1.0 PURPOSE
The purpose of this procedure is to provide written instructions for Nitro Construction Services for the proper use and maintenance of hand tools, power tool guards to eliminate hazards relative to points of operation, nip points, rotating parts, flying chips, and sparks.
2.0 RESPONSIBILITY
It is the responsibility of the Site Manager/Superintendent to implement the requirements of this procedure.
3.0 REFERENCES
29 CFR 1910 Subpart P
29 CFR 1926 Subpart I
4.0 DEFINITIONS
4.1 Flange – A collar, disc, or plate between or against which wheels are mounted and are referred to as adaptor sleeve, straight relieved, or straight unrelieved type. The flange disseminates the driving torque of the spindle to the spindle to the grinding wheel and assists in maintaining the integrity of the wheel.
4.1 Point of Operation – The area on a machine where work is performed upon the material being processed.
4.2 Portable Grinder – A grinding operation where the grinding machine is designed to be handheld and may be easily moved from one location to another.
4.3 Safety Guard – A safety guard is an enclosure designed to restrain the pieces of the grinding wheel and furnish all possible protection if the wheel is broken in operation.
4.4 Type 11 flaring cup wheels – Type 11 flaring cup wheels have double dimensions D and J, and also have a thickness, hole size, rim, and back thickness dimensions. Grinding is always performed on rim face, W dimension.
4.5 Type 6 straight cup wheels – Type 6 cup wheels have a diameter, thickness, hole size, rim thickness, and back thickness dimensions. Grinding is always performed on rim face, W dimension.
5.0 PROCEDURE
5.1 All hand and power tools and similar equipment, whether furnished by the employer or employee, shall be maintained in a safe condition.
5.2 Any tool which is not in compliance or found to be deficient shall not be used and shall be identified as unsafe by tagging or locking the controls to render them inoperable.
5.3 When powered operated tools are designed to accommodate guards, they shall be equipped with such guards when in use.
5.4 The point of operation of machines whose operation exposes an employee to injury, shall be guarded. The guarding device shall be in conformity with any appropriate standards and shall be so designed and constructed as to prevent the operator from having any part of his body in the danger zone during the operating cycle.
5.5 Compressed air shall not be used for cleaning purposes except where reduced to 30 p.s.i. and then only with effective chip guarding and personal protective equipment.
5.6 Electrical Power-Operated Tools
5.6.1 All electrical tools shall be of the approved double-insulated type or provide electrical service through ground fault circuit interrupters and an assured grounding system to protect employees from electrical shock due to a tool defect.
5.6.2 The use of electric cords for hoisting or lowering tools shall not be permitted.
5.7 Pneumatic Powered Tools And Hoses
5.7.1 A tool retainer shall be installed on each piece of equipment, which, without such a retainer, may eject the tool.
5.7.2 Hose and hose connections used for conducting compressed air to pneumatic equipment shall be designed for the pressure and service to which they are subjected.
5.7.3 The hose shall be secured to the power tool by some positive means to prevent the hose from becoming accidentally disconnected.
5.7.4 Hose connections shall be secured with a pin or wire.
5.7.5 All hoses exceeding ½ inch inside diameter shall have a safety device at the source of supply or branch line to reduce pressure in case of hose failure.
5.7.6 All pneumatically driven nails, staplers, and other similar equipment provided with an automatic fastener feed, which operates at more than 100 psi pressure at the tool, shall have a safety device on the muzzle, to prevent the tool from ejecting fasteners, unless the muzzle is in contact with the work surface.
5.7.7 Compressed air shall not be used for cleaning purposes except where reduced to 30 psi with effective chip guarding and appropriate PPE.
5.7.8 Airless spray guns of the type which atomize paints and fluids at high pressures (1,000 psi or more) shall be equipped with automatic or visible manual safety devices which will prevent pulling of the trigger to prevent the release of the paint or fluid until the safety device is manually released.
5.7.9 Pneumatic powered drills and grinders shall be guarded in the same manner as those powered by electricity.
5.8 Portable Abrasive Wheels
5.8.1 All grinding machines shall be supplied with sufficient power to maintain the spindle speed at safe levels under all conditions of normal operation.
5.8.2 Immediately before mounting, all wheels shall be closely inspected and sounded by the user (ring test) to make sure they are not damaged. The spindle speed of the machine shall be checked before the mounting of the wheel to be certain that it does not exceed the maximum operating speed marked on the wheel.
5.8.3 Grinding wheels shall fit freely on the spindle and remain free under all grinding conditions. A controlled clearance between the wheel hole and the machine spindle is essential to avoid excessive pressure from mounting and spindle expansion.
5.8.4 All contact surfaces of wheels, blotters, and flanges shall be flat and free of foreign matter.
5.8.5 When a bushing is used in the wheel hole it shall not exceed the width of the wheel and shall not contact the flanges.
5.8.6 All employees using abrasive wheels shall wear appropriate eye protection.
5.8.7 Guards for portable abrasive wheels used for external grinding shall be so mounted as to maintain proper alignment with the wheel, and the guard and its fastenings shall be of sufficient strength to retain fragments of the wheel in case of accidental breakage.
