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U. S. Department of Labor
Occupational Safety and Health Administration
Directorate of Enforcement Programs
Office of General Industry Enforcement
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Hazards Associated with Hand-Feeding Bar Straightening Machines
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Safety and Health Information Bulletins |
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SHIB 05-20-04 |
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This Safety and Health Information Bulletin is not
a standard or regulation, and it creates no new
legal obligations. The Bulletin is advisory in
nature, informational in content, and is intended to
assist employers in providing a safe and healthful
workplace. The Occupational Safety and Health
Act requires employers to comply with hazard specific
safety and health standards. In addition,
pursuant to Section 5(a)(1), the General Duty
Clause of the Act, employers must provide their
employees with a workplace free from recognized
hazards likely to cause death or serious physical
harm. Employers can be cited for violating the
General Duty Clause if there is a recognized hazard
and they do not take reasonable steps to prevent or
abate the hazard. However, failure to implement
any recommendations in this Safety and Health
Information Bulletin is not, in itself, a violation of
the General Duty Clause. Citations can only be
based on standards, regulations, and the General
Duty Clause. |
Purpose
The purpose of this Safety and Health Information
Bulletin is:
- To inform users of "caught by" and "struck
by" hazards associated with unguarded bar
straightening machines.
- To urge that all employers using bar
straighteners determine if a "caught by" or
"struck by" hazard exists in the operation of
any of their bar straightening machines.
- To provide information that employers can
use to address these hazards.
Background
OSHA’s Toledo, Ohio Area Office investigated a fatal
accident involving a bar straightening machine. The
machine involved was a two-roll-type straightener
manufactured by Medart Inc. (See Figure 1).
The machine straightens round bar stock by passing
the work piece (round bar stock) between (or
through) a straight or concave roll. As the work piece
is fed into the machine, it is drawn in and rotated by
the rollers. The work piece can reach speeds of 1200
RPM or greater depending on the speed setting. The
bar can also move at 50 feet-per-minute into the
machine. The end product is a straight, round bar.
Observation of the referenced Medart machine in
operation revealed that, when fed, the bar immediately spins at high speeds as it engages the rollers. In
addition, as the bar is drawn into the machine, it also
begins a whipping action depending upon the shape of
the bar. The whipping action could cause the bar to
strike anyone who is in close proximity causing serious
injury or death.
In this case, the employer stated that a whipping guard
is installed at feeding point of the machine; however, it
did not prevent injury. Consultation with straightening
machine manufacturers revealed that some operators
do hand feed the straighteners and have had very
serious injuries, such as open fractures of the
extremities, traumatic amputation of digits, and a
disembowelment. The manufacturers strongly recommended that automated feeding equipment be
installed to eliminate hand feeding.
Accident Investigation
The accident investigation revealed that an employee
was hand feeding a round steel bar into a Medart
two-roll straightener. The round bars have rough
surfaces that increase the surface friction making it
more likely to grab loose clothing. When the bar was
engaged by the rollers, it immediately spun at
approximately 1250 RPM and began to move through
the rollers. At this point, the employee’s clothes
became entangled in the rotating bar and forcibly
threw him onto the floor causing fatal injury. An
emergency stop button was near the employee;
however, the employee had insufficient time to actuate
it.
The employer experienced a similar accident one
month prior to the fatality when an employee’s clothes
became entangled in the bar fracturing the employee’s
leg. In this case, the employee was able to actuate an
emergency stop button. An examination of past
accidents revealed that several other employees had
experienced injury from the bar whipping as it was
being fed into the machine. One such accident
resulted in a permanent disability.
Conclusions
OSHA’s machine guarding standard, 29 CFR
1910.212(a)(1), requires employers to provide
machine guarding to protect employees from hazards
created by points of operation, ingoing nip points,
rotating parts, and other machine operations. While
guarding methods must be evaluated with respect to
particular circumstances associated with a specific
piece of machinery, employers who use bar
straightening machines must use effective guarding
methods to protect employees who otherwise would
be exposed to machine hazards. While not an
exhaustive list of permissible options, employers may
consider using one or more of the following methods, as appropriate, to prevent employee exposure hazards
associated with bar straightening machines:
- Installation of a conveyor system to feed stock
automatically into the machine;
- Installation of barrier guards (or enclosures) in
conjunction with automatic feed tables or
semi-automatic feeders;
- Installation of barrier guards (or enclosures) in
conjunction with methods (e.g., pre-feeding
bar de-scaling and smoothing) to reduce the
possibility that the bar will catch employees or
their clothing; and/or
- Use of a hand-feed or gravity-feed system in
conjunction with specially designed feeding
tools that prevent employee exposure.
Reference Standards
29 CFR 1910.212(a)(1)
Figure 1: Bar Straightening Machine |
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