Accident Prevention Manual - PowerPoint PPT Presentation


PPT – Accident Prevention Manual PowerPoint presentation | free to download - id: 80cfc5-YmQxN


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation

Accident Prevention Manual


Title: Chapter 21 Woodworking Machinery Author: Grant Weller Last modified by: Deborah Meyer Created Date: 3/11/2013 2:51:22 PM Document presentation format – PowerPoint PPT presentation

Number of Views:78
Avg rating:3.0/5.0
Slides: 63
Provided by: Grant199
Learn more at:


Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Accident Prevention Manual

  • Accident Prevention Manual
  • for Business Industry
  • Engineering Technology
  • 13th edition
  • National Safety Council

Compiled by Dr. S.D. Allen Iske, Associate
Professor University of Central Missouri

General Safety Principles
  • Use equipment that meets OSHA, ANSI, and NFPA
    National Electrical Code standards.
  • Specify needs during purchasing.
  • Maintain all machines so that while they are
    running at full or idle speed and with the
    largest cutting tool attached, they are free of
    excessive noise and vibration.
  • Level all machines, including portable or mobile
  • Secure machines to the floor or other
    foundations, when possible, to eliminate

General Safety Principles (Cont.)
  • Secure small units to benches or stands.
  • Make sure the machine is constructed so that
    tools that are too large cannot be mounted.
  • Ensure that all arbors and mandrels have firm and
    secure bearings and are free from slip or play.
  • Regularly check the adjustment of all safety
  • Those involving electrical circuits should be
    actuated to make sure they operate properly.
  • Operators should lock out machines before
    cleaning, adjusting, or maintaining them.

General Safety Principles (Cont.)
  • Keep loose clothing, long hair, jewelry, and
    gloves away from rotating parts of machinery.
  • especially from nips points and the point of
  • After the equipment has been completely stopped,
    clean work surfaces with a brush, not with the
    hand or a compressed air nozzle.
  • If possible, make adjustments only while the
    machine is not running.

General Safety Principles (Cont.)
  • Electrical equipment
  • All metal framework on electrically driven
    machines should be grounded, including the motor.
  • Comply with NFPA 70, National Electric Code.
  • NFPA 70 includes the following provisions
  • The machine shall have a cutoff devices
    (EMERGENCY STOP) within reach of the operator in
    the normal operating position.
  • Electrically driven equipment shall be controlled
    with a magnetic switch or other device that
    prevents automatic restart after power failure.

General Safety Principles (Cont.)
  • Example of devices stopping restart

General Safety Principles (Cont.)
  • Electrical equipment (cont.)
  • Position clearly marked power and operating
    controls within reach of the operator and away
    from hazards.
  • Protect operating controls against unexpected or
    accidental activation.
  • Provide a positive means (lockout) for rendering
    the controls inoperative in each machine operated
    by an electric motor.
  • If the machine does not have a power disconnect
    to lock it in the OFF position, unplug the cord
    and place a small padlock through the holes in
    the plug.
  • Install an electric motor break on machines that
    have excessive coasting time.

General Safety Principles (Cont.)
General Safety Principles (Cont.)
  • Guards
  • Enclose or guard all belts, shafts, gears, and
    other moving parts so no hazard is present for
    the operator.
  • Because most woodworking operations involve
    cutting, it is necessary, although often
    difficult, to provide guards at the point of

General Safety Principles (Cont.)
  • Guards (cont.)
  • Point-of-Operation Guards must
  • be moveable to accommodate the wood.
  • balanced so as not to impede the operations.
  • strong enough to provide protection to the
  • Whenever possible, completely cover blades and
    cutting edges at the point of operation.

General Safety Principles (Cont.)
  • Work areas
  • Provide ample work space around each machine.
  • See Table 21A for recommendations.
  • Make adjustments if the worker is taller or
    shorter than average.
  • Perform routine floor maintenance in the work
    area to prevent splintering and protruding nails.
  • Install slip-resistant flooring and mark
    aisleways with paint, railings, or other

General Safety Principles (Cont.)
General Safety Principles (Cont.)
  • Work areas (cont.)
  • Maintain good housekeeping to prevent dust and
    chip accumulation.
  • A clean operation makes work easier and helps
    prevent fire and dust explosions.
  • Adequately light the work area and adjacent stock
  • General illumination of 80 to 100 fc (861 to 1076
    lux) will pay dividends in both accident
    prevention and efficiency.

