Compliance Strategies

A 15-Step Compliance Game Plan for Machine Guarding

Date First Published on SafetySmart Compliance: July 15th, 2013
Topics: Machine Guarding |

machine guarding 15 stepsMachines kill and maim. That’s why OSHA sets out strict machine guarding requirements in the Machinery and Machine Guarding Standard (29 CFR 1910, Subpart O). Here’s a 15-step game plan to help you comply.

How the Machine Guarding Standard is Organized

Subpart O includes 2 basic kinds of machine guarding requirements:

  • General machine guarding requirements that apply to all machines (1910.212); and
  • Specific requirements for particular kinds of machines, including:
  • Woodworking Machinery (Sec. 1910.213);
  • Abrasive Wheel Machinery (1910.215);
  • Mills & Calendars in the Rubber & Plastics Industry (Sec.1910.216);
  • Mechanical Power Presses (Sec. 1910.217); and
  • Forging Machines (1910.218).

15 Steps to Take

Step 1: Establish Machine Hazard Assessment Routine

As with other hazards, the first step in machine hazard control is machine hazard assessment. In the context of machine guarding, hazard assessment enables you to identify the hazards posed by particular machines and the guards necessary to control them. Hazard assessment should be performed on each machine in your workplace not only when it’s first installed but also:

  • When the machine is moved from one place to another;
  • At intervals recommended by the manufacturer or if there are no such recommendations, at least monthly;
  • Following an incident in which an injury or property damage occurs;
  • Following a near miss that had the potential to cause injury or property damage;
  • When the machine malfunctions; and
  • Before the machine is placed back into service after preventive maintenance or repair.

Step 2: Look for Machine Hazards in All 3 Areas of Dange

Focus on hazards in the 3 principle zones of danger that may require use of machine guards under the OSHA standard:

  1. The point of operation, i.e., the part of the machine where the cutting, shaping, boring, forming or other operation is done on the material;
  2. Moving parts in the apparatus that transmits power to the part of the machine doing the work, including flywheels, pulleys, belts, couplings, chains, cranks, connecting rods and gears; and
  3. Other moving parts of the machine, such as feed mechanisms and auxiliary parts.

Step 3: Look for Hazardous Machine Motions and Actions
What makes machinery so dangerous to workers are the mechanical motions and actions like the movement of rotating parts that can create in-running nip points. It’s crucial to factor the different types of mechanical motions and actions into your hazard assessment, including:

  • Motions like rotating, reciprocating, and transversing parts; and
  • Actions like cutting, punching, shearing, bending and stabbing.

Step 4: Evaluate the Machine Hazards You Identify

The next phase of the assessment is to evaluate identified hazards and what should be done to control them. Consider the type of machinery, the manufacturer, where and when it was purchased, the location of the machinery, preventive maintenance requirements. Also look at how many workers operate the machinery and the current training program for new workers, as well as any machine guards you currently use. Questions to ask when doing your assessment:

  • What are the hazards associated with the machine?
  • What are the guards and how do they work?
  • How do you use the guards?
  • How and under what circumstances and by whom may guards be removed?
  • What should you do if a safeguard is missing, damaged or ineffective?

Step 5: Consider Different Kinds of Machine Guarding Method(s)

At this point, the strategy shifts from hazard assessment to hazard control and the implementation of machine guards. The OSHA standard requires employers to use one or more of 5 machine guarding methods to protect the operator and other workers:

  1. Guards, or physical barriers that block workers’ access to the danger area. There are 4 basic kinds of guards:
    • Fixed guards that are a permanent part of the machine;
    • Adjustable guards that allow for flexibility in accommodating different sizes of stock;
    • Interlocked guards that automatically shut off or stop the machine when tripping mechanism is activated until the guard is put back in place; and
    • Self-adjusting guards in which the size of the opening in the barrier adjusts to accommodate the stock, e.g., enlarges to allow larger stock to enter.
  1. Devices that automatically stop the machine. There are 3 basic types:
    • Presence sensing devices that stop the machine’s operating cycle when a light field is broken, e.g., a worker sticks his hand in the danger zone;
    • Pullback devices that use a series of cables attached to the operator’s hands, wrists, and/or arms; and
    • Safety controls like tripwire cable, and two-hand control.
  1. Location/distance, i.e., placing machines away from work areas in locations that are hard to access;
  1. Feeding and ejection methods like automatic and/or semi-automatic feed and ejection, and robotic methods; and
  2. Miscellaneous aids like awareness barriers, protective shields and hand-feeding tools.