5.8.8 General precautions when using flanges follow:
5.8.8.1 Ensure both flanges are of equal diameter.
5.8.8.2 Do not use washers in place of flanges.
5.8.8.3 Ensure flanges have proper clearance or relief.
5.8.8.4 Do not overtighten flanges causing them to bend.
5.8.8.5 Clean all dirt and foreign material from sides of wheels and flanges.
5.8.8.6 Check that flange diameter is no less than 1/3 wheel diameter and is preferably made of mild steel.
5.8.9 Cup wheels (Types 6 and 11) shall be protected by fixed guards that mount behind the wheel and are attached to the housing of the grinder.
5.8.10 Vertical Portable Grinders – Safety guards used on machines known as right angle head or vertical portable grinders shall have a maximum exposure angle of 180 degrees, and the guard shall be so located as to be between the operator and the wheel during use. Adjustment of the guard shall be such that pieces of an accidentally broken wheel will be deflected away from the operator.
5.8.11 Other Portable Grinders – The maximum angular exposure of the grinding wheel periphery and sides for safety guards used on other portable grinding machines shall not exceed 180 degrees, and the top half of the wheel shall be enclosed at all times.
5.8.12 Work rests shall be used to support the work on offhand grinding machines.
5.8.12.1 Work rests shall be of rigid construction and designed to be adjustable to compensate for wheel wear.
5.8.12.2 Work rests shall be kept adjusted closely to the wheel with a maximum opening of 1/8 inch to prevent the work from being jammed between the wheel and the rest, which may cause wheel breakage.
5.8.12.3 The work rest shall be securely clamped after each adjustment. The adjustment shall not be made with a wheel in motion.
5.9 Portable Belt Sanding Machines
5.9.1 Belt sanding machines shall be provided with guards at each nip point where the sanding belt runs onto a pulley.
5.9.2 These guards shall prevent the hands and fingers of the operator from coming in contact with the nip points.
5.9.3 The unused run of the sanding belt shall also be guarded against accidental contact.
5.10 Portable Circular Saws
5.10.1 All portable, power-driven circular saws having a blade diameter greater than 2 inches shall be equipped with guards above and below the base plate or shoe.
5.10.2 The upper guard shall cover the saw to the depth of the teeth, except for the minimum arc required to permit the base to be tilted for bevel cuts.
5.10.3 The lower guard shall cover the saw to the depth of the teeth, except for the minimum arc required to allow proper retraction and contact with the work.
5.10.4 When the tool is withdrawn from the work, the lower guard shall automatically and instantly return to the covering position.
5.10.5 All hand-held powered circular saws having a blade diameter greater than 2 inches, electric, hydraulic or pneumatic chain saws, and percussion tools without positive accessory holding means shall be equipped with a constant pressure switch or control that will shut off the power when the pressure is released.
5.11 Portable Band Saws
5.11.1 Guards shall be provided at each pulley and extend along the non-cutting portion of the band saw.
5.11.2 Proper hand position is imperative since a guard is not feasible along the cutting portion.
5.11.3 Both hands are necessary to handle this type saw and should be placed into the corresponding handles.
5.12 Other Tools
5.12.1 Tools such as electric drills, saber saws, and portable routers are not compatible with guards due to their physical characteristics in conjunction with their function.
5.12.2 Proper usage, with special emphasis on hand position, is the primary accident-preventative measure.
5.13 Gas Welding And Burning Equipment
5.13.1 All gas welding and burning equipment shall be provided with flashback arrestors at the handle and at the gauge to preclude the possibility of ignition of gas within the hose.
5.14 Utility/Knife Use
5.14.1 For all use of knives, the specific job tasks shall be evaluated and assessed for the use of self-retracting utility knives or cutting devices that guard against exposure to an open blade as the only authorized knife to protect from unintentional cuts.
5.14.2 A knife or any other unprotected blade tool must be the last resort when choosing a cutting tool.
5.14.3 Ensure that hand knives are the most practical tool for the task. Where possible use the safest cutting tool for the job (e.g. scissors, snips, or wire strippers).
5.14.4 If the knife happens to be the correct tool, keep the knife sharp and clean. A dull blade can cause accidents because more force is needed to cut an object.
5.14.5 Have a supply of either replacement knives and/or blades and make them readily available.
5.14.6 Cut away from yourself, ending the knife stroke away from your body. Hold the item you’re cutting firmly, and don’t cut downwards and towards your body. Cut into the air or onto something hard.
5.14.7 Confirm that appropriate PPE specific to the task is available to employees and mandate the use of Kevlar (minimum cut protection of level 3) gloves and sleeves when the possibility of injury exists.
5.14.8 Personal knives (e.g. pocket knives) shall not be considered as a tool for any type of work-related cutting.
5.15 Training And Maintenance
5.15.1 Employees must be trained as to why guards are necessary and how to properly use whatever guards are needed.
5.15.2 Follow-up measures in the form of proper supervision, regular inspections, and accident investigations are necessary to assure that machine guarding regulations and practices comply.