Subpart O - Machinery and Machine Guarding

Subpart O provides the requirements for machinery and machine guarding.

Point of operations means that point at which cutting, shaping, boring, or forming is accomplished upon the stock.

Guard means a barrier that prevents entry of the operator's hands or fingers into the point of operation.

Types of guarding - One or more methods of machine guarding shall be provided to protect the operator and other employees in the machine area from hazards such as those created by point of operation, ingoing nip points, rotating parts, flying chips and sparks. Examples of guarding methods are - barrier guards, two-hand tripping devices, electronic safety devices, etc.

To learn if subpart O applies to you, go to Does "Subpart O - Machinery and Machine Guarding" Apply to You?

Special Requirements

Tab/Accordion Items

Scope: This standard provides the general requirements for all machines. 

Special Requirements: Design, references other standards

1910.212(a)(3)(ii) - 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 therefor, or, in the absence of applicable specific standards, 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.

Scope: This standard provides the requirements for woodworking machinery.

Special Requirements:  Marked, label, inspection, demonstrated skill, maintenance, references other standards

1910.213(a)(9) - All belts, pulleys, gears, shafts, and moving parts shall be guarded in accordance with the specific requirements of 1910.219 - mechanical power-transmission apparatus.

1910.213(h)(5) - Ripping and ploughing shall be against the direction in which the saw turns. The direction of the saw rotation shall be conspicuously marked on the hood. In addition, a permanent label not less than 1½ inches by ¾ inch shall be affixed to the rear of the guard at approximately the level of the arbor, reading as follows: "Danger: Do Not Rip or Plough From This End".

1910.213(s) - Inspection and maintenance of woodworking machinery. [Reference paragraph (s)(1) - (14)].

  • 1910.213(s)(5) - Sharpening or tensioning of saw blades or cutters shall be done only by persons of demonstrated skill in this kind of work.

Scope: This standard provides the requirements for abrasive wheel machinery.

Abrasive wheel means a cutting tool consisting of abrasive grains held together by organic or inorganic bonds. Diamond and reinforced wheels are included.

Special Requirements: Inspections, ring test, checks, taps, references other standards 

1910.215(b)(12) - Guard design specifications. Abrasive wheel machinery guards shall meet the design specifications of the American National Standard Safety Code for the Use, Care, and Protection of Abrasive Wheels, ANSI B7.1-1970, which is incorporated by reference as specified in 1910.6. This requirement shall not apply to natural sandstone wheels or metal, wooden, cloth, or paper discs, having a layer of abrasive on the surface.

1910.215(d)(1) - Inspection. Immediately before mounting, all wheels shall be closely inspected and sounded by the user (ring test) to make sure they have not been damaged in transit, storage, or otherwise. The spindle speed of the machine shall be checked before mounting of the wheel to be certain that it does not exceed the maximum operating speed marked on the wheel. Wheels should be tapped gently with a light nonmetallic implement, such as the handle of a screwdriver for light wheels, or a wooden mallet for heavier wheels. If they sound cracked (dead), they shall not be used. This is known as the “Ring Test”.

  • 1910.215(d)(1)(ii) - “Tap” wheels about 45° each side of the vertical centerline and about 1 or 2 inches from the periphery as indicated by the spots in Figure O-25 and Figure O-26. Then rotate the wheel 45° and repeat the test. A sound and undamaged wheel will give a clear metallic tone. If cracked, there will be a dead sound and not a clear “ring.”

Scope: This standard provides the requirements for mills and calendars used in the rubber and plastics industries.

Calender means a machine equipped with two or more metal rolls revolving in opposite directions and used for continuously sheeting or plying up rubber and plastics compounds and for frictioning or coating materials with rubber and plastics compounds.

Mill means a machine consisting of two adjacent metal rolls, set horizontally, which revolve in opposite directions (i.e., toward each other as viewed from above) used for the mechanical working of rubber and plastics compounds.

Special Requirements: References other standards 

1910.216(a)(3) - Auxiliary equipment. Mechanical and electrical equipment and auxiliaries shall be installed in accordance with this section and subpart S - electrical, of this part (1910).

Scope: This standard provides the requirements for mechanical power presses.