General Safety Principles (Cont.)
  • Materials handling
  • Facility layout should encourage an even flow of
    materials and keep backtracking and crisscrossing
    to a minimum.
  • Operators shouldnt have to stand in or near
  • Arrange the machines so that the materials
    handled by the operator require minimum movement
    and changes of heights.
  • This applies to both incoming supply and outgoing

General Safety Principles (Cont.)
  • Inspection
  • Make safety checks by putting machines through
    trial runs before beginning a job and after each
    new setup.
  • The operator should inspect the machine at each
    new setup and at the start of each shift.
  • The inspection process should follow the
    manufacturers recommendations and requirements
    and flow patterns of the workplace.

General Safety Principles (Cont.)
  • Hearing protection and conservation
  • Most woodworking machinery creates high noise
    levels requiring that employers establish and
    maintain hearing conservation programs.
  • Management should hire a qualified person or IH
    person to take sound-level measurements.
  • If sound level readings (dBA, slow response)
    exceed 85 dBA over an 8-hour period, that worker
    must be included in the hearing conservation

General Safety Principles (Cont.)
  • Fine dust
  • When woodworking processes create fine dusts, the
    EHS professional should have the amount sampled.
  • Observe established threshold limit values (TLVs)
    and maximum permitted exposure (MPE) levels.
  • Fine dust can be a health, fire, or explosion
  • For workers protection, respirators that reduce
    inhalation of various types of nuisance dust are

General Safety Principles (Cont.)
  • Personal protective equipment
  • All individuals in the work area should wear eye
  • ANSI Z87.1 compliant goggles are recommended.
  • Some operations may require operators to wear
    face shields with safety glasses.
  • Workers should wear hair nets or caps to protect
    long hair.
  • Workers can protect their hands with gloves when
    handling wood but should avoid gloves near moving
  • Where there is the danger of kickback, workers
    should wear proper abdominal guards.

General Safety Principles (Cont.)
  • Standards and codes
  • There are a number of OSHA standards, such as 29
    CFR 1910.23, Woodworking Machine Requirements,
    that state required safety features for
    woodworking machines.
  • Some states and other jurisdiction have codes
    that specify requirements.
  • The National Safety Council library has available
    a number of occupational safety and health data
    sheets on woodworking machines.

  • All saws pose potential hazards for operators.
    EHS professionals can minimize these hazards by
  • providing training for operators.
  • ensuring that all machinery is properly guarded.
  • making sure that all ANSI, NFPA, and government
    regulations are followed.

Saws (Cont.)
  • Circular saws
  • Blade cuts or abrasions and kickbacks are among
    the most frequent incidents involving circular
  • These can be minimized by proper guarding and
    training and by enforcing safe work procedures.
  • Circular saws are designed to permit a wide range
    of cutting tasks.
  • The problem with saws, as with most multiple-use
    equipment, is the difficulty in designing one
    guard that offers maximum protection for all
    types of tasks.

Saws (Cont.)
  • Circular Saws
  • 21-5 and 21-6

Saws (Cont.)
  • Circular sawskickback and ripping
  • A kickback occurs during a ripping operation when
    part or all of the work piece is violently thrown
    back to the operator
  • To avoid kickbacks operators should do the
  • maintain the rip fence parallel to the blade.
  • keep the blade sharp and replace anti-kickback
    pawls when they become dull.
  • keep blades guards, spreaders, and anti-kickback
    pawls in place and operating properly.

Saws (Cont.)
  • Circular Sawskickbacks and ripping (cont.)
  • Prevention methods
  • Cut only material that is seasoned, dry, and flat
    and that has a straight edge to guide it along
    the rip fence.
  • Release work only when it has been pushed
    completely past the blade.
  • Use a push stick for ripping widths of 2 to 6 in.
    and auxiliary fence and push block for ripping
    widths narrower than 2 in.
  • Allow the cutoff piece to be unconfined when
    ripping or cross cutting.
  • Apply the feed force to the section of the work

Saws (Cont.)
  • Ripping
  • procedure

Saws (Cont.)
  • Circular sawsguards
  • Supervisors and operators should check that the
    spreader is rigidly mounted and fully elevated at
    least 2 in.
  • Guard a circular table saw, used for cutting,
    with a hood that completely covers the blade
    projecting above the table.
  • Operators should let the guard ride the stock
    being cut, adjusting to the thickness of the

Saws (Cont.)
Saws (Cont.)
Saws (Cont.)
  • Circular sawsrabbeting and dadoing
  • When rabbeting and dadoing, it is impossible to
    use a spreader and often impractical to use the
    standard hood guard.
  • These operations can be guarded by a jig that
    slides in the groves of the transverse guide.
  • The hazards of these jobs justify special
    guarding, especially when work is being done on
    small stock.
  • Operators can use feather boards to hold the work
    to the table and against the fence as it is fed
    past the dado head.

