Industrial Safety and Health for Goods and Materials Services - Chapter 15 ppt

Many injuries can result when using hand tools including cuts, lacer ations, eye injuries , overus e ergon omi c related injuries , and at times slips, trips, and falls.. Knives and scis

15 Hand Tools

When we thin k about hand tool s, we norm ally think of hamm ers, screwdri vers, or pliers, but a toothbrus h, a spoon, a pen, scis sors are also hand tool s They are examples of tools that are used to concent rate force and help to carry out a variety

of tasks

For most of us, h and tools are nonpow ered tools and incl ude chise ls, handsaws, wrenches, shovel s, and knives Many injuries can result when using hand tools including cuts, lacer ations, eye injuries , overus e (ergon omi c related injuries ), and

at times slips, trips, and falls In most inst ances these injuries occur due to the incorrect use, use of the wrong tool, or improper maintenan ce of tools Appro xi-mately 8% of all indus trial accide nts a re caused by hand tools The Mine Health and Safety Admini stration found that one out of every four accide nts was due to hand tools Some examp les of hand tool accide nts are as foll ows:

worker

mushroomed heads that might shatter on impact, sending sharp fragments flying (Figur e 15.1)

A variety of hand tools are necessary for day-to-day general maintenance

The employer is responsible for the safe condition of tools and equipment used by employees, even personal tools if being used in the workplace The employer should not issue or permit the use of unsafe hand tools Damages or broken hand tools

‘‘Removed from Service’’ if the tools are not thrown away Employers should assure that employees are trained in the proper use and handling of hand tools and other equipment

Employees, when using saw blades, knives, or other tools, should direct tools away from aisle areas and away from other employees working in close proximity Knives and scissors must be sharp; dull tools can cause more hazards than sharp ones Cracked saw blades must be removed from service

Wrenches must not be used when jaws are sprung to the point that slippage occurs (Figure 15.2) Impact tools such as drift pins, wedges, and chisels must

be kept free from mushroomed heads The wooden handle of tools must not be splintered

Iron or steel hand tools may produce sparks that can be an ignition source

liquids, and other explosive substances are stored or used

Poor condition

FIGURE 15.1 From safe to unsafe chisels (Courtesy of the Department of Energy.)

Teeth on jaws wom Tight fitting wrenches

on bolts

FIGURE 15.2 Wrenches from good to worn (Courtesy of the Department of Energy.)

Appropri ate person al prote ctive equipment (PPE ) such as safety eyew ear and gloves must be worn to protect against hazards that may be encount ered while using

slips wi th or around da ngerous hand tools

15.1 PREVENTING HAND TOOL ACCIDENTS

To prevent hand tool accide nts certa in safe work pract ices should be follow ed Before using han d tool s selec t the correct tool for the job Do not use tool s for jobs they are not inte nded for Provid e workers with training and informat ion about safer work practices and the c orrect methods, p osture, and use of tool s Other work practices that should be addres sed are as follows:

injury, e.g., when using sharp tool s for cutt ing alw ays cut away from the body or hand

directly to other wor kers or use a hand line

as goggle s, safety shoes, and gloves

15.1.1 HAND T OOL K EY P OINTS

Wear approve d PPE such as safety shiel ds, respirato rs, safety toed shoes, high-top shoes, hard hats, bump caps, leat her gloves, leat her aprons , coveral l, and safety eyewear with side shields of industrial quality that conform to the ANSI Z87.1 standard

A variety of gloves exist that have different functional use regarding hand tools

mech-anics gloves with rubber gripping surfaces, mesh gloves that protect from cuts, antivibration or shock absorbing gloves, and the common leather glove that is always

too loose a glove decreases dexterity

Wearing proper clothing varies depending on the type of hand tools that are

protect against burns, wear clothing such as coveralls, high-top shoes, leather aprons, and leather gloves Remove all paper from pockets and wear cuff less pant When working with heavy metals or items wear hard toed shoes with nonskid soles Avoid

burns Do not wear jewelry especially rings when using hand tools since it may result in rings getting caught or contacting electricity Jewelry can get caught on moving parts

Protect the hair, scalp, and head by pulling back long hair in a band or a cap to keep it from getting caught in tools Be extremely careful with long hair when using

a rotating tool When handling carpentry materials wear a hard hat or bump cap to protect the head

gloves and forearm shields When workers are hammering, care must be taken to

Avoid horseplay and loud talking so the mind is not distracted from the task at

serious accidents Be alert and work defensively

As has been said earlier, the greatest accident potential results from misuse and improper maintenance of hand tools By adhering to the following procedures we can mitigate this problem:

used by workers, but workers must also use and maintain tools properly

and other workers working in close proximity

more force and slippage and are more dangerous than sharp tools

workers should use appropriate PPE such as mesh gloves, wrist guards, arm guards, and aprons or belly guards

