Machine Risk Assessment vs. Safeguarding Assessment? Start 2020 off on the right safety foot.

When it comes to accidents, manufacturing ranks second highest of all industries. That comes despite OSHA regulations and American National Standards Institute (ANSI) standards. A key culprit is unguarded hazardous machinery.

Year after year, OSHA issues thousands of citations and levies millions of dollars in fines for machine safeguarding violations in an attempt to prevent injuries and save lives OSHA 1910.212(a)(1) is the most common section citation, whereby “one or more methods of machine guarding shall be provided to protect the operator and other employees in the machine area from hazards” followed by OSHA 1910.212(a)(3)(ii) whereby “the point of operation of machines whose operation exposes an employee to injury shall be guarded.

Why the disregard?

Why is this so? Often facility safety managers are lulled into a false sense of security because a serious accident has not yet occurred or because accidents are rare in their facility. Other managers might wrongly suppose that their newly purchased machinery arrives fully compliant, not realizing that OEMs are typically concerned with new machinery price competitiveness, not necessarily guarding compliance. Still other managers may wrongly assume that older machines are “grandfathered in” before OSHA was formed.

For whatever reason, approximately HALF of industrial machinery has not been properly safeguarded.

That is the bad news.

The good news is there is a way to determine compliance through an assessment of the machinery on the plant floor, as outlined by ANSI B11.0. There are two types of assessments that reign supreme: the Risk Assessment and the Safeguarding Assessment. This article will address both methods and how they help an organization better protect the people operating the machines and reduce the risk at the facility.

Risk assessments should be conducted annually, including whenever a new machine is installed or a major change to an existing machine or production line has taken place. Additionally, in an ideal world, a pre- and post-assessment would be done to verify that the hazards identified in the assessment were properly mitigated.

Risk assessment

What a risk assessment is comprised of is outlined in ANSI B11 Series Standards for Industrial Machinery, ANSI/RIA R15.06-2012 Safety Standards for Industrial Robots, and the National Fire Protection Association (NFPA) 79-2015 Electrical Standard for Industrial Machinery.

The overarching goal of a task-based risk assessment is to identify hazards associated with machinery or robots. This requires an on-site visit by a risk assessment professional who audits and assigns each machine a risk rating based on three considerations: Severity of Injury, Exposure Frequency, and Avoidance Likelihood, which produces a Risk Level. Today’s risk assessment specialists use software-based tools that can make the process quicker than working through a pen-and-paper risk assessment form.

In advance of the facility visit and based upon project scope, the risk assessment specialist will need to review a comprehensive machine list and potentially other documentation such as: corporate safety standards, lockout/tagout (LOTO) procedures, electrical and mechanical drawings, floor-plan layout and equipment manuals.

The scope of assessing a piece of machinery for risk begins with reviewing its operational states with functionality tests performed to help identify potential hazards during machine start-up, cycle, and stopping. The risk assessment specialist may perform a Stop-Time Measurement (STM) test to determine the machine’s reaction time after receiving a stop signal to ensure proper safety distance of safeguarding devices. The specialist will also establish if a passerby or other employees in the area could be hurt if an incident occurs, in addition to the operator.

Along with assessing the production risks of the machine, the risk assessment specialist must analyze the tasks performed by the machine operator as they relate to interacting with the machine, loading and unloading materials, planned and unplanned maintenance methods, frequency of tool changes, and general housekeeping.

During the risk assessment, the specialist will photograph machines and generate a final hazard report documenting their assessment findings and risk levels. The hazardous findings of each machine are broken down into the following ranked classifications:

Critical: There is an imminent life-threatening or dismemberment hazard and immediate action is needed to reduce risk and improve operator safety
Mandatory: There is an imminent hazard that creates potential for injury and action is required to reduce risk, improve operator safety and to comply with OSHA/ANSI standards
Compliant: There is not a recognized hazard that creates potential for injury and no action is required.

Safeguarding assessment

While a risk assessment helps to identify a problem, it does not provide specific safety solutions nor cost estimates. For that, a safeguarding assessment is needed.

During the safeguarding assessment, a specialist will visit the site and conduct an intensive audit of each machine and identify compliance in five guarding areas: safeguards, controls, disconnects, starters and covers. The safeguarding specialist may request copies of electrical, pneumatic or hydraulic schematics, operator manuals and ask for control panel access so that engineers can review the control circuit for electrical compatibility of any proposed safeguarding solutions and to verify reliability of the control circuit to determine the interfacing requirements of suggested equipment. Then the safeguarding specialist will focus on risk reduction using this basic methodology:

– Eliminate Access — A good safeguarding system eliminates the possibility of the operator or other workers placing parts of their bodies near hazardous moving parts.
Reduction in Exposure — A machine safeguard should not be able to be removed, bypassed or tampered with by the operator. To minimize risk exposure, all guards and devices must be securely mounted at the point-of-operation and durable enough to withstand industrial environments, vandalism and heavy usage.
– Create No New Hazards — A safeguard defeats its own purpose if it creates a hazard of its own such as a shear point, a jagged edge, or an unfinished surface which can cause a laceration. The edges of guards, for instance, should be rolled or bolted in such a way that they eliminate sharp edges.
– Create No Interference — Any safeguard which impedes a worker from performing a job quickly and comfortably might soon be overridden or disregarded. Proper safeguarding can actually enhance efficiency since it can relieve the worker’s apprehensions about injury.
– Allow Safe Lubrication — Locating oil reservoirs outside the guard, with a line leading to the lubrication point, will reduce the need for the worker to enter the hazardous area.
Administrative Controls — Without administrative oversight and supervisory control, a machine safeguarding program will fail. Training is key to establishing a safety culture. Operators need to trained to follow the Standard Operating Procedures provided by the machine manufacturer in order to reduce hazards and related risks.

