Standard Interpretations - Table of Contents|
| Standard Number:||1928.57|
August 30, 1976
Dr. Gary S. Nelson
Texas Agricultural Extension Service
The Texas A&M University System
Agricultural Engineering Building,
Room 303 College
Station, Texas 77843
Dear Dr. Nelson:
This is in response to your correspondence of June 22, 1976, addressed to Mr. Kilberg regarding compliance with guarding of cotton ginning equipment standards. These standards are found in 29 CFR 1928.57, Guarding of Farm Equipment, Farmstead Equipment, and Cotton Gins. In addition, it confirms your conversation with a member of my staff.
Your questions and the Occupational Safety and Health Administration (OSHA) answers are as follows:
I. Section 1928.57(d)(1)(vii) "Projecting shaft ends not guarded by location shall present a smooth edge and end, shall be guarded by non-rotating caps or safety sleeves, and may not protrude more than one-half the outside diameter of the shaft."
Question #1: Must all three of these elements be present to be in compliance or is it intended to be an "either/or" situation?
Answer #1: It is intended to be an "either/or" situation. See answer to Question #2.
Question #2: Which shafts, not guarded by location, require a cap or safety sleeve?
(a) Shafts which do not present a smooth edge and end projecting greater than one-half the diameter (We assume, of course, that this is YES!)
(b) Shafts which do not present a smooth edge and end projecting less than one-half the diameter of the shaft?
(c) Shafts which do present a smooth edge and end projecting greater than one-half the diameter of the shaft?
(d) Shafts which do present edge and end projecting less than one-half the diameter of the shaft?
Answer #2(a): Yes.
Answer #2(b): Yes.
Answer #2(c): Yes.
Answer #2(d): No.
Question #3: When a shaft is guarded by a non-rotating cap or sleeve:
(a) Must the shaft also present a smooth edge and end (under the cap or sleeve)?
(b) Must the shaft also not protrude more than one-half the diameter of the shaft --
(1) from the shaft bearing (under the sleeve)?
(2) from the safety sleeve?
Answer #3(a): No.
Answer #3(b)(1): No.
Answer #3(b)(2): Nothing should protrude from the safety sleeve, and the shaft and sleeve combination should be kept short enough not to present a tripping or bumping hazard.
II. Section 1928.57(d)(1)(viii) "In power plants and power development rooms where access is limited to authorized personnel, guardrails may be used in place of guards or guarding by location."
Question #4: We assume that Section 1928.57(d)(1)(ii) also applies to power plants and power development rooms utilizing guard railings. Are we correct?
Answer #4: Yes.
Question #5: Should a ginner choose to place a six foot high wall, with an appropriately labelled access door, around a previously "open" power plant, will this now constitute a power development room to which Section 1928.57(d)(1)(viii) would apply?
Answer #5: Yes, as long as the wall prevented employees from inadvertently entering the hazardous area.
Question #6: In the event that the 6 foot high wall discussed in Question #5 also encloses a single functional element (appropriately guarded according to Section 1928.57(d)(2)) due to the infeasibility of its exclusion due to spacing and structural support of the wall, will Section 1928.57(d)(1)(viii) now apply to the enclosed area excluding the single functional element?
Answer #6: Yes.
III. Section 1928.57(d)(2)(v) "All accessible screw conveyor shall be guarded by substantial covers or gratings, or with an inverted horizontally slotted guard of the trough type, which will prevent employees from coming into contact with the screw conveyor."
Question #7: What grating size range will be acceptable to "prevent employees from coming into contact with the screw conveyor? Does Section 1928.57(c)(iii)(A) apply? That is, "the largest dimensions or openings in grating type guards through which materials are required to flow shall be 4 3/4 inches. The area of each opening shall be no larger than 10 square inches. The opening shall be located no closer to the rotating flighting than 2 1/2 inches."
Answer #7: The grating size range acceptable to "prevent employees from coming into contact with the screw conveyor" is the smallest size that will not substantially interfere with the normal functioning of the component. 29 CFR 1928.57(c)(3)(iii)(a) may be used as a guide.
IV. Section 1928.57(a)(9) "A component is guarded by location during operating, maintenance, or servicing when, because of its location, no employee can inadvertently come in contact with the hazard during such operation, maintenance or servicing."
Question #8: We are stating that a "hazard may be guarded by location due to its `location' or `position' in the work environment. For example, any machine hazard located more than 7 feet above the floor, platform or other walking-working surface or any hazard located internal to a machine housing is automatically `guarded by location' and no additional guard or shield is required." Are we correct? Will the "7 foot rule" be applied? Would 6'-11" be close enough to 7' for must it be 7' minimum? Would you give other examples of "guarding by location" for us to use?
Answer #8: You are not entirely correct. The "7 foot rule" is not a part of this specific standard but may be used as a guide. The definition of Guarding by Location is self-explanatory and applied to each employee's exposure. It would be inappropriate to give examples of blanket "guarding by location", since employee work practices may vary.
V. Section 1928.57(d)(1)(iv) "Pulleys of V-belt drives shall be completely enclosed or guarded by location whether or not railings are present. The open end of the pulley guard shall be not less than 4 inches from the periphery of the pulley."
Question #9: Is Section 1928.57(d)(1)(viii) intended to exempt pulleys of V-belt drives in power development rooms from the need for guarding if guarded by a railing?
Answer #9: Yes.
Section 1928.57(d)(1)(v) "Chains and sprockets shall be completely enclosed except that they may be guarded by location if the bearings are packed or if accessible extension lubrication fittings are used."
Question #10: We assume that if accessible extension lubrication fittings are used that this alone does not define the chains and sprockets as "guarded by location." That is, chains and sprockets utilizing accessible extension lubrication fittings must also be completely enclosed or guarded by location (above 7 ft. etc.). Is our assumption correct?
Answer #10: Yes. Your term "guarded by location (above 7 ft. etc.)" may or may not be correct, depending on employee work practices.
If I may be of any further assistance, please feel free to contact me.
John K. Barto, Chief
Division of Occupational Safety Programming
|Standard Interpretations - Table of Contents|