2We Will Cover:Machine Guarding PrinciplesSubpart O - HighlightsMock Plant Walk-Through
3Why are machines not guarded?No one would stick their arm, hand,finger, head, etc. in there.No one is supposed to be back there, inthere, around it while it is running.The machine came that way; it never hada guard.I’ve been doing it this way for twentyyears without any problems.
4Why are machines not guarded? (cont.)The guard is in the wayThe OSHA inspector didn’t say anythingabout it.We’ll put it back on if OSHA comes.
5Emphasis on Amputations :Where does it apply?General industry employerswhose workplaces include:shearssawsslicersslitterspower presses(the 4s and a P)
6Requirements for Safeguards Prevent contact - prevent worker’s body or clothingfrom contacting hazardous moving parts Secure - firmly secured to machine and not easilyremoved Protect from falling objects - ensure that no objects canfall into moving parts Create no new hazards - must not have shear points,jagged edges or unfinished surfaces Create no interference - must not prevent worker fromperforming the job quickly and comfortably Allow safe lubrication - if possible, be able to lubricatethe machine without removing the safeguards
7Where machine hazards occur:Point of operationMechanical power transmissionOther moving parts
16Fixed GuardProvides a barrier - a permanent part of themachine, preferable to all other types of guards.
17Interlocked GuardWhen this type of guard is opened or removed, thetripping mechanism and/or power automaticallyshuts off or disengages, and the machine cannotcycle or be started until the guard is back in place.Interlockedguard onrevolving drum
18Adjustable GuardProvides a barrier which may be adjusted tofacilitate a variety of production operations.Bandsaw bladeadjustable guard
19Self-Adjusting GuardProvides a barrier which moves according tothe size of the stock entering the danger area.Circular table sawself-adjusting guard
20Safeguarding devicesPresence sensingPullbackRestraintSafety controls and tripsGates
23Pullback Device Utilizes a series of cablesattached to the operator’shands, wrists, and/or arms Primarily used on machineswith stroking action Allows access to the point ofoperation when the slide/ramis up Withdraws hands when theslide/ram begins to descend
24Pullback Device (cont’d) Hands in die, feeding Point of operationexposed Pullback device attachedand properly adjusted Die closed Hands withdrawn frompoint of operation bypullback device
25Restraint Device Uses cables or strapsattached to the operator’shands and a fixed point Must be adjusted to let theoperator’s hands travelwithin a predeterminedsafe area Hand-feeding tools areoften necessary if theoperation involves placingmaterial into the dangerarea
26Safety Tripwire Cables Device located aroundthe perimeter of or nearthe danger area Operator must be able toreach the cable to stopthe machine
27Two-Hand Control Requires constant,concurrent pressure toactivate the machine The operator’s hands arerequired to be at a safelocation (on control buttons)and at a safe distance fromthe danger area while themachine completes itsclosing cycle
28Gate Movable barrier device which protects the operator at thepoint of operation before the machine cycle can be started If the gate does not fully close, machine will not functionGate Open Gate Closed
29Safeguarding by Location/Distance Locate the machine or itsdangerous moving partsso that they are notaccessible or do notpresent a hazard to aworker during normaloperation Maintain a safe distancefrom the danger area
30Automatic Feed(shown on power press)TransparentEnclosureGuardStock FeedRollDangerAreaCompleted Work
31Robots Machines that load andunload stock, assembleparts, transfer objects,or perform other tasks Best used in high-production processesrequiring repeatedroutines where theyprevent other hazards toemployees
32Protective ShieldsThese do not give complete protection frommachine hazards, but do provide some protectionfrom flying particles, splashing cutting oils, orcoolants.
33Holding ToolsUsed to place andremove stock in thedanger areaNot to be usedinstead of othermachine safeguards,but as a supplement
35Subpart O - Machinery and MachineGuarding211 - Definitions212 - General requirements213 - Woodworking machinery215 - Abrasive wheel machinery216 - Mills and calendars217 - Mechanical power presses218 - Forging machines219 - Mechanical power transmission
361910.212General Requirements for allMachines
371910.212(a)(1)One or more methods of machineguarding shall be provided to protect theoperator and other employees in themachine area from hazards such as thosecreated by the point of operation, in-going nip points, rotating parts, flyingchips and sparks.
381910.212(a)(3)(ii)The point of operation of machineswhose operation exposes an employee toinjury, shall be guarded
391910.212(a)(5)When the periphery of the blades of afan is less than seven (7) feet above thefloor or working level, the blades shall beguarded. The guard shall have openingsno larger than 1/2 inch.
401910.212(b)Machines designed for a fixed locationshall be securely anchored to preventwalking or moving.
421910.213(a)(9)All belts, pulleys, gears, shafts, andmoving parts shall be guarded inaccordance with the specificrequirements of 1910.219.
431910.213(b)(1)A mechanical or electrical power controlshall be provided on each machine tomake it possible for the operator to cutoff the power from each machine withoutleaving his position at the point ofoperation.
441910.213(b)(3) On applications whereinjury to the operatormight result if motorswere to restart afterpower failures, provisionshall be made to preventmachines fromautomatically restartingupon restoration ofpower.
461910.213(c)(1)Each circular hand-fed ripsaw shall beguarded by a hood which shallcompletely enclose that portion of thesaw above the table and that portion ofthe saw above the material being cut.The hood and mounting shall bearranged so that the hood willautomatically adjust itself to thethickness of and remain in contact withthe material being cut withoutconsiderable resistance.