Uncovering gaps in protection

Unlike a risk assessment, a safeguarding assessment recognizes both the problem and the solution. A final compliance report and safeguarding project proposal is issued to facility management which identifies deficiencies or gaps where each machine is not in compliance with current or specified regulations and standards. When not in compliance, the proposal offers standard and customized safeguarding solutions, along with associated costs and timelines to help bring machines into compliance and reduce risk. Each proposed solution is carefully weighed against factors such as risk-reduction benefit, productivity, technological feasibility, economic impact, and maintainability.

In this way, a machine safeguarding assessment follows the OSHA/ANSI approach to controlling machine hazards: eliminate the hazard by design; or control the hazard by guarding, posted warnings, personal protective equipment, and employee training.

Risk reduction strategies

When evaluating risk reduction solutions to address identified hazards, consider each machine and its unique risks. Three basic methods are available.
– Eliminating or reducing risks to a “tolerable” level by installing a new, inherently safe machine. Please note that what constitutes “tolerable” to one company is not necessarily tolerable to another.
– Installing the necessary safeguarding equipment on an existing machine to minimize risks that cannot be eliminated. Fixed enclosing guards, protective devices such as light curtains, palm buttons or presence sensing mats, and training on the safe working methods of the machine are all necessary to reduce injury risks.
– Changing the production process to eliminate the hazard. Perhaps the operator performs actions that increase his exposure to serious hazards? Or recent changes upstream have created a more dangerous environment? Even a small change in procedures can make for a safer, more efficient operation.

Conclusion

Both risk assessments and/or the safeguarding assessments are critical first steps in any machine or robot safeguarding project as outlined in ANSI B11 Series Standards for Metalworking, OSHA 1910.212 General Requirements, ANSI/RIA R15.06-2012 Safety Standards for Industrial Robots and NFPA 79. These standards pave the way for risk-reduction measures that are both effective and economical. Machine risk assessments provide a comprehensive hazard analysis with a risk ranking; machine safeguarding assessments identify safeguarding solutions and provide cost estimates for implementation. Which one is right for an organization depends upon the specific needs of the organization, the organization’s objectives, desired outputs and risk levels.

Related Blogs:

Machine Risk Assessment Process

Machine Safeguarding Assessment

Machine Risk Assessment

Machine Risk Assessment – Inquiry Confirmation

Remote Safeguarding Assessment

Safeguarding Mechanical Power Presses

Mechanical power presses (a.k.a. punch presses, stamping presses, flywheel presses), have existed in the U.S. since 1857. They were originally designed as either full-revolution, or part- revolution, both of which still exist, although the latter currently represents an estimated 90 percent of the roughly 300,000 mechanical power presses being used in the United States today.

This blog will address part-revolution presses only. These are often referred to as “air clutch” presses, made by dozens of manufacturers. The idea of safety for these machines has existed since 1922, when the first ANSI B11.1 Safety Standard was developed. The latest version, ANSI B11.1-2009 is the 10th update of that standard. This is generally considered to contain the “Best Safety Practices” for press users.

In the early 1970’s, OSHA promulgated a “machine specific regulation” for mechanical power presses, their CFR SubPart O, 1910.217. Very few changes have been made to that regulation since then. Keep in mind that OSHA’s 1910.217 Regulation was taken from ANSI B11.1 using a version that was freshly updated for OSHA in 1971. ANSI has updated their B11.1 four times since that time. Every update adds new, more stringent requirements than the previous version.

Although many companies have long since met the basic OSHA requirements for their presses, a significant number of those shops have yet to make updates to meet the latest ANSI B11.1 Standard. When OSHA regulations came 46 years ago, press control systems were primarily relay-logic systems, designed to meet OSHA’s initial requirement for “Control Reliability” and “Brake Monitoring.”

Press control systems manufactured in the mid 1980’s and beyond have been mostly solid-state, designed to meet the ANSI Standard concept for the “Performance of Safety Related Functions.” One of the advantages to solid-state controls are the features built-into them. Two of these are a: built-in “Stopping Performance Monitor” and built-in “Stop Time Measurement,” which prevents users from having to use a portable device to determine “Safety Distance” when applying Light Curtain and Two-hand Control devices.

Mechanical Power Presses require some combination of guards and/or devices to reduce or eliminate exposure to hazards at the “point of operation” where the dies close. Safeguarding alternatives include: Point-of-Operation Guards, Awareness Barriers, Light Curtains, and Two-Hand Controls.

