Document MJBBZ73pk2pVg8a2XpGJ4Qr3M

1910.331 STANDARDS AND INTERPRETATIONS OCCUPATIONAL SAFETY AND HEALTH 1910.331--SAFETY-RELATED WORK PRACTICES (a) Scope. Covered work by both qualified and unqualified persons. The provisions of 1910.331 through 1910.335, cover electrical safety-related work practices for both qualified persons (those who have training in avoiding the electrical haz ards of working on or near exposed energized parts) and unqualified persons (those with little or no such training) working on, near, or with the fol lowing installations: >; (1) Premises wiring. Installations of electric con ductors and equipment within or on buildings or other structures, and on other premises such as yards, carnival, parking, and other lots, and industrial substations; (2) Wiring for connection to supply. Installations of conductors that connect to the supply of electricity; and (3) Other wiring. Installations of other outside conductors on the premises. (4) Optical fiber cable. Installations of optical fiber cable where such installations are made along with electric conductors. NOTE: See 1910.399 for the definition of "qualified person." See 1910.332 for training requirements that apply to qualified and un qualified persons. (b) Other covered work by unqualified persons. The provisions of 1910.331 through 1910.335 also cover work performed by unqualified persons on, near, or with the installations listed in paragraphs (c) (1) through (c)(4) of this section. (c) Excluded work by qualified persons. The provi sions of 1910.331 through 1910.335 do not apply to work performed by qualified persons on or directly associated with the following installations: (1) Generation, transmission, and distribution installations. Installations for the generation, control, transformation, transmission, and dis tribution of electric energy (including communi cation and metering) located in buildings used for such purposes or located outdoors. NOTE 1: Work on or directly associated with installations of utilization equipment used for purposes other than generating, transmitting, or distributing electric energy (such as installa tions which are in office buildings, warehouses, garages, machine shops, or recreational build ings, or other utilization installations which are not an integral part of a generating installation, substation, or control center) is covered under paragraph (a)(1) of this section. 'i NOTE 2: Work on or directly associated with generation, transmission, or distribution in stallations includes: (1) Work performed directly on such installa tions, such as repairing overhead or under ground distribution lines or repairing a feedwater pump for the boiler in a generating plant. (2) Work directly associated with such in stallations, such as line-clearance tree trim ming and replacing utility poles. (3) Work on electric utilization circuits in a generating plant provided that: (a) Such circuits are commingled with installations of power generation equipment or circuits, and (b) The generation equipment or circuits present greater electrical hazards than those posed by the utilization equipment or circuits (such as exposure to higher voltages or lack of overcurrent protection). (2) Communications installations. Installations of communication equipment to the extent that the work is covered under 1910.268. (3) Installations in vehicles. Installations in ships, watercraft, railway rolling stock, aircraft, or automotive vehicles other than mobile homes and recreational vehicles. (4) Railway installations. Installations of rail ways for generation, transformation, transmis sion, or distribution of power used exclusively for operation of rolling stock or installations of railways used exclusively for signaling and com munication purposes. 1910.331(c)(4) 694.0.24.2 Change 56 ) ) SHINTECH-000514 \7r'vT<.,'4ji7crvTT'i's/\'*?v>7*7Tnnr*7Vom'ir,,r.*r*ui.oriwoe--* OCCUPATIONAL SAFETY AND HEALTH metal sheath of aerial cables entering buildings shall be grounded or shall be inter rupted close to the entrance to the building by an insulating joint or equivalent device. Where protective devices are used, they shall be grounded in an approved manner. (ii) Antenna structures. Masts and metal structures supporting antennas shall be permanently and effectively grounded with-/ out splice or connection in the grounding conductor. 1910.308(e)(5)(i) STANDARDS AND INTERPRETATIONS (iii)/fequipment enclosures. Transmitters shall be enclosed in a metal frame or grill or sarated from the operating space by a irrier/all metallic parts of which are effec tively connected to ground. AH external metal handles and controls accessible to the operating personnel shall be effectively grounded. Unpowered equipment and enclo sures shall be considered grounded where connected to an attached coaxial cable with an effectively grounded metallic shield. 