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• Standard Number: 1910.147; 1910.147(a)(2)(ii); 1910.212


January 18, 2006

Mr. Dennis O'Hagan
Columbia University
B-230 East Campus
Mail Code 3405
410 West 118th Street
New York, NY 10027

Dear Mr. O'Hagan:

Thank you for your January 21, 2005 letter to the Occupational Safety and Health Administration's (OSHA's) Directorate of Enforcement Programs. This letter constitutes OSHA's interpretation only of the requirements discussed and may not be applicable to any questions not delineated within your original correspondence. You had specific questions regarding the use of interlocks on a trash compactor. We apologize for the delay in responding to your letter.

We have restated your questions below.

Question #1: Is an interlock required on the side door of a trash compactor, if the side access door is located 55 inches from ground level, and the door is closed and latched while the compactor is cycling?

Response: If an employee may be exposed to machine hazards while the machine operates, the hazardous areas of the machine must be guarded. The Occupational Safety and Health Review Commission has found employee exposure where it is reasonably predictable, either by operational necessity or otherwise (including inadvertence), that employees have been, are, or will be in the machine's zone of danger. While it is not possible to conclusively determine the answer to your question without observing the trash compactor and considering the manner in which it is situated and used, it is likely that employees would be exposed to moving parts associated with the trash compactor during the course of their employment. As such, OSHA's machine guarding standard (29 CFR §1910.212) likely would require guarding to prevent employee exposure to the hazards.

While properly designed, constructed, and maintained interlocks generally provide effective machine guarding, §1910.212 does not require the use of interlocks or any other specific guarding methods. The standard describes several acceptable methods for guarding machine hazards, but the standard is performance-oriented, and an employer can comply with the standard by using any method(s) of guarding that provides effective employee protection against the hazard. In the scenario that you described, access to the trash compactor's point-of-operation is covered by a latched, solid door. If the door effectively prevents employee access to the point-of-operation or other machine hazards, the door would be considered effective guarding. However, since barrier guards must be affixed such that they cannot be easily defeated, simply latching the door in a closed position would not be sufficient. Thus, the door would need to be secured such that it could not be easily circumvented (e.g., by use of means such as fasteners not readily removable by the operator, a lock, etc.) or, if access is desired using only a latch, an interlock or other guarding method must be used to prevent employee exposure to the trash compactor's point-of-operation.

Please be aware that, should employees be exposed to hazardous energy during servicing or maintenance activities associated with the trash compactor, which require the side access door to be opened, employees can access the danger zone only pursuant to a lockout/tagout program that is compliant with §1910.147. Pursuant to that standard, certain "minor servicing activities" may be performed using alternative guarding measures, including barrier guards with properly designed interlocks, which provide effective employee protection. See 29 CFR §1910.147(a)(2)(ii) (Note).

Question #2: Does federal OSHA have an interpretation of ANSI Z245.2?

Response: OSHA does not issue citations for violations of ANSI standards that have not been adopted as (or incorporated into) OSHA standards, but ANSI or other industry standards are sometimes referred to in citations and used as evidence of a recognized hazard or a feasible means of abatement. Employers should contact the appropriate ANSI committee for official interpretations of ANSI standards.

While not interpreting ANSI Z245.2 (2004), American National Standard for Equipment Technology and Operations for Wastes and Recyclable Materials — Stationary Compactors — Safety Requirements for Installation, Maintenance and Operation, we note that this ANSI standard requires that "[a]ccess door(s) of loading chambers [on trash compactors] shall have an interlock system that prevents cycling motion while the access door(s) is open." Section 5.8.1. We are aware of no provision in ANSI Z245.2 (2004) that would permit a side access door to be accessible to employees without the incorporation of an interlock system merely because the side access door was 55 inches above ground level. Rather, the ANSI standard provides that the access door must be interlocked unless "[s]ustained-manual-pressure controls [are] located in such a way that the operator cannot reach the point-of-operation and [are] within an area fully visible to the operator of the complete point-of-operation area when the guard is not used." Section 5.9.1(c). Your letter provides no indication that the compactor at your facility has such controls. We also recognize that the ANSI standard permits an opening into a compactor if the length of a fixed guard (or loading hopper) in conjunction with the height of the opening from the ground exceeds 84 inches, so as to "prevent any persons from contacting moving parts at the point-of-operation." Section 5.9.1(a). However, this recognized guarding method is not applicable to the present situation, in which the compactor has a side access door that is only 55 inches from the ground and lacks a fixed guard or loading hopper designed to prevent access to the compactor's moving parts.

Question #3: Does federal OSHA recognize a state Occupational Safety and Health Division interpretation letter as proper guidance and interpretation for regions outside of that state?

Response: Federal OSHA enforces federal standards in states not covered by state OSHA plans. When a state official interprets a state standard promulgated pursuant to a state occupational safety and health statute, the interpretation definitively addresses only the application of the relevant state standard.
1 Employers subject to federal OSHA authority should seek an interpretation from federal OSHA regarding the application of federal OSHA standards promulgated pursuant to the Occupational Safety and Health Act.

Thank you for your interest in occupational safety and health. We hope you find this information helpful. OSHA requirements are set by statute, standards, and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at
http://www.osha.gov. If you have any further questions, please feel free to contact the Office of General Industry Enforcement at (202) 693-1850.

Sincerely,



Richard E. Fairfax, Director
Directorate of Enforcement Programs


1 We note, however, that the opinion offered in the Oregon Occupational Safety and Health Division (OSHD) letter that you referenced (July 8, 1997 from Marilyn K. Schuster to Dale Anderson) is consistent with the provisions of the ANSI Z245.2 standard, which are discussed in response to your second question (above). The Oregon OSHD letter addresses a loading chute that is 42 inches above the floor and is further guarded by a 4-foot, fixed loading hopper that extends out from the compactor at that height. Thus, this would meet the 84-inch total protective distance that is contemplated in Section 5.9.1 of the ANSI standard.
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