FIGURE 15.3 Cut resistant Kevlar gloves

. Avoidflammable substances since sparks produced by iron or steel hand tools can be a dangerous ignition source Where these types of hazards exists use spark-resistant tools made of brass, plastic, aluminum, or wood

these jobs Do not use a wrench to drive a nail or use one hammer to strike another

botch a job when used incorrectly Striking a nail with a hammer cheek instead of its face can cause a nailing problem or accident Handling a chisel incorrectly such as pushing a chisel with one hand while the other holds the work in front of the cutting edge can cause severe injury The solution is to clamp in a vise so both hands are free to handle the tool

hand Similarly, a loose or damaged handle can turn a hammer into a deadly flying object

15.1.2 STORINGHANDTOOLS

All tools not in use should be stored where they are not a hazard Sharp edges or pointed tools should have the edge or point guarded at all times when not in use Shovels and rakes should have the sharp or pointed edges toward the ground

15.1.3 OLDHANDTOOLS

Old tools may be unsafe if they lack up-to-date safety features Instead of

hand-me-down or cheap (poorly made) tools from discount stores Although second-hand tools may be cheaper, they can be quite unsafe Any tool with makeshift repairs should be removed from service and discarded so no one is tempted to use it and

be injured

cannot be used again

15.1.4 ERGONOMICS ANDHANDTOOLS

The use of hand tools places a great deal of stress on bones, tendon, ligaments, nerves, and soft tissue Often the use of hand tools can lead to what are called overuse or repetitive injuries Some of the ways to prevent these injuries are by

. Doing gentle exercises during rest breaks

need no more than reasonable force to operate

psychological capabilities

level

15.1.5 ERGONOMICALLYDESIGNEDHANDTOOLS

Hand tools become a problem when workers have to use forceful muscular exertions

while using the tool, having a tool that is too heavy, or wearing gloves that are too large Tools that cause heavy loading of the shoulder while holding the tool, especially when the arm is out from the body, are a problem Wherever there is a possibility of repetitive movement, there is the potential for stress At times contact stress occurs due to tools pressing into the palm at the base of the thumb where blood vessels and nerves pass through the hand If the grip is too wide this can cause a

wrist can also be culprits Efforts should be made to mitigate these types of problems with hand tools

two hands

general guidelines are as follows:

‘‘locking,’’ and strain is sharply increased If the diameter is too small, there

The length of handles is important since poor handle design can be detrimental to the hands Some recommendations are as follows:

. The handle shoul d be long enough so that they do not end in the palm of the

hand especi ally plie rs (Figur e 15.4)

The surfa ces and material that compo se hand les need careful considerat ion All handles shoul d be made from noncondu ctive mat erials Thu s, they shoul d not conduct heat or electrici ty Wood handle is often best for two reason s Wood releases heat to the hand more slowly than p lastic or metal and so it can be of help for a longer period of time before causing an inju ry Wood ga ins h eat more slowly than plastic,

so it is less likely to reach high tem peratures

and legs than noncom press ible concrete, a compressi ble handle is easier on the hand Wood is the best material Compre ssib le rubber or plast ic is ac ceptable Rubber-dipped coatings help make the handle more compressible, less conductive, and cover

Hand tool posture is an important consideration when ergonomically designing tools Bending the tool is superior to bending the wrist Tendon movement while the

position

Another alternative to changing the tool angle is to change the orientation of the work itself Using the appropriate muscle group is less strain and stress

FIGURE 15.4 The end of the screwdriver’s handle does not end in the palm

Hand-closing muscles are stronger than hand-opening muscles Use a spring to open hand tools

15.2 HAND TOOL SPECIFIC SAFETY

15.2.1 ADJUSTABLEWRENCHES

Adjustable wrenches are torsion tools and are used for many purposes They are not intended, however, to take the place of the standard open-ended, box, or socket

15.2.2 AXES

When using an ax, make sure there is a clear circle in which to swing the ax before starting to chop Remove all vines, brush, and shrubbery, especially overhead vines

