ERGONOMIC VIBRATION

WHO’S AT RISK?

• ANYONE WHO ABSORBS MACHINE VIBRATION THROUGH THEIR HANDS AND ARMS WHILE WORKING A FAST-MOVING HAND TOOL --

• OR THROUGH THE BUTTOCKS AND THE SOLES OF THE FEET WHILE RIDING IN OR STANDING NEAR VIBRATING, HEAVY MACHINERY--

HOW MANY EXPOSED?

• APPROXIMATELY 1.2 MILLION EXPOSED• 50 -- 60 % OF WORKER POPULATION HAVE

SYMPTOMS

TYPES?

• WHOLE BODY VIBRATION• SEGMENTAL VIBRATION

DEFINITION?

• A CYCLE OF SPECIFIC ACTIVITY BACK-FORTH, UP AND DOWN RESULTING FROM REVERSAL OF ENERGY

• FREQUENCIES OF 100 HZ OR HIGHER ARE ABSORBED BY THE HANDS AND WRISTS

• FREQUENCIES UNDER 100 HZ ARE ABSORBED BY THE UPPER LIMB JOINTS

RESPONSE DEPENDS ON:• FREQUENCY OF VIBRATION• AMPLITUDE OF VIBRATION• TIME HISTORY OF VIBRATION EXPOSURE• DIRECTION OF VIBRATION• POINT OF APPLICATION OF VIBRATION• HOW MUCH VIBRATION IS TRANSMITTED• AFFECT OF CLOTHING AND EQUIPMENT• BODY SIZE (HEIGHT AND WEIGHT)• BODY POSTURE/ BODY TENSION

CONTROL STRATEGIES:

• ENGINEERING AND WORK PRACTICES• ANTI-VIBRATION CLOTHING, EQUIPMENT, AND

TRAINING

• GOALS:– REDUCE THE INTENSITY

– REDUCE THE EXPOSURE DURATION

– IDENTIFY THE EARLY SIGNS AND SYMPTOMS

ENGINEERING CONTROLS:

• REDUCTION AT SOURCE• REDUCTION OF TRANSMISSION• PROCESS MODIFICATION

REDUCTION AT SOURCE• REDUCE SPEED OF TOOL• REDUCE WEIGHT AND POWER NEEDED TO DRIVE

THE TOOL• CHANGE TYPE OF TOOL– E.G. RECIPROCATING ENGINE TO ROTARY OR

ELECTRIC MOTOR• TOOL MAINTENANCE• MOUNT EQUIPMENT ON SPRINGS OR

COMPRESSION PADS• USE MATERIALS THAT GENERATE LESS

VIBRATION

WORK MODIFICATION APPROACHES

• LIMIT NUMBERS OF HOURS • REDUCE NUMBER OF DAYS PER WEEK• ROTATE BETWEEN VIBRATING AND NON-

VIBRATING TOOL TASKS• SCHEDULE MAINTENANCE BREAKS

WORK PRACTICES• LENGTH OF WORK DAY• JOB ROTATION • SELECT LOW VIBRATION TOOLS• DESIGN WORK TASK AND WORKPLACE

ERGONOMICALLY• REDUCE GRIP FORCE APPLIED• REDUCE FORCE APPLIED• RESTRICT USE OF PIECE WORK AND INCENTIVE

PAY• ERGONOMIC WORK POSTURES

ADMINISTRATIVE CONTROLS

• PPE• REDUCE TRANSMISSION OF VIBRATING ENERGY TO THE

HAND• PROTECT AGAINST EXPOSURE TO COLD AND TRAUMA• TRAINING

– SOURCE OF VIBRATION– ADVERSE HEALTH AND SAFETY EFFECTS – EARLY SIGNS AND SYMPTOMS– USE AND AVAILABILITY OF VIBRATION PROTECTIVE CLOTHING– ANTI-VIBRATION DEVICES– VALUE OF GOOD TOOL MAINTENANCE– WORK PRACTICE PROCEDURES

Definitions• Sound: – Composed of Frequency and Intensity

• Frequency or pitch: – Hertz (Hz)

• Intensity or loudness:– Decibels (dBA)

• A doubling of the level of sound is perceived as less than double– Do not trust your ears

Two Types of Hearing Loss

• Conductive• Sensory

Conductive Hearing Loss

• Caused by damage to or a malfunction of the outer and middle ear

• Some causes– excessive ear wax– fluid in the ear– a torn eardrum– Colds

• Usually hearing is restored once the cause is diagnosed and treated

• Foam earplugs• Earmuffs• Noise Reduction

Rating ( NRR )

– Plugs + Muffs• Take the higher NRR

and add 5 dB to it

Types of Hearing Protection Devices

• It doesn’t matter how many resources we have• If we don’t know how to use them, they will never be enough• We may have too many lighting fixtures but if they are not

properly positioned we will still have an issue

IMPROPER UTILIZATION OF RESOURCES

HIGH BEAM LIGHTS result in glare This will happen in over illumination .