Saws (Cont.)
Saws (Cont.)
  • Circular Sawsproper operating methods
  • Only authorized persons should operate circular
  • A saw in good condition and running at the
    correct speed should cut easily.
  • If a saw does not cut as fast as it should, or if
    it doesnt saw a clean, straight line, the saw
    blade or running speed may be improperly set.
  • Never use a blade larger than what is allowed for
    the mandrels speed.
  • Use the right saw for the right job.
  • Take into consideration blade height.
  • Operators should stop a circular table saw before
    leaving it.

Saws (Cont.)
Saws (Cont.)
  • Circular Sawsselection and maintenance
  • The characteristics and conditions of
    circular-saw blades are important safety factors
    for the operators who use them.
  • When operators alter the original design of a saw
    they seriously affect the saws efficiency and
  • There are numerous conditions which may cause
    unsafe, difficult, or unsatisfactory operation
  • blade out of round
  • blade not straight
  • improper or uneven set
  • dull blades
  • improper bushings
  • cracked blades

Saws (Cont.)
Saws (Cont.)
Saws (Cont.)
Saws (Cont.)
  • Overhead swing saws and straight-line pull cutoff
  • Can cause hand and body injuries in several ways
  • while the blade coasts or idles
  • when operators remove a sawed section or scrap
  • when operators measure boards or place them in
    position for the cut
  • if saw bounces forward from retracted position
  • pulling the saw against their hands in the
    cutting path

Saws (Cont.)
  • Overhead swing saws and straight-line pull cutoff
  • Guarding
  • Must have a guard hood that extends 2 in. in
    front of the blade.
  • Provide a counterweight to return the saw when
    not cutting without rebounding.
  • Install a limit chain or magnetic latches
  • Easily accessible START/STOP buttons

Saws (Cont.)
  • Overhead swing saws and straight-line pull cutoff
  • If the saw is pulled by a handle, the handle
    should be attached to either the right or the
    left of the saw rather than in line with it.
  • The operator should stand to the handle side and
    pull the saw with the hand near it.
  • At the completion of each cut, the operator
    should put the saw back to the idling position
    and make sure all bounce back has stopped before
    putting his/her hand on the table.

Saws (Cont.)
  • Radial saws
  • When cross cutting, radial saws cut downward and
    pull the wood away from the operator and against
    a fence.
  • Always guard the upper half of the saw, including
    the arbor end.
  • The lower guard should auto-adjust to the stock
    thickness and remain in contact with the stock
    being cut for the full working range.
  • The saw table should be large enough to cover
    the blade in any position (miter, bevel, or
  • Radial saw injuries are typically caused by cuts
    to the arms and hands from the blade, flying
    wood chips, and handling materials.

Saws (Cont.)
  • Radial sawsripping
  • Before ripping position the nose of the guard,
    spreader and anti-kickback devices.
  • When ripping, rotate the radial saws head 90o so
    the blade is parallel to the fence and is clamped
    in position.
  • Feed the stock against the direction of rotation
    of the revolving blade.
  • CAUTION Operators should always follow the
    proper direction of blade rotation.
  • Feeding from the wrong side tends to grab the
    material away from the operator and throw it
    toward the end of the guard.

Saws (Cont.)
Saws (Cont.)
Saws (Cont.)
  • In-ripping gt
  • Out-ripping gt

Saws (Cont.)
  • Radial sawsripping (cont.)
  • Two possibilities of severe injury arise from
    feeding from the wrong side.
  • Hands can be drawn into the saw.
  • Flying stock
  • Operators should exercise special care when
    ripping material with thin, lightweight, hard, or
    slippery surfaces because of the reduced
    efficiency of anti-kickback devices.
  • When ripping, the operator should wear an
    anti-kickback apron.