Step 6: Make Sure Guards Meet OSHA Requirements

In selecting guarding methods, keep in mind that guards must meet the following basic principles under the OSHA Standard:

  • They must prevent the worker’s body or clothing from coming in contact with hazardous moving parts;
  • They must be firmly secured to the machine and not easily removed;
  • They must ensure that no objects can fall into moving parts;
  • They may not create any new hazards such as shear points, jagged edges or unfinished surfaces;
  • They may not create any interference and prevent worker from performing the job quickly and comfortably; and
  • They must allow for safe lubrication of the machine without removing the safeguards, if possible.

Step 7: Make Sure Point of Operation Guards Meet OSHA Requirements

Point of operation guards must meet the appropriate OSHA standard for the kind of machine and hazard involved. Guards may be supplemented with—though not replaced by—special handtools that allow operators to place and remove materials from the machine without sticking their hands in the danger zone.

Revolving drums, barrels and containers must be guarded by an enclosure that’s interlocked with the drive mechanism, so that the barrel, drum or container can’t revolve unless the guard enclosure is in place.

Step 8: Make Sure Prime Mover Power Source Is Properly Guarded

OSHA requires proper guarding of prime movers, i.e., steam, gas, oil and air engines, motors, steam and hydraulic turbines and other equipment used as a source of power for the machine.

Step 9: Make Sure Shafting Is Properly Guarded

Each continuous line of shafting must be secured in position against excessive endwise movement. Additional rules apply to horizontal shafting 7 feet or less from the floor. Shafting under bench machines must be enclosed by a stationary casing, or a trough at sides and top or sides and bottom, as location requires.

Step 10: Make Sure Pulleys Are Properly Guarded

Pulleys with any part 7 feet or less from the floor or working platform must be properly guarded. Pulleys serving as balance wheels (e.g., punch presses) on which the point of contact between belt and pulley is more than 6 ft. 6 in. from the floor or platform may be guarded with a disk covering the spokes.

Step 11: Make Sure Belts, Ropes and Chain Drives Are Properly Guarded

Where both runs of horizontal belts are 7 feet or less from the floor level, the guard must extend to at least 15 inches above the belt or to a standard height. Exceptions: Where both runs of a horizontal belt are 42 inches or less from the floor, the belt must be fully enclosed; and in powerplants or power-development rooms, a guardrail may be used in lieu of the guard.

Step 12: Make Sure Gears, Sprockets and Chains Are Properly Guarded

Gears must be guarded by a complete enclosure, a standard guard at least 7 feet high extending 6 inches above the mesh point of the gears or a band guard covering the face of gear with flanges extended inward beyond the root of the teeth on the exposed side or sides.

Sprocket wheels (other than manually-operated sprockets) and chains must be enclosed unless they’re more than 7 feet above the floor or platform. Where the drive extends over other machine or working areas, protection against falling must be provided..

Step 13: Make Sure Machine Guards Are Properly Constructed

All things being equal, machine guards should be made of metal and created by the company that manufactures the machine they’re intended to guard.

Step 14: Make Sure Machine Guards Are Properly Secured

First choice: Affix the guard to the machine. If that’s impossible, the guard must be physically secured to the floor or another location near the machine.

Step 15: Make Sure Machine Guards Are Properly Maintained

You must inspect machine guards regularly and immediately after incidents or operational changes that may harm their effectiveness. Defective guards must be removed from service and replaced so that the machine doesn’t remain unguarded.