Ax blades must be protected with a sheath or metal guard whenever possible

of a single-edged ax must be pointed down The cutting edges are designed for cutting wood and equally soft metal Never strike against metals, stone, or concrete Some other important precautions to take with axes are as follows:

use it if the handle is loose or damaged

from the end of the handle and the right hand about three-fourth of the way

up Reverse hands for left-handed individuals

FIGURE 15.5 The pliers’ handles are textured and nonconductive

. Sharp, well-honed axes and hatchets are much safer to use because glancing

is minimized

15.2.3 BOX ANDSOCKETWRENCHES

Box and socket wrenches are used where a heavy pull is necessary and safety is a

and grip all corners as opposed to two corners gripped by an open-ended wrench They will not slip off laterally, and they eliminate the dangers of sprung jaws These types of torsion tools are very versatile This is especially true of socket

must be encouraged where there is danger of injury

Avoid overloading the capacity of a wrench by using a pipe extension (cheater)

on the handle or striking the handle of a wrench with a hammer Hammering on wrenches weakens the metal of a wrench and causes the tool to break Special heavy-duty wrenches are available with handles as long as needed Where possible, use

15.2.4 CARPENTER’S ORCLAWHAMMER

This is a shock tool commonly in use and subject to a great deal of wear The face of

while they are being started into a piece of wood A checkered face head is sometimes used to reduce this hazard Eye protection must be worn when nailing

15.2.5 CHISELS

Choose a chisel only large enough for the job so that the blade is used, rather than the point or corner Never use chisels with dull blades Also, a hammer heavy enough to

do the job should be used The sharper the tool the better it will perform Chisels that are bent, cracked, or chipped shall be discarded, Re-dress cutting edges or structure

to original contour as needed When chipping or shearing with a cold chisel, the tool

shearing plane

Cold chisels should be selected based upon the materials to be cut, the size and shape of the tool, and the depth of the cut to be made The chisel should be made heavy enough so that it will not buckle or spring when struck Always wear safety goggles or a face shield when using a chisel Do not use chisels for prying

15.2.6 CROWBARS

Crowbars are types of prying tools and come in different sizes Use the proper size for the job Never use a makeshift device such as a piece of pipe, since they may slip and cause injury Crowbars must have a point or toe capable of gripping the object

to be moved and a heel to act as a pivot or fulcrum point A block of wood under the heel may prevent slippage and help reduce injuries (Figure 15.6)

15.2.7 CUTTERS

Cutters used on wire, reinforcing rods, or bolts should be sharp enough to cut the material If this is not the case, the jaws may be sprung or spread Cutters require frequent lubrication To keep cutting edges from becoming nicked or chipped, a cutter should not be used as a nail puller or pry bars Cutter jaws have the hardness

edges are spaced 0.003 in apart when closed

15.2.8 FILES

Selection of the right kind offile for the job will prevent injuries and lengthen the life

punch, chisel, or any other types of tools because the hardened steel may break

bind, the tang may puncture the palm of the hand, the wrist, or other body parts Under some conditions, a clamp-on raised offset handle may be useful to give extra clearance for the hands

Files are not to be used on lathe stock turning at high speeds (faster than three

inflict serious injury

FIGURE 15.6 A typical crowbar

15.2.9 HACKSAWS

Hacksaw s should be adjus ted in the fram e to prevent buckling a nd breaking, but should not be tigh t enough to break off the pins that suppor t the blades Inst all blades with teeth pointing forw ard Pressu re shoul d be app lied on the forward stro ke, not the back stro ke Lift the saw slig htly, pulling back lightly to prote ct the teet h If the blades twist or too much press ure is applied, the blades may break a nd cause injury

to the h ands or arm of the user Never continue an old cu t with a dull b lade

15.2.10 HAMMERS

particula r type of head The h andle should be smoo th, without cracks or spli nters,

should be stra ight Once split, the handle s must be repla ced Some other common rules are as follow s:

soft-head ha mmer or one with a plast ic, wood , or raw hide soft-head

against flying chips , nails, or other materials

recom-mended

15.2.11 HATCHETS

Hatchets must not be used for strikin g hard metal surfa ces, since the temp ered head

a hatchet in a crowed area, workers must take special care to prevent injury to themselv es and o thers Usin g a hatche t to d rive nails is prohi bited Refer to Se ction 15.2.2 since the hatche t rules are quit e similar

15.2.12 KNIVES

Knives cause more disabling injuries than any other hand tool The hazards are that the hand may slip from the handle on the blade or that the knife may strike the body

or the free hand Use knives with handle guards if possible Knives are to be kept sharp and in their holders, cabinets, or sheaths when not in use Knife strokes should always be away from the body Use cut resistant gloves when using knives Never carry a sheath knife on the front part of a belt Always carry it over the right or left hip, toward the back This will prevent severing a leg artery or vein in case of a fall

Knives must never be left lying on benches or in other places, where they may cause hand injuries Safe placing and storing of knives are important in knife safety Supervisors must provide ample room to those who work with knives so they are not

in danger of being bumped by other workers Supervisors should be particularly