Press means a mechanically powered machine that shears, punches, forms or assembles metal or other material by means of cutting, shaping, or combination dies attached to slides. A press consists of a stationary bed or anvil, and a slide (or slides) having a controlled reciprocating motion toward and away from the bed surface, the slide being guided in a definite path by the frame of the press.

Special Requirements: Employer supervision, tests, design, inspections, checks, authorized personnel, maintenance, records (certification, maintenance, inspections), employer established limit, inspection program, stamped, employer responsibility, supervisor/safety engineer, diesetting procedures, instructions, training, operating procedures, injury reporting, certification, label, validation, manufacturer recommendations, references other standards 

1910.217(b)(7)(xv) - Selection of bar operation shall be by means capable of being supervised by the employer. A separate pushbutton shall be employed to activate the clutch, and the clutch shall be activated only if the driver motor is deenergized.

1910.217(b)(12) - Pressure vessels. All pressure vessels used in conjunction with power presses shall conform to the American Society of Mechanical Engineers Code for Pressure Vessels, 1968 Edition, which is incorporated by reference as specified in 1910.6.

1910.217(b)(13) - Control reliability. When required by paragraph (c)(5) of this section, the control system shall be constructed so that a failure within the system does not prevent the normal stopping action from being applied to the press when required, but does prevent initiation of a successive stroke until the failure is corrected. The failure shall be detectable by a simple test, or indicated by the control system. This requirement does not apply to those elements of the control system which have no effect on the protection against point of operation injuries.

1910.217(b)(14)(i) - Be so constructed as to automatically prevent the activation of a successive stroke if the stopping time or braking distance deteriorates to a point where the safety distance being utilized does not meet the requirements set forth in paragraph (c)(3)(iii)(e) or (c)(3)(vii)(c) of this section. The brake monitor used with the Type B gate or movable barrier device shall be installed in a manner to detect slide top-stop overrun beyond the normal limit reasonably established by the employer.

1910.217(c)(1)(i) - It shall be the responsibility of the employer to provide and insure the usage of "point of operation guards" or properly applied and adjusted point of operation devices on every operation performed on a mechanical power press. See Table O-10.

1910.217(c)(2)(i) - Every point of operation guard shall meet the following design, construction, application, and adjustment requirements: [Reference paragraph (c)(2)(i)(a) - (f)].

1910.217(c)(2)(vi) - The adjustable barrier guard shall be securely attached to the press bed, bolster plate, or die shoe, and shall be adjusted and operated in conformity with Table O-10 and the requirements of this subparagraph. Adjustments shall be made only by authorized personnel whose qualifications include a knowledge of the provisions of Table O-10 and this subparagraph.

1910.217(c)(3)(iv)(d) - Each pull-out device in use shall be visually inspected and checked for proper adjustment at the start of each operator shift, following a new die set-up, and when operators are changed. Necessary maintenance or repair or both shall be performed and completed before the press is operated. Records of inspections and maintenance shall be kept in accordance with paragraph (e) of this section.

1910.217(c)(3)(viii)(d) - Two hand trips shall be fixed in position so that only a supervisor or safety engineer is capable of relocating the controls.

1910.217(d)(3) - Scrap handling. The employer shall provide means for handling scrap from roll feed or random length stock operations. Scrap cutters used in conjunction with scrap handling systems shall be safeguarded in accordance with paragraph (c) of this section and with 1910.219 - mechanical power-transmission apparatus.

1910.217(d)(6) - Tonnage, stroke, and weight designation. All dies shall be:

  • 1910.217(d)(6)(i) - Stamped with the tonnage and stroke requirements, or have these characteristics recorded if these records are readily available to the die setter;
  • 1910.217(d)(6)(ii) - Stamped to indicate upper die weight when necessary for air counterbalance pressure adjustment; and
  • 1910.217(d)(6)(iii) - Stamped to indicate complete die weight when handling equipment may become overloaded.

1910.217(d)(9)(i) - The employer shall establish a diesetting procedure that will insure compliance with paragraph (c) of this section.

1910.217(e)(1) - Inspection and maintenance records. The employer shall establish and follow an inspection program having a general component and a directed component. [Reference paragraph (e)(1)(i) - (iii)].
 
1910.217(e)(2) - Modification. It shall be the responsibility of any person modifying a power press to furnish instructions with the modification to establish new or changed guidelines for use and care of the power press so modified.
 
