Hazards machine actions

Sweep Devices A sweep device is a mechanism connected to the point-of-operation action of a machine. The device sweeps an operator s hands or body away from the point-of-operation if present when the machine action begins. Some standards do not allow use of sweep devices. In some applications sweep devices can create a shear hazard between the sweep and some other machine component that can cause injury to an operator. 

What additional hazards do power sources (such as gasoline, electricity, compressed air, or hydraulic fluid) add to tools and machines beside the hazard of the tool and machine actions ... 

Machines are used to cut, bore, transfer, haul, and load mined materials or materials used in mining. There are machines and tools for maintenance and repair. Each contains hazards of various kinds. This discussion will be Hmited to three major considerations with machines and tools energy and energy sources, machine actions and protecting people from them, and man-machine interfaces. 

Caustic materials contained in the admixtures can cause reactions on exposed skin, ranging from mild irritation to severe bums. Most of the ingredients are classed as primary irritants. With liquid admixtures, bums can occur immediately. Because of the serious hazard to exposed skin and eyes, personal equipment is required for all those in the vicinity of the shotcrete machine and nozzle. These include long-sleeved shirt or coveralls. In addition, prior to shooting, protective cream or lotion should be applied to skin areas likely to be exposed to the caustic chemicals. A suggested treatment is to wash exposed skin with water and rinse with vinegar followed by treatment with a protective cream. All exposures to the eye require the immediate attention of a physician immediate action would be to flush the eye with copious amounts of water [120, 121]. 

In addition to the machine guarding, the control system should be interlocked with an electronically monitored failsafe system. The control software should have an awareness of the position and action of all moving parts and measurement devices. Therefore, if an unplanned incident or out-of-protocol action does occur, the system will take action or stop action to minimize the likelihood of additional safety hazards. In some cases, as with system calibration or super user access, graded access levels can be custom-built into the design for specialized and infrequent operations. 

Recent developments in machine controls and changes in U.S. standards now permit the initiation of some machine cycles without an overt action on the part of the machine operator. These systems, known as presence-sensing device initiation (PSDI), automatically cycle the machine upon the sensing-device determination that the operator is clear of hazard areas. Similar systems have been utilized outside the United States, but normally the design and function of the machines have been approved by government or professional third parties. Many safety professionals recommend that PSDI be utilized only if the machine control has been designed and periodically tested by the original machine manufacturer. Under no conditions should any part of the body other than hands be placed inside dies or other points-of-operation while machine power is active. 

Inappropriate response and incompatibility. These two factors can also cause human errors. Three examples of inappropriate response by a person are he/she disregarded the specified procedures, he/ she defecfed a hazardous condihon buf took no corrective action, and he/she removed a safeguard from a machine to increase output. Incompatibility refers to fhe incompafibilify of a person s workstation with respect to factors such as reach, size, feel, and force. These incompatibilihes can cause accidenfs and injuries. 

Periodic, scheduled facility safety inspections are essential in any operational area, especially where hazardous tasks are performed on a regular basis. Compliance with safety inspection requirements should not be difficult to accomplish since similar requirements should already exist in an established occupational safety program. The facility inspection encompasses all facets of daily operation and considers the human-machine interface a primary candidate area for potential mishaps. Frequent facility inspections are an excellent method of maintaining current awareness of facility conditions and how those conditions affect, or might affect, the safe operation of that facility. A system should be in place to ensure implementation of corrective actions and to track repetitive items. Results of inspections should be properly documented and accountability for discrepant items appropriately determined and assigned in order for the inspection process to be effective. If properly performed, the facility safety inspection is an excellent tool in the overall success of the system safety function. 

Machine safeguards protect workers from preventable injuries. Safeguard any machine part, function, or process that may cause injury. A wide variety of mechanical motions and actions can create hazards to the worker. Hazards can include rotating members, reciprocating arms, moving belts,... 

Note that the definition identifies a hazard as an attribute of three items activity, condition, and circumstance. That means that a personal action can be a hazard. It means that a characteristic of a machine, operation, or process can be a hazard. The idea of a circumstance suggests that something surrounding or inherent in an adverse event can be a hazard. The event may be simple or complex. 

Another kind of hazard is getting caught in a machine or tool. Many people have experienced the pinching action of a pair of pliers. One can get caught in many ways. Power transmission elements, such as belts, chains, gears, linkages, shafts, and other components, have pinch points or catch... 

There are five types of machine motion (see Figure 13-2) that create machine hazards rotation, reciprocating or transverse motion, in-running nip points or pinch points, cutting actions, and punching, shearing, and bending. 

Run Controls Run controls turn on a machine and its action. If someone inadvertently turns on the run control or something presses or falls against it, hazardous conditions may result. Putting guards on or recessing run controls prevents accidental starting of a machine. Chapter 33 discusses various methods for guarding switches and run controls from inadvertent activation. 

Designers making decisions about machine or workplace design, plant layout, work procedures, etc. They need to predict the actions of the people who will use these products and the hazards which will arise in use. 

Three types of machine motion and four types of actions may present hazards to the worker. These can include the movement of rotating members, reciprocating arms, moving belts, meshing gears, cutting teeth, and any parts... 

Machine safety checklists can be used to identify potential and actual hazards in the workplace. Checklists provide a baseline for hazard identification and action planning that m be required to correct a hazard. 

The task analysis technique has been developed mainly to handle human factors (in HAZID and other methods). In HAZID this is helpful in addressing human factors such as human error, man—machine interface, and procedural error. Of the various hazard identification techniques, task analysis is one of the most important. The other techniques are discussed in subsequent chapters, but here discussions will be on task analysis. Task analysis is the study of what users need to do, in terms of actions and/or cognitive processes, to achieve a task objective. There are several factors, such as task duration, repetitive frequency, task allocation, complexity, equipment, ambience, and environmental conditions, which are required for the task and they very much influence the performance. At times, tasks are often used interchangeably with process. 

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