1910.309-^1910.330 [Reserved] Safety-Related Work\ Practices Change 56 694.0.24.1 1910.309-330 SHINTECH-000515 OCCUPATIONAL SAFETY AND HEALTH 1910.332(a) STANDARDS AND INTERPRETATIONS 1910.332--Training (a) Scope. The training requirements contained in this section apply to employees who face a risk of electric shock that is not reduced to a safe level by the electrical installation require ments of 1910.303 through 1910.308. NOTE: Employees in occupations listed in Table S-4 face such a risk and are required to be trained. Other employees who also may reason ably be expected to face a comparable risk of injury due to electric chock or other electrical * hazards must also be trained. (b) Content of training. (1) Practices addressed in this standard. Em ployees shall be trained in and familiar with the safety-related work practices required by 1910.331 through 1910.335 that pertain to their respective job assignments. (2) Additional requirements for unqualified per sons. Employees who are covered by paragraph (a) of this section but who are not qualified per sons shall also be trained in and familiar with any electrically related safety practices not spe cifically addressed by 1910.331 through 1910.335 but which are necessary for their safety. (3) Additional requirements for qualified persons. Qualified persons (i.e., those permitted to work on or near exposed energized parts) shall, at a minimum, be trained in and familiar with the following. (i) The skills and techniques necessary to distinguish exposed live parts from other parts of electric equipment, (ii) The skills and techniques necessary to determine the nominal voltage of exposed live parts, and (iii) The clearance distances specified in 1910.333(c) and the corresponding volt ages to which the qualified person will be exposed. NOTE 1: For the purpose of 1910.331 through 1910.335, a person must have the training required by paragraph (b)(3) of this section in order to be considered a qualified persori. NOTE 2: Qualified persons whose work on energized equipment involves either direct contact or contact by means of tools or materials must also have the training needed to meet 1910.333(c)(2). (c) Type of training. The training required by this section shall be of the classroom or on-the-job type. The degree of training provided shall be determined by the risk to the employee. TABLE S-4.--TYPICAL OCCUPATIONAL CATEGORIES OF .EMPLOYEES FACING A HIGHER THAN NORMAL RISK OF Electrical accident Occupation Blue collar supervisors.1 Electrical and electronic engineers.1 Electrical and electronic equipment assemblers.1 Electrical and electronic technicians.1 Electricians. Industrial machine operators.' Material handling equipment operators.' Mechanics and repoirers.' Painters. ` Riggers and roustabouts.1 Stationary engineers.' Welders. 'Workers in these groups do not need to be trained if their work or the work of those they supervise does not bring them or the employees they supervise close enought to exposed parts of electric circuits operating at 50 volts or more to ground for a hastord to exist. 1910.333--Selection and use of work practices. (a) General. Safety-related work practices shall be employed to prevent electric shock or other inju ries resulting from either direct or indirect electri cal contacts, when work is performed near or on equipment or circuits which are or may be ener gized. The specific safety-related work practices shall be consistent with the nature and extent of the associated electrical hazards. Change 56 ' 694.0.24.3 1910.333(a) SHINTECH-000516 1910.333(a)(i) STANDARDS AND INTERPRETATIONS OCCUPATIONAL SAFETY AND HEALTH (1) Deenergized parts. Live parts to which an employee may be exposed shall be deenergized before the employee works on or near them, unless the employer can demonstrate that deen ergizing introduces additional or increased haz ards or is infeasible due to equipment design or operational limitations. Live parts that operate at less than 50 volts to ground need not be deen ergized if there will be no increased exposure to electrical burns or to explosion due to electric arcs. NOTE 1: Examples of increased or additional hazards include interruption of life support equipment, deactivation of emergency alarm systems, shutdown of hazardous location venti lation equipment, or removal of illumination for an area. NOTE 2: Examples of work that may be per formed on or near energized circuit parts because of infeasibility due to equipment design or operational limitations include testing of electric circuits that can only be performed with the circuit energized and work on circuits that form an integral part of a continuous industrial process in a chemical plant that would otherwise need to be completely shut down in order to per mit work on one circuit or piece of equipment. NOTE 3: Work on or near deenergized parts is covered by paragraph (b) of this section. (2) Energized parts. If the exposed live parts are not deenergized (i.e., for reasons of increased or additional hazards or infesibility), other safetyrelated work practices shall be used to protect employees who may be exposed to the electrical hazards involved. Such work practices shall pro tect employees against contact with energized circuit parts directly with any part of their body or indirectly