471910.213(c)(2)Each hand-fed circular ripsaw shall befurnished with a spreader to preventmaterial from squeezing the saw or beingthrown back on the operator.
481910.213(c)(3)Each hand-fed circular ripsaw shall beprovided with non-kickback fingers ordogs so located as to oppose the thrust ortendency of the saw to pick up thematerial or throw it back toward theoperator.
491910.213(d)(1)Each circular crosscut table saw shall beguarded by a hood which shall meet allthe requirements of 1910.213(c)(1) forhoods for circular resaws.
50Radial Arm Saws
511910.213(i)(1)All portions of the saw blade (bandsaws)shall be enclosed or guarded, except forthe working portion of the blade betweenthe bottom of the guide rolls and thetable.
521910.213(r)(4)The mention of specific machines inparagraphs (a) thru (q) and thisparagraph (r) of this section, inclusive, isnot intended to exclude otherwoodworking machines from therequirements that suitable guards andexhaust hoods be provided to reduce to aminimum the hazard due to the point ofoperation of such machines.
531910.213(s)(7)All cracked saws shall be removed fromservice.
551910.215(a)(4)Work rests shall be adjusted closely tothe wheel with a maximum opening ofone-eighth inch to prevent the work frombeing jammed between the wheel and therest, which may cause wheel breakage.
561910.215(b)(9)The distance between the wheelperiphery and the adjustable tongue orthe end of the peripheral member at thetop shall never exceed one-fourth inch.
571910.215(d)(1)Immediately before mounting, all wheelsshall be closely inspected and sounded bythe user (ring test) to make sure theyhave not been damaged.
58Abrasive Wheel MachineryThe distance between the wheel periphery and theadjustable tongue must never exceed 1/4-inch.
591910.217Mechanical Power Presses
601910.217(a)(5)Press brakes, hydraulic and pneumaticpower presses, bulldozers, hot bendingand hot metal presses, forging pressesand hammers, riveting machines andsimilar types of fastener applicators areexcluded from the requirements of thissection.
611910.217(b)(4)The pedal mechanism shall be protectedto prevent unintended operation.A pad with a nonslip contact area shallbe firmly attached to the pedal.
621910.217(b)(6)A two-hand trip shall have the individualoperator’s hand controls protectedagainst unintended operation and bearranged to require use of both hands.Two-hand trip systems on full revolutionclutch machines shall incorporate anantirepeat feature.If two hand trip systems are used onmultiple operator systems, each operatorshall have a separate set of controls.
631910.217(b)(7)Two-hand controls must incorporate ananti repeat feature, require use of bothhands, be protected against unintendedoperation, have one set of controls foreach operator.If foot control is provided, the selectionbetween hand and foot control must besupervised by the employer.
641910.217(c)(1)It shall be the responsibility of theemployer to provide and insure the use ofpoint of operation guards or properlyapplied and adjusted point of operationdevices on every operation performed ona mechanical power press. See Table O-10.
651910.217(e)(1)It shall be the responsibility of theemployer to establish and follow aprogram of periodic and regularinspections of power presses.
661910.217(e)(3)It shall be the responsibility of theemployer to insure the original andcontinuing competence of personnelcaring for, inspecting, and maintainingpower presses.
681910.219(b)(1)Flywheels located so that any part is 7feet or less above the floor or platformshall be guarded.Wherever flywheels are above workingareas, guards shall be installed havingsufficient strength to hold the weight ofthe flywheel in the event of a shaft orwheel mounting failure.
691910.219(c)Horizontal, vertical, and inclinedshafting must be enclosed.Projecting shaft ends shall present asmooth edge and end and shall notproject more than 1/2 the diameter of theshaft unless guarded by non rotating capor safety sleeves.
701910.219(d)Pulleys 7ft. or less above the floor orplatform must be guarded.Pulleys with cracks or pieces broken outof rims shall not be used.
71Portable Power Tools - General SafetyPrecautions1910.242(a)Employers responsibilitySafe condition of toolsIncluding personal tools1910.242(b)Compressed air not used for cleaning exceptwhere reduced to less than 30 p.s.i. and onlywhen effective chip guarding and PPE.
72Power ToolsClassification by power sourceElectricPneumaticLiquid FuelHydraulicPowder Actuated
75Pneumatic Power Tools and Hose1910.243(b)Tool Retainer – A tool retainer must beinstalled on each piece of equipment whereejection could resultAirhose – Hose and hose connections mustbe designed for the pressure and service towhich they are subjected
76Explosive Actuated Fastening Tools1910.243(d)Must meet requirements in ANSI A10.3-1970Operators and assistants must wear eyeprotectionHead and face protection dependent onworking conditions
77Explosive Actuated Tools (Cont.)Muzzle must have protective shield orguard at least 3 ½ inches in diameter.Firing must be dependent on at least 2separate and distinct operations.Firing mechanism must prevent toolfrom firing during loading, whilepreparing, if dropped.
78Explosive Actuated Tools (Cont.)Tools must not be loaded until justbefore intended firing.Do not point at anyone!Fasteners not driven into hard/brittle oreasily penetrable materialTools not used in hazardous atmosphere
79Lawnmowers243(e)Meet the requirements of ANSI B71.1-X1968