1910.217(e)(3) - Training of maintenance personnel. It shall be the responsibility of the employer to insure the original and continuing competence of personnel caring for, inspecting, and maintaining power presses.
 
1910.217(f)(2) - Instruction to operators. The employer shall train and instruct the operator in the safe method of work before starting work on any operation covered by this section. The employer shall insure by adequate supervision that correct operating procedures are being followed.
 

1910.217(g)(1) - The employer shall report, within 30 days of the occurrence, all point-of-operation injuries to operators or other employees to either the Director of the Directorate of Standards and Guidance at OSHA, U.S. Department of Labor, Washington, DC 20210 or electronically at http://www.osha.gov/pls/oshaweb/mechanical.html; or to the State Agency administering a plan approved by the Assistant Secretary of Labor for Occupational Safety and Health.

1910.217(g)(2) - The report shall include the following information: [Reference paragraph (g)(2)(i) - (viii)].

1910.217(h)(5)(i) - Presses operated in the PSDI mode shall be equipped with a brake monitor that meets the requirements of paragraphs (b)(13) and (b)(14) of this section. In addition, the brake monitor shall be adjusted during installation certification to prevent successive stroking of the press if increases in stopping time cause an increase in the safety distance above that required by paragraph (h)(9)(v) of this section.

1910.217(h)(5)(ii) - Once the PSDI safety system has been certified/validated, adjustment of the brake monitor shall not be done without prior approval of the validation organization for both the brake monitor adjustment and the corresponding adjustment of the safety distance. The validation organization shall in its installation validation, state that in what circumstances, if any, the employer has advance approval for adjustment, when prior oral approval is appropriate and when prior approval must be in writing. The adjustment shall be done under the supervision of an authorized person whose qualifications include knowledge of safety distance requirements and experience with the brake system and its adjustment. When brake wear or other factors extend press stopping time beyond the limit permitted by the brake monitor, adjustment, repair, or maintenance shall be performed on the brake or other press system element that extends the stopping time.

1910.217(h)(6)(vi) - The control system shall incorporate a timer to deactivate PSDI when the press does not stroke within the period of time set by the timer. The timer shall be manually adjustable, to a maximum time of 30 seconds. For any timer setting greater than 15 seconds, the adjustment shall be made by the use of a special tool available only to authorized persons. Following a deactivation of PSDI by the timer, the system shall make it necessary to reset the set-up/reset means in order to reactivate the PSDI mode.

1910.217(h)(9)(vii) - Where presence sensing device location is adjustable, adjustment shall require the use of a special tool available only to authorized persons.

1910.217(h)(10) - Inspection and maintenance.

  • 1910.217(h)(10)(i) - Any press equipped with presence sensing devices for use in PSDI, or for supplemental safeguarding on presses used in the PSDI mode, shall be equipped with a test rod of diameter specified by the presence sensing device manufacturer to represent the minimum object sensitivity of the sensing field. Instructions for use of the test rod shall be noted on a label affixed to the presence sensing device.

1910.217(h)(10)(iii) - When presses used in the PSDI mode have flywheel or bullgear running on crankshaft mounted journals and bearings, or a flywheel mounted on back shaft journals and bearings, periodic inspections following the press manufacturer's recommendations shall be made to ascertain that bearings are in good working order, and that automatic lubrication systems for these bearings (if automatic lubrication is provided) are supplying proper lubrication. On presses with provision for manual lubrication of flywheel or bullgear bearings, lubrication shall be provided according to the press manufacturer's recommendations. 

1910.217(h)(10)(iv) - Periodic inspections of clutch and brake mechanisms shall be performed to assure they are in proper operating condition. The press manufacturer's recommendations shall be followed. 
 
1910.217(h)(10)(v) - When any check of the press, including those performed in accordance with the requirements of paragraphs (h)(10)(ii), (iii) or (iv) of this section, reveals a condition of noncompliance, improper adjustment, or failure, the press shall not be operated until the condition has been corrected by adjustment, replacement, or repair.
 

1910.217(h)(10)(vi) - It shall be the responsibility of the employer to ensure the competence of personnel caring for, inspecting, and maintaining power presses equipped for PSDI operation, through initial and periodic training.

1910.217(h)(11)(i) - Prior to the initial use of any mechanical press in the PSDI mode, two sets of certification and validation are required: [Reference paragraph (h)(11)(i)(A) - (B)].
 