1) Point-of-Operation Guards
Point-Of-Operation Guards are typically used for continuous operations where coil-stock feeds into the press as it operates in an uninterrupted mode of operation.

By OSHA’s definition, a guard must prevent people from reaching over, under, through, or around it. (OUTA is an acronym easy to remember; This guard keeps you “OUTA” here.) Guards must meet one of two measurement scales (the OSHA guard opening scale or the ANSI/CSA guard opening scale), to ensure that a small hand can’t reach far enough through any opening to get hurt.

To discourage misuse, hinged or sliding guard sections are often electrically interlocked, so that they remain in position (closed) during press operations. Without interlocks, movable sections can easily be left open, whether intentional or not, leaving Operators and others in the area unprotected.

Guard Interlocks are attached to hinged or moving guard sections, since access to the point-of-operation is most often made through those openings. Interlock attachment is best accomplished with tamper-resistant fasteners to discourage cheating the switch.

Many older guards use simple lever-arm or push-button switches. Not only are these switches easy to cheat with tape or wire, they are also spring-operated, leaving them subject to failure it the spring breaks. Newer switches are free of springs, and use actuators with a unique geometry, making them much more difficult to defeat.

2) Awareness Barriers (for low-level hazards only)
Another common method of safeguarding on coil-fed presses is an “Awareness Barrier” (A/B). They should completely surround press auxiliary equipment with railings, chains, or cables, suspended on floor stations. Although they don’t provide the same level protection as a guard, they do help to limit access to hazards on auxiliary equipment like coil-payoffs, feeds, straighteners, etc.

Awareness Barriers are considered superior to just a yellow line on the floor, because to get beyond the A/B requires an intentional act and some physical contact with them. This means the person is well aware that they are entering a hazard area, contrary to their safety training. Auxiliary equipment may also require that ingoing rolls are covered to prevent entanglement with long hair or loose clothing.

Awareness barriers should also have several Danger or Warning signs attached to them specifying what the hazards are in going beyond the A/Bs. Examples of sign verbiage might include: moving coil stock, ingoing pinch points, sharp edges, tripping hazard, etc.

3) Light Curtains
Light Curtains have been around since the mid-1950’s. They consist of a vertically mounted transmitter and receiver with closely spaced beams of infra-red light, creating a flat sensing-field. When fingers, hands, or arms that reach through that sensing-field, the press cycle is prevented or stopped to avoid operator injury.

One of the reasons that presses make a good application for light curtains is that they can be stopped mid-cycle very quickly. Light curtains can be used for either single or continuous applications. The only thing that light curtains don’t provide is “impact protection” should something break in the point of operation and be ejected in the operator’s direction. Where that’s an issue, poly carbonate shields or guards may be appropriate.

Like any safeguarding device, light curtains should be “function-tested” before every operating shift to ensure that they are continuing to provide protection. Make/model specific “function-test procedures” are usually available on each light curtain manufacturer’s website.

4) Two-Hand Controls
Two-Hand Controls are considered a safer means of cycling a press than a foot-switch because both hands must be in a safe position to use them. When cycling a press with a foot switch, hands can be anywhere. When operating a press in the single-cycle mode of operation, it’s possible to use a two-hand control as a safeguarding device as well. This requires that they meet a list of rules in both OSHA and ANSI.

Ten of the basic requirements for a two-hand control being used as a safeguarding device (in the single-cycle mode of operation) include:
1) protection from unintended operation
2) located to require the use of both hands (no elbow & finger tips)
3) concurrently operated (actuation within half-second of each other)
4) holding-time during the downstroke (hazardous portion of cycle)
5) anti-repeat (push and release both actuators for each single cycle)
6) interrupted stroke protection (for all operating stations)
7) separate set of two-hand controls for each operator
8) mounted at a calculated “Safety Distance” from nearest hazard
9) control system to meet “Performance of Safety Related Functions”
10) Stopping Performance Monitor is also required

When running high-production operations, don’t forget to consider ergonomics when choosing and installing two-hand controls. Several manufacturers of low-force and no-force actuators are on the market.

Also required by OSHA on Mechanical Power Presses is an electrically interlocked “Safety Block” whenever dies are being adjusting or repaired while they are in the press. The interlock is required because safety blocks are very seldom designed to hold the full working-force of the press (please refer to our Die Safety Blocks blog for additional information).

Mechanical Power Presses require two types of OSHA inspections:
1) Periodic and regular (typically quarterly) inspections of the press parts, auxiliary equipment, and safeguards . . . (don’t forget to document)
2) Weekly inspections of; clutch/brake mechanism, anti-repeat feature . . . along with other items (don’t forget to document)

OSHA requires training (in 1910.217) for anyone who cares for, inspects, maintains, or operates mechanical power presses.

ANSI B11.1-2009, requires training for “all (people) associated with press production systems, including operators, die setters, maintenance personnel, supervisors, which must also include (OSHA) 1910.147 Lockout/Tagout.”

Please call 1-800-922-7533 or visit rockfordsystems.com for more information.