through some other conductive object. The work practices that are used shall be suitable for the conditions under which the work is to be performed and for the voltage level of the exposed electric conductors or circuit parts. Specific work practice requirements are detailed in paragraph (c) of this section. (b) Working on or near exposed deenergized parts.1 (1) Application. This paragraph applies to work on exposed deenergized parts or near enough to them to expose the employee to any electrical hazard they present. Conductors and parts of electric equipment that have been deenergized but have not been locked out or tagged in accordance with paragraph (b) of this section shall be treated as energized parts, and para graph (c) of this section applies to work on or near them. (2) Lockout and tagging. While any employee is exposed to contact with parts of fixed electric equipment or circuits which have been deen ergized, the circuits energizing the parts shall be locked out or tagged or both in accordance with the requirements of this paragraph. The requirements shall be followed in the order in which they are presented (i.e., paragraph (bX2)(i) first, then paragraph (b)(2)(ii), etc.). NOTE 1; As used in this section, fixed equipment refers to equipment fastened in place or con nected by permanent wiring methods. NOTE 2: Lockout and tagging procedures that comply with paragraphs (c) through (f) of 1910.147 will also be deemed to comply with paragraph (b)(2) of this section provided that: (1) The procedures address the electrical safety hazards covered by this Subpart; and (2) The procedures also incorporate the require ments of paragraphs (b)(2)(iii)(D) and (b)(2) (iv)(B) of this section. (i) Procedures. The employer shall maintain a copy of the procedures outlined in paragraph (b)(2) and shall make it available for in spection by employees and by the Assistant Secretary of Labor and his or her authorized representatives. NOTE: The written procedures may be in the form of a copy of paragraph (b) of this section. (ii) Deenergizing equipment. (a) Safe procedures for deenergizing circuits and equipment shall be determined before cir cuits or equipment are deenergized. (b) The circuits and equipment to be worked on shall be disconnected from all electric energy sources. Control circuit devices, such as push buttons, selector switches, and interlocks, may not be used as the sole means for deenergizing circuits or equip ment. Interlocks for electric equipment may 1910.333(b)(2)(ii)(b) 694.0.24.4 Change 56 SH1NTECH-000JI7 OCCUPATIONAL SAFETY AND HEALTH 1910.333(b)(2)(ii)(b) STANDARDS AND INTERPRETATIONS not be ued as a substitute for lockout and tagging procedures. (e) Stored electric energy which might endanger personnel shall be released. Capacitors shall be discharged and high capacitance elements shall be shortcircuited and grounded, if the stored electric energy might endanger personnel. NOTE: If the capacitors or associated equip ment are handled in meeting this require ment, they shall be treated as energized. (d) Stored non-electrical energy in devices* that could reenergize electric circuit parts shall be blocked or relieved to the extent that the circuit parts could not be acciden tally energized by the device. (iii) Application of locks and tags. (a) A lock and a tag shall be placed on each disconnecting means used to deenergize cir cuits and equipment on which work is to be performed, except as provided-in para graphs (b)(2)(iii)(C) and (b)(2)(iii)(E) of this section. The lock shall be attached so as to prevent persons from operating the discon necting means unless they resort to undue force or the use of tools. (b) Each tag shall contain a statement pro hibiting unauthorized operation of the dis connecting means and removal of the tag. (e) If a lock cannot be applied, or if the employer can demonstrate that tagging pro cedures will provide a level of safety equiv alent to that obtained by the use of a lock, a tag may be used without a lock. (d) A tag used without a lock, as permitted by paragraph (b)(2)(iii)(C) of this section, shall be supplemented by at least one addi tional safety measure that provides a level of safety equivalent to that obtained by the use of a lock. Examples of additional safety measures include the removal of an isolating circuit element, blocking of a controlling switch, or opening of an extra disconnecting device. (e) A lock may be placed without a tag only under the following conditions: (1) Only one circuit or piece of equipment is deenergized, and (2) The lockout period does.not extend beyond the work shift, and (3) Employees exposed to the hazards associated with reenergizing the circuit or equipment are familiar with this procedure. (iv) Verification of deenergized condition. The requirements of this paragraph shall be met before any circuits or equipment can be con sidered and worked as deenergized. (a) A qualified person shall operate the equipment operating controls or otherwise verify that the equipment cannot be restarted. (b) A qualified person shall use test equip ment to test the