1910.217(h)(11)(ii) - At least annually thereafter, the safety system on a mechanical power press used in the PSDI mode shall be recertified by the employer and revalidated by an OSHA-recognized third-party validation organization to meet all applicable requirements of paragraphs (a) through (h) and appendix A - trajectory, of this section. Any press whose safety system has not been recertified and revalidated within the preceding 12 months shall be removed from service in the PSDI mode until the safety system is recertified and revalidated.

1910.217(h)(11)(iii) - A label shall be affixed to the press as part of each installation certification/validation and the most recent recertification/revalidation. The label shall indicate the press serial number, the minimum safety distance (Ds) required by paragraph (h)(9)(v) of this section, the fulfillment of design certification/validation, the employer's signed certification, the identification of the OSHA-recognized third-party validation organization, its signed validation, and the date the certification/validation and recertification/revalidation are issued.

1910.217(h)(11)(iv) - Records of the installation certification and validation and the most recent recertification and revalidation shall be maintained for each safety system equipped press by the employer as long as the press is in use. The records shall include the manufacture and model number of each component and subsystem, the calculations of the safety distance as required by paragraph (h)(9)(v) of this section, and the stopping time measurements required by paragraph (h)(2)(ii) of this section. The most recent records shall be made available to OSHA upon request.

1910.217(h)(11)(v) - The employer shall notify the OSHA-recognized third-party validation organization within five days whenever a component or a subsystem of the safety system fails or modifications are made which may affect the safety of the system. The failure of a critical component shall necessitate the removal of the safety system from service until it is recertified and revalidated, except recertification by the employer without revalidation is permitted when a non-critical component or subsystem is replaced by one of the same manufacture and design as the original, or determined by the third-party validation organization to be equivalent by similarity analysis, as set forth in appendix A - trajectory.

1910.217(h)(11)(vi) - The employer shall notify the OSHA-recognized third-party validation organization within five days of the occurrence of any point of operation injury while a press is used in the PSDI mode. This is in addition to the report of injury required by paragraph (g) of this section; however, a copy of that report may be used for this purpose.

1910.217(h)(12)(iii) - Following a die change, the safety distance, the proper application of supplemental safeguarding, and the slide counterbalance adjustment (if the press is equipped with a counterbalance) shall be checked and maintained by authorized persons whose qualifications include knowledge of the safety distance, supplemental safeguarding requirements, and the manufacturer's specifications for counterbalance adjustment. Adjustment of the location of the PSDI presence sensing device shall require use of a special tool available only to the authorized persons. 
 
1910.217(h)(13)(i) - The operator training required by paragraph (f)(2) of this section shall be provided to the employee before the employee initially operates the press and as needed to maintain competence, but not less than annually thereafter. It shall include instruction relative to the following items for presses used in the PSDI mode. [Reference paragraph (h)(13)(i)(A) - (E)].
 
1910.217(h)(13)(ii) - The employer shall certify that employees have been trained by preparing a certification record which includes the identity of the person trained, the signature of the employer or the person who conducted the training, and the date the training was completed. The certification record shall be prepared at the completion of training and shall be maintained on file for the duration of the employee's employment. The certification record shall be made available upon request to the Assistant Secretary for Occupational Safety and Health.

 

 

Scope: This standard provides the requirements for forging machines.

Forging means the product of work on metal formed to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. Forging hammers, counterblow equipment and high-energy-rate forging machines impart impact to the workpiece, while most other types of forging equipment impart squeeze pressure in shaping the stock. Some metals can be forged at room temperature, but the majority of metals are made more plastic for forging by heating.

Special Requirements: Inspections, maintenance, signatures, records, scheduling, certification record, training, engineering standards, specifications, locking out, switches identifiable, references other standards

1910.218(a)(2) - Inspection and maintenance. It shall be the responsibility of the employer to maintain all forge shop equipment in a condition which will insure continued safe operation. This responsibility includes:

  • 1910.218(a)(2)(i) - Establishing periodic and regular maintenance safety checks and keeping certification records of these inspections which include the date of inspection, the signature of the person who performed the inspection and the serial number, or other identifier, for the forging machine which was inspected.
  • 1910.218(a)(2)(ii) - Scheduling and recording the inspection of guards and point of operation protection devices at frequent and regular intervals. Recording of inspections shall be in the form of a certification record which includes the date the inspection was performed, the signature of the person who performed the inspection and the serial number, or other identifier, of the equipment inspected.
  • 1910.218(a)(2)(iii) - Training personnel for the proper inspection and maintenance of forging machinery and equipment.

