized. Software will now be allowed "safety-rated" control of various aspects of the robot's function, limiting the area in which the robot operates and the speed of robot motion. This is a departure from older standards in that programmable safety controls were not allowed.
Thanks to technological advances in safety controls, these long over-due applications can now safely be implemented. In the past, engineers designing these systems guarded for the maximum space, speed, and load of the robot. With these changes, the physical footprint of new robot cells should shrink. Coupled with the proper point-of-interaction safety devices, significant floor space savings can be realized.
Point-of-Operation Machine Guarding
When performing a proper risk assessment, point-of-operation guarding is probably the most involved aspect. While it's easy to place perimeter guarding around the entire process, most situations require a machine operator to interact with the process by loading or unloading materials (such as metals to be welded) and "running" the machine.
The Roll-Top Barrier Door by Rite-Hite Machine Guarding Products is designed to roll up and back to allow overhead crane loading and forklift access into work cells to load and unload larger parts.
Many details must be considered when it comes to this area, including the layout or design of the process, the limits of the system and properly identifying all associated hazards devising methods for hazard elimination and risk reduction.
The severity of the potential hazard must be determined, as well as the frequency or duration of exposure and the possibility of eliminating or limiting exposure. Using the distance formula as identified in OSHA guidelines can then help in choosing the proper machine guarding device. Per this formula, the safeguarding device has a prescribed location based on a number of factors, including secondary hazards that might harm a machine operator.
Presence-Sensing Devices Offer Some Protection
Light curtains, laser scanners and other presence-sensing devices are a commonly used and widely accepted method of machine guarding in manufacturing facilities from Tier 1 automotive to small machine shops and fabrication facilities. The automated process ceases once the safety device's infrared beam is tripped.
The Verti-Guard is a guarding solution for single or double robotic cells, part assembly, and conveyor openings.
In many instances these devices provide acceptable safety. However, they're not always the best choice in all applications, especially after a risk assessment is performed.
Benefits of a Physical Barrier
A fast-acting automated barrier door or roll-up curtain can go even further by eliminating exposure to both the dangerous movement of the machine and secondary hazards produced by the process, potentially eliminating risk and the severity of exposure.
Coupled with safety interlocks (up to PLe per EN ISO 13849-1 when integrated properly), automated barrier doors and roll-up curtains offer an increased level of protection for point-of-operation guarding. Because they provide safeguarding that can be seen, the opportunity for accidental work stoppage is greatly reduced. The physical separation they provide is a clear visual indicator that the machine operator needs to be on task.
The FlashFold is a unique vertical rising automated barrier door designed for safeguarding of machinery in applications where overhead crane or fork lift loading/unloading of the work cell is necessary.
These devices restrict access to the process and even contain secondary hazards such as smoke, flash, splash, mist or flying debris associated with automated welding operations by placing a barrier between machine operators and machine movement. These types of guards are an ideal alternative to light curtains and other presence-sensing devices in many situations.
Saving Space While Adding Safety
Due to the nature of a properly interlocked automated barrier door, certain aspects of OSHA's safety distance formula become moot because there is NO depth penetration factor -- thus allowing the safeguard to be placed much closer to the hazardous area. That means less space dedicated to a "safety zone," consequently reducing the manufacturing cell's footprint. This space savings is a huge benefit in most facilities. The smaller safety zone can make for a better ergonomic situation for the machine operator by limiting required motion and help increase productivity, an essential in today's competitive market.
Don't Fall Out of Compliance
Regardless of the safety device that ends up being selected for machine guarding, facility managers need to remember to perform a proper risk assessment. Although they can be tricky, this process will ultimately make a facility safer for workers and keep the facility in compliance with RIA R15.06.
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