circuit elements and electrical parts of equipment to which employees will be exposed and shall verily that the circuit elements and equipment parts are deenergized. The test shall also determine if any energized condition exists as a result of inadvertently induced voltage or unrelated voltage backfeed even though specific parts of the circuit have been deen ergized and presumed to be safe. If the cir cuit to be tested is over 600 volts, nominal, the test equipment shall be checked for proper operation immediately before and immediately alter this test. (v) Reenergizing equipment. These require ments shall be met, in the order given, before circuits or equipment are re-energized, even temporarily. (a) A qualified person shall conduct tests and visual inspections, as necessary, to ver ily that all tools, electrical jumpers, shorts, grounds, and other such devices have been removed, so that the circuits and equipment can be safely energized. (b) Employees exposed to the hazards asso ciated with renergizing the circuit or equip ment shall be warned to stay clear of circuits and equipment. (c) Each lock and tag shall be removed by the employee who applied it or under his or Change 56 " 694J 1.24.5 1910.333(b)(2)(v)(c) SHINTECH-000518 1910.333(b)(2)(v)(c) STANDARDS AND INTERPRETATIONS OCCUPATIONAL SAFETY AND HEALTH her direct supervision. However, if this employee is absent from the workplace, then the lock or tag may be removed by a qualified person designated to perform this task provided that: (1) The employer ensures that the em ployee who applied the lock or tag is not available at the workplace, and (2) The employer ensures that the em ployee is aware that the lock or tag has been removed before he or she resumes work at that workplace. > (d) There shall be a visual determination that all employees are clear of the circuits and equipment. (c) Working on or near exposed energized parts. (1) Application. This paragraph applies to work performed on exposed live parts (involving either direct contact or contact by means of tools or materials) or near enough to them for employees to be exposed to any hazard they present. (2) Work on energized equipment. Only qualified persons may work on electric circuit parts or equipment that have not been deenergized under the procedures of paragraph (b) of this section. Such persons shall be capable of work ing safely on energized circuits and shall be familiar with the proper use of special precau tionary techniques, personal protective equip ment, insulating and shielding materials, and insulated tools. (3) Overhead lines. If work is to be performed near overhead lines, the lines shall be deen ergized and grounded, or other protective meas ures shall be provided before work is started. If the lines are to be deenergized, arrange ments shall be made with the person or organi zation that operates or controls the electric circuits involved to deenergize and ground them. If protective measures are provided such as guarding, isolating, or insulating, these pre cautions shall prevent employees from contact ing such lines directly with any part of their body or indirectly through conductive materials, tools, or equipment. NOTE: The work practices used by qualified per sons installing insulating devices on overhead power transmission or distribution lines are not covered by 1910.332 through 1910.335. Under paragraph (c)(2) of this section, unqualified per sons are prohibited from performing this type of work. (i) Unqualified persons. (a) When an unqualified person is working in an elevated position near overhead lines, the location shall be such that the person and the longest conductive object he or she may contact cannot come closer to any unguarded, energized overhead line than the following distances: (1) For voltages to ground 50kV or below--10 ft. (305 cm); (2) For voltages to ground over 50kV--10 ft. (305 cm) plus 4 in. (10 cm) for every lOkV over 50kV. (b) When an unqualified person is working on the ground in the vicinity of overhead lines, the person may not bring any conduc tive object closer to unguarded, energized overhead lines than the distances given in paragraph (c)(3)(i)(A) of this section. NOTE: For voltages normally encountered with overhead power lines, objects which do not have an insulating rating for the voltage involved are considered to be conductive. (ii) Qualified persons. When a qualified person is working in the vicinity of overhead lines, whether in an elevated position or on the ground, the person may not approach or take any conductive object without an approved insulating handle closer to exposed energized parts than shown in Table S-5 unless: (a) The person is insulated from the ener gized part (gloves, with sleeves if neces sary, rated for the voltage involved are considered to be insulation of the person from the energized part on which work is performed), or (b) The energized part is insulated both from all other conductive objects at a dif ferent potential and from the person, or (c) The person is insulated from all conduc tive objects at a potential different from that of the energized part. 1910.333(c)(3)(ii)(c) 694.0.24.6 Change 56 ) SHINTECH-000519 OCCUPATIONAL SAFETY AND HEALTH 1910.333(c)(3)(ii)(r) STANDARDS AND INTERPRETATIONS Table S-5.