1910.218(a)(3)(i) - All hammers shall be positioned or installed in such a manner that they remain on or are anchored to foundations sufficient to support them according to applicable engineering standards.

1910.218(a)(3)(ii) - All presses shall be installed in such a manner that they remain where they are positioned or they are anchored to foundations sufficient to support them according to applicable engineering standards.

1910.218(a)(3)(iii) - Means shall be provided for disconnecting the power to the machine and for locking out or rendering cycling controls inoperable.

1910.218(a)(3)(iv) - The ram shall be blocked when dies are being changed or other work is being done on the hammer. Blocks or wedges shall be made of material the strength and construction of which should meet or exceed the specifications and dimensions shown in Table O-11.

1910.218(d)(4) - Pressure pipes. Steam or air piping shall conform to the specifications of American National Standard ANSI B31.1.0-1967, Power Piping with Addenda issued before April 28, 1971, which is incorporated by reference as specified in 1910.6.

1910.218(e)(1)(iv) - Air piping shall conform to the specifications of the ANSI B31.1.0-1967, Power Piping with Addenda issued before April 28, 1971, which is incorporated by reference as specified in 1910.6.

1910.218(f)(1) - Mechanical forging presses. When dies are being changed or maintenance is being performed on the press, the following shall be accomplished:

1910.218(f)(2) - Hydraulic forging presses. When dies are being changed or maintenance is being performed on the press, the following shall be accomplished:

  • 1910.218(f)(2)(i) - The hydraulic pumps and power apparatus shall be locked out.
  • 1910.218(f)(2)(ii) - The ram shall be blocked with a material the strength of which shall meet or exceed the specifications or dimensions shown in Table O-11.

1910.218(g)(2) - Cold trimming presses. Cold trimming presses shall be safeguarded in accordance with 1910.217(c) - mechanical power presses.

1910.218(h)(2) - Lockouts. Upsetters shall be provided with a means for locking out the power at its entry point to the machine and rendering its cycling controls inoperable.

1910.218(h)(3) - Manually operated controls. All manually operated valves and switches shall be clearly identified and readily accessible.

1910.218(h)(5) - Changing dies. When dies are being changed, maintenance performed, or any work done on the machine, the power to the upsetter shall be locked out, and the flywheel shall be at rest.

1910.218(j)(3) - Conveyors. Conveyor power transmission equipment shall be guarded in accordance with ANSI B20.1-1957, Safety Code for Conveyors, Cableways, and Related Equipment, which is incorporated by reference as specified in 1910.6.

1910.218(j)(5) - Grinding. Personal protective equipment shall be used in grinding operations, and equipment shall be used and maintained in accordance with ANSI B7.1-1970, Safety Code for the Use, Care, and Protection of Abrasive Wheels, which is incorporated by reference as specified in 1910.6, and with 1910.215 - abrasive wheel machinery.

 

 

Scope: This standard provides the requirements for safeguards for all types and shapes of power-transmission belts, pulleys, ropes, gears, sprockets, chains, projections (keys, setscrews), clutches, collars, couplings, fasteners, and other similar moving parts.

Special Requirements: Manufacturer recommendations, designed, inspections, references other standards

1910.219(c)(5)(iii) - The intensity of illumination conforms to the requirements of ANSI A11.1-1965 (R-1970), which is incorporated by reference as specified in 1910.6.

1910.219(d)(4) - Pulley speeds. Pulleys intended to operate at rim speed in excess of manufacturers normal recommendations shall be specially designed and carefully balanced for the speed at which they are to operate.

1910.219(p)(1) - General. All power-transmission equipment shall be inspected at intervals not exceeding 60 days and be kept in good working condition at all times.

1910.219(p)(4) - Hangers. Hangers shall be inspected to make certain that all supporting bolts and screws are tight and that supports of hanger boxes are adjusted properly.

1910.219(p)(6)(ii) - Inspection shall be made of belts, lacings, and fasteners and such equipment kept in good repair.

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