Saws (Cont.)
  • Radial sawscrosscutting
  • Radial saws used for crosscutting are pulled
    across the cutting area by means of a handle
    located to one side of the blade.
  • Operators should stand on the handles side and
    not be in line with the blade.
  • Never remove short pieces from the table until
    the saw has been returned.
  • Workers should develop the habit of holding their
    arms straight from their shoulder to their waist
    because of the blades direction of rotation and
    the feed direction.

Saws (Cont.)
  • Power-feed ripsaws
  • The working end of the saw should have 3 ft of
  • Operators should adjust feed rolls to the
    thickness of the stock being ripped.
  • Insufficient pressure on the stock can contribute
    to kickbacks.

Saws (Cont.)
  • Band saws
  • Injuries from band saws are less frequent and
    severe than other saws.
  • Push stick to control the work piece when its
    close to the blade.
  • Ensure the working area is well lit.
  • Install adjustable guard when possible.
  • Install a brake for band saws that run for a long
    time after the power is shut off.
  • When working small pieces, use a special jig or

Saws (Cont.)
Woodworking Equipment
  • All woodworking equipment poses safety hazards
    for those operating it or working around or near
    the equipment.
  • Workers must be trained in safe work practices
    and in emergency first aid and other procedures
    to prevent or minimize injuries.
  • Common equipment includes
  • jointers-planers
  • shapers
  • power-feed planers
  • sanders
  • lathes and shapers

Woodworking Equipment (Cont.)
  • Joint-planers
  • Second only to circular saws, they are the most
    dangerous woodworking machines.
  • Most injuries are caused when the hands and
    fingers of operators come in contact with these
    machines knives when working with short lengths
    of stock.
  • The openings between the table and the head
    should be just large enough to clear the knife.
  • Use hold-down push blocks whenever the operator
    joints wood narrower than 3 in.
  • Operators should never place their hands over the
    front or back edges.

Woodworking Equipment (Cont.)
Woodworking Equipment (Cont.)
Woodworking Equipment (Cont.)
Woodworking Equipment (Cont.)
  • Shapers
  • The greatest number of injury incidents occurs
    when shaping narrow stock.
  • Use hold-down push block or jigs in these
  • Always feed against the direction of the rotation
  • Eliminate the danger from broken or thrown knives
    by using solid cutters that fit over the spindle.
  • Cutters are always safer than knives.
  • Use applicable guards when possible.
  • Adjust the cutting-head guard for minimum head

Woodworking Equipment (Cont.)
Woodworking Equipment (Cont.)
  • Power-feed planers
  • Operators can reduce planer vibration by
    anchoring the planer on a solid foundation and by
    insulating it from the foundation.
  • Due to the noise they generate, power-feed
    planers should be used in a separate room or
    soundproof enclosure.
  • Completely enclose cutter heads in solid metal
  • Never adjust feed rolls, cutter heads, and
    cylinders during operation. Use proper lockout
  • Ensure that operators and other work stations are
    not positioned on the backside of power-feed
    planer operations.
  • The danger of kickbacks cannot be entirely
    overcome by mechanical means.

Woodworking Equipment (Cont.)
  • Sanders
  • Enclose drum, disk, or belt-sanding operations
    with dust exhaust hoods.
  • Use applicable guard feed rolls at each running
    nip point.
  • All hand-feed sanders should have a work rest and
    (1) be properly adjusted to provide minimum
    clearance between the belt and rest and (2) to
    secure support for the work.
  • Operators should inspect abrasive belts before
    using them and replace those found to be torn,
    frayed, or excessively worn.

Woodworking Equipment (Cont.)
  • Lathes and shapers
  • Supervisors or operators should ensure that the
    rotating heads of lathes, whether running or not,
    are covered as completely as possible by hoods or
  • Use hinge hoods that can be thrown back when
    adjustments are needed.
  • Management should select and train lathe
    operators with care.
  • Operators must give constant attention to stock
    being turned in order to discard any material
    likely to break.
  • Operators must wear proper PPE safety goggles
    and face shield.

  • All electrically driven machines should be
    adequately grounded, have a cutoff switch, and
    have some means of rendering controls
  • Employees using woodworking machines should read
    the operators manual prior to working with new
  • Employees must follow good housekeeping
    procedures around their work area.
  • Management should guard against hearing loss,
    airborne dusts and contamination, explosion, and
    fire hazards.
  • Management can minimize hazards posed by saws by
    training operators, ensuring all machines are
    guarded, and making sure operators follow all
    safety procedures.