--approach distances for Qualified Employees Alternating Current Voltage range (phase Minimum approach to phase) distance 300V and less............. Avoid contact. Over 300V, not over 1 ft. 0 in. (30.5 cm). 750V. Over 750V, not over 1 ft. 6 in. (46 cm). 2kV............................. Over 2kV, not over 2 ft. 0 in. (61 cm). 15kV........................... Over 15kV, not over 3 ft. 0 in. (91 cm). ... 37kV. Over 37kV, not over 3 ft. 6 in. (107 cm). 87.5kV. Over 87,5kV, not 4 ft. 0 in. (122 cm). over 121kV. Over 121kV, not over 4 ft. 6 in, (137 cm). 140kV. (iii) Vehicular and mechanical equipment. (a) Any vehicle or mechanical equipment capable of having parts of it structure ele vated near energized overhead lines shall be operated so that a clearance of 10 ft. (305 cm) is maintained. If the voltage is higher than 50kV, the clearance shall be increased 4 in. (10 cm) for every lOkV over that volt age. However, under any of the following conditions, the clearance may be reduced: (1) If the vehicle is in transit with its structure lowered, the clearance may be reduced to 4 ft. (122 cm). If the voltage is higher than 50kV, the clearance shall be increased 4 in. (10 cm) for every 10kV over that voltage. (2) If insulating barriers are installed to prevent contact with the lines, and if the barriers are rated for the voltage of the line being guarded and are not a part of or an attachment to the vehicle or its raised structure, the clearance may be reduced to a distance within the designed working dimensions of the insulating barrier. (3) If the equipment is an aerial lift insu lated for the voltage involved, and if the work is performed by a qualified person, the clearance (between the uninsulated portion of the aerial lift and the power line) may be reduced to the distance given in Table S-5 (b) Eniployees standing on the ground may not contact the vehicle or mechanical equip ment or any of its attachments, unless: (1) The employee is using protective, equipment rated for the voltage; or (2) The equipment is located so that no uninsulated part of its structure (that portion of the structure that provides a conductive path to employees on the ground) can come closer to the line than permitted in paragraph (c)(3)(iii) of this section. (c) If any vehicle or mechanical equipment capable of having parts of its structure elevated near energized overhead lines is intentionally grounded, employees working on the ground near the point of grounding may not stand at the grounding location whenever there is a possibility of overhead line contact. Additional precautions, such as the use of barricades or insulation, shall be taken to protect employees from hazardous ground potentials, depending on earth resistivity and fault currents, which can develop within the first few feet or more outward from the grounding point. (4) Illumination. (i) Employees may not enter spaces containing exposed energized parts, unless illumination is provided that enables the employees to per form the work safely. (ii) Where lack of illumination or an obstruc tion precludes observation of the work to be performed, employees may not perform tasks near exposed energized parts. Employees may not reach blindly into areas which may contain energized parts. (5) Confined or enclosed work spaces. When an employee works in a confined or enclosed space (such as a manhole or vault) that contains exposed energized parts, the employer shall provide, and the employee shall use, protective shields, protective barriers, or insulating mate rials as necessary to avoid inadvertent contact with these parts. Doors, hinged panels, and the like shall be secured to prevent their swinging Change 56 ' 694J 1.24.7 1910.333(cX5) SHINTECH-000520 1910.333(c)(5) STANDARDS AND INTERPRETATIONS OCCUPATIONAL SAFETY AND HEALTH into an employee and causing the employee to contact exposed energized parts. (6) Conductive materials and equipment. Conduc tive materials and equipment that are in contact with any part of an employee's body shall be handled in a manner that will prevent them from contacting exposed energized conductors or cir cuit parts. If an employee must handle long dimensional conductive objects (such as ducts and pipes) in areas with exposed live parts, the employer shall institute work practices (such as the use of insulation, guarding, and material handling techniques) which will minimize the * hazard. (7) Portable ladders. Portable ladders shall have nonconductive siderails if they are used where the employee or the ladder could contact exposed energized parts. (8) Conductive apparel. Conductive articles of jewelry and clothing (such as watch bands, bracelets, rings, key chains, necklaces, metalized aprons, cloth with conductive thread, or metal headgear) may not be worn if they might contact exposed energized parts. However, such articles may be worn if they are rendered non conductive by