Power press brake guarding in job shops

NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.

March 25, 1983

MEMORANDUM FOR: BYRON R. CHADWICK
REGIONAL ADMINISTRATOR

THRU: JOHN B. MILES JR.
DIRECTOR OFFICE OF FIELD COORDINATION

FROM: BRUCE HILLENBRAND
ACTING DIRECTOR, FEDERAL COMPLIANCE AND STATE PROGRAMS

SUBJECT: Point of Operation Guarding on Job Shop Operations Utilizing Power Press Brakes

This is in response to your memorandum of February 14, 1983, reference (b), in which you request clarification of the OSHA requirements pertaining to point of operation guarding on power press brakes as used in job shop establishments.

OSHA's machine safeguarding regulation is one which requires that physical guards or positive acting safeguarding devices protect against each and every point of operation hazard. The OSHA policy regarding the absolute enforcement of this concept is tempered by the many variable circumstances that can occur in the workplace and the existing state-of-the-art regarding available safeguards. Responsible enforcement requires that the unique circumstances associated with the method of manufacture at each establishment be fully evaluated. As a result of manufacturing constraints, less than optimum safeguards may be acceptable if the employer supervises procedures and provides employee training to achieve an effective level of employee safety.

It is necessary to understand that safeguards are defined to mean physical barrier guards or physical devices which will prevent hazardous employee exposure and that safeguarding procedures for the point of operation on power press brakes, both mechanical and hydraulic, is the subject and intent of the ANSI B11.3-1982 consensus standard. Furthermore, OSHA accepts the safeguarding procedures presented in that standard as the current state-of-the-art capability, and numerous contested case actions have been resolved by applying appropriate safeguarding as presented by ANSI B11.3.

A review of the consensus standard B11.3 indicates that the effected industries have not established a safeguarding state-of-the-art for these machines which absolutely precludes employee exposure. The extremely broad versability of press brakes, as well as the various methods of manufacturing and workpiece configurations to which they are adapted, does not give rise to a completely viable general purpose safeguarding concept for all circumstances. Under some conditions absolute safeguarding with present technology appears impracticable. Therefore, in some circumstances alternative safeguarding methods must be applied to provide for employee safety while operating the press brakes.

In job shop or model shop establishments: (1) operators independently accomplish frequent die set-up and adjustments as the tasks require, (2) high volume rates of production forming are not anticipated, (3) the operators are not required to work under stressful conditions, and (4) the piece parts being fabricated are primarily unique, small quantity runs, which are being developed and produced in close coordination with engineering or the customer. Therefore, considerable supervisory (administrative) control may be necessary to enforce adherence to procedural safety practices. Due to the model shop or job shop nature of the operations, each set-up should be independently evaluated so that a procedure, guard, and/or device will assure the safety of the operator(s). The utilization of hazard analysis assessments, effective employee training, and engineering/management control over the manufacturing process should provide acceptable assurance that safe operating procedures are developed and followed.

OSHA Instruction STD 1-12.12, paragraph 4.c, recognizes the need for professional judgement by the compliance staff regarding effective alternative precautions. Compliance personnel must be knowledgeable of the applications for alternative safeguarding procedures in instances where full physical guarding is impractical or impossible.

The OSHA requirement for safeguarding mechanical and hydraulic power press brakes is presented by 29 CFR 1910.212. Since OSHA enforcement actions regarding power press brakes are unique for the circumstances of each manufacturing operation, a fairly comprehensive evaluation must be conducted. The evaluation must ascertain the particular circumstances involved in the production, job shop (limited short run production), or model shop manufacturing process.

Each category of manufacturing in which press brakes are used is indicative of the degree of physical safeguarding which can be reasonably accomplished. The following figure illustrates that the safeguarding concept most suitable, and usually most cost effective, is related to the type of manufacturing.

The state-of-the-art relative to safeguarding of the point of operation as it applies to power press brakes is presented by ANSI B11.3-1982. Section 6. Section 6.1.4(1) (portion attached) of that standard discusses the use of safe distance to provide safeguarding by location where full physical guarding is impractical or impossible, and is an alternative applicable to situations found in model shop and job shop operations where effectively trained operators of the journeyman category operate the equipment. Section 6.1.2 of B11.3 (attached) describes an effectively trained operator.

The use of hand tools to feed a press brake, in order to provide for a safe distance, is another acceptable alternative if supervisory controls are exercised and operators are effectively trained.

Under the guidance of STD 1-12.12, if the conditions for a safe distance are met and the press brake is provided with applicable guarding as specified by ANSI B11.3 (e.g. guarding of the unused portion of the dies and consistent use of material gages/back stops), a de minimus violation pertaining to point of operation guarding may exist. The determination must be resolved between the compliance officer and the Area Director.