covering, wrapping, or other insulating means. (9) Housekeeping duties. Where live parts pres ent an electrical contact hazard, employees may not perform housekeeping duties at such close distances to the parts that there is a possibility of contact, unless adequate safeguards (such as insulating equipment or barriers) are provided. Electrically conductive cleaning materials (including conductive solids such as steel wool, metalized cloth, and silicon carbide, as well as conductive liquid solutions) may not be used in proximity to energized parts unless procedures are followed which will prevent electrical contact. (10) Interlocks. Only a qualified person following the requirements of paragraph (c) of this section may defeat an electrical safety interlock, and then only temporarily while he or she is working on the equipment. The interlock system shall be returned to its operable condition when this work is completed. 1910.334--USE OF EQUIPMENT. (a) Portable electric equipment. This paragraph applies to the use of cord- and plug-connected equipment, including flexible cord sets (extension cords). (1) Handling. Portable equipment shall be han dled in a manner which will not cause damage. Flexible electric cords connected to equipment may not be used for raising or lowering the equipment. Flexible cords may not be fastened with staples or otherwise hung in such a fashion as could damage the outer jacket or insulation. (2) Visual inspection. (i) Portable cord- and plug-connected equip ment and flexible cord sets (extension cords) shall be visually inspected before use on any shift for external defects (such as loose parts, deformed and missing pins, or damage to outer jacket or insulation) and for evidence of possible internal damage (such as pinched or crushed outer jacket). Cord- and plug-con nected equipment and flexible cord sets (extension cords) which remain connected once they are put in place and are not exposed to damage need not be visually inspected until they are relocated. (ii) If there is a defect or evidence of damage that might expose an employee to injury, the defective or damaged item shall be removed from service, and no employee may use it until necessary repairs and tests to render the equipment safe have been made. (iii) When an attachment plug is to be con nected to a receptacle (including any on a cord set), the relationship of the plug and recepta cle contacts shall first be checked to ensure that they are of proper mating configurations. (3) Grounding-type equipment. (i) A flexible cord used with grounding-type equipment shall contain an equipment ground ing conductor. (ii) Attachment plugs and receptacles may not be connected or altered in a manner which 1910.334(a)(3)(ii) 694.0.24.8 Change 56 SHINTECH-000521 OCCUPATIONAL SAFETY AND HEALTH 1910.334(a)(3)(ii> STANDARDS AND INTERPRETATIONS would prevent proper continuity of the equip ment grounding conductor at the point where plugs are attached to receptacles. Addi tionally, these devices may not be altered to allow the grounding pole of a plug to be inser ted into slots intended for connection to the current-carrying conductors. (iii) Adapters which interrupt the continuity of the equipment grounding connection may not be used. (4) Conductive work locations. Portable electric equipment and flexible cords used in highly con ductive work locations (such as those inundated with water or other conductive liquids), or in job locations where employees are likely to contact water or conductive liquids, shall be approved for those locations. (5) Connecting attachment plugs. (i) Employees' hands may not be wet when plugging and unplugging flexible cords and cord- and plug-connected equipment, if ener gized equipment is involved. (ii) Energized plug and receptacle connections may be handled only with insulating protec tive equipment if the condition of the connec tion could provide a conducting path to the employee's hand (if, for example, a cord con nector is wet from being immersed in water). (ill) Locking-type connectors shall be properly secured after connection. (b) Electric power and lighting circuits. (1) Routine opening and closing of circuits. Load rated switches, circuit breakers, or other devices specifically designed as disconnecting means shall be used for the opening, reversing, or closing of circuits under load conditions. Cable connectors not of the load-break type, fuses, terminal lugs, and cable splice connections may not be used for such purposes, except in an emergency. (2) Reclosing circuits after protective device opera tion. After a circuit is deenergized by a circuit protective device, the circuit may not be man ually reenergized until it has been determined that the equipment and circuit can be safely energized. The repetitive manual reclosing of circuit breakers or reenergizing circuits through replaced fuses is prohibited. NOTE: When it can be determined from the design of the circuit and the overcurrent devices involved that the automatic operation of a device was caused by an overload rather than a fault condition, no examination of the circuit or con nected equipment is needed before the circuit is reenergized. (3) Overcurrent protection modification. Overcur rent protection of circuits and conductors may not be niodified, even on a temporary basis, beyond that allowed by 1910.304(e), the installation safety requirements for overcurrent protection. (c) Test instruments and equipment. (1) Use. Only qualified persons may perform testing work on electric circuits or equipment. (2) Visual inspection. Test instruments and equipment and all associated test leads, cables, power cords, probes, and connectors shall be visually inspected for external defects and damage before the equipment is used. If there is a defect or evidence of damage that might expose an employee to injury, the defective or damaged item shall be removed from service, and no employee may use it until necessary repairs and tests to render the equipment safe have been made. (3) Rating of equipment. Test instruments and equipment and their accessories shall be rated for the circuits and equipment to which" they will be connected and shall be designed for the environment in which they will be used. (jf) Occasional use of flammable or ignitible mat rials. When flammable materials are present only occasionally, electric equipment capable of igniting them shall not be used, unless measures are taken to prevent hazardous conditions from developing. Such materials include, but are not limited to: flammable gases, vapors, or liquids; combustible dust; and ignitible fibers or flyings. NOTE: Electrical installation requirements for loca tions where flammable materials are present on a regular basis are contained in 1910.307. Change 56 694.0.24.9 1910.334(d) SHINTECH-000522 1910.335 STANDARDS AND INTERPRETATIONS OCCUPATIONAL SAFETY AND HEALTH 1910.335 SAFEGUARDS FOR PERSONNEL PROTECTION (a) Use of protective equipment. (1) Personal protective equipment. (i) Employees working in areas where there are potential electrical hazards shall be provided with, and shall use, electrical protec tive equipment that is appropriate for the spe cific parts of the body to be protected and for the work to be performed. ^ NOTE: Personal protective equipment require ments are contained in subpart I of this part. (ii) Protective equipment shall be maintained in a safe, reliable condition and shall be periodically inspected or tested, as required by 1910.137. (ii) If the insulating capability of protective equipment may be subject to damage during use, the insulating material shall be protected. (For example, an outer covering of leather is sometimes used for the protection of rubber insulating material.) (iv) Employees shall wear nonconductive head protection wherever there is a danger of head injury from electric shock or burns due to con tact with exposed energized parts. (v) Employees shall wear protective equip ment for the eyes or face wherever there is danger of injury to the eyes or face from electric arcs or flashes or from flying objects resulting from electrical explosion. (2) General protective equipment and tools. (i) When working near exposed energized con ductors or circuit parts, each employee shall use insulated tools or handling equipment if the tools or handling equipment might make contact with such conductors or parts. If the insulating capability of insulated tools or handling equipment is subject to damage, the insulating material shall be protected. (a) Fuse handling equipment, insulated for the circuit voltage, shall be used to remove or install fuses when the fuse terminals are energized. (b) Ropes and handlines used near exposed energized parts shall be nonconductive. (ii) Protective shields, protective barriers, or insulating materials shall be used to protect each employee from shock, burns, or other electrically related injuries while that employee is working near exposed energized parts which might be accidentally contacted or where dangerous electric heating or arcing might occur. When normally enclosed live parts are exposed for maintenance or repair, they shall be guarded to protect unqualified persons from contact with the live parts. (b) Alerting techniques. The following alerting tech niques shall be used to warn and protect employees from hazards which could cause injury due to electric shock, bums, or failure of electric equipment parts: (1) Safety signs and tags. Safety signs, safety symbols, or accident prevention tags shall be used where necessary to warn employees about electrical hazards which may endanger them, as required by 1910.145. (2) Barricades. Barricades shall be used in con junction with safety signs where it is necessary to prevent or limit employee access to work areas exposing employees to uninsulated ener gized conductors or circuit parts. Conductive barricades may not be used where they might cause an electrical contact hazard. (3) Attendants. If signs and barricades do not provide sufficient warning and protection from electrical hazards, an attendant shall be sta tioned to warn and protect employees. 'i 1910.335(b)(3) 694.0.24.10 Change 56 ) SHINTECH-000523