hand arm and whole body vibrations exposure- directive...

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Hand Arm and Whole Body vibrations

exposure- directive and standard

OSHNET SCHOOL

Izmir, 2011 May 13th

Riccardo Fusi

Occupational Health & Safety NETworking in EASTern Europe

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The title lays down minimum requirements for the

protection of health and safety of workers who are exposed

or may be exposed to risks from mechanical vibration

Legislative Decree 2008, April 9th

n. 81

TITLE VIII PHYSICAL AGENTS

HEADING III - mechanical vibration

Based on Directive 2002/44/EC

on the minimum health and safety requirements regarding the exposure of

workers to the risks arising from physical agents (vibration)

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It introduces some definitions:

Hand-arm vibration: the mechanical vibration that, when

transmitted to the human hand-arm system, entails risks

to the health and safety of workers, in particular vascular,

bone or joint, neurological or muscular disorders.

Whole-body vibration: the mechanical vibration that,

when transmitted to the whole body, entails risks to the

health and safety of workers, in particular lower-back

morbidity and trauma of the spine.

Legislative Decree 2008, April 9th n. 81

TITLE VIII - HEADING III: mechanical vibration

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A. Hand-arm vibration. The assessment of the level of exposure to

hand-arm vibration is based on the calculation of the daily exposure

value normalised to an eight-hour reference period A(8), expressed as

the square root of the sum of the squares (rms) (total value) of the

frequency-weighted acceleration values, determined on the

orthogonal axes (ahwx, ahwy, ahwz) as defined in ISO 5349-

1(2001).

A(8)=( iahvi2Ti/480)0.5 ISO 5349-1/2001



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mechanical vibration: HAV

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B Whole body vibration. The assessment of the level of exposure to

vibration is based on the calculation of daily exposure A(8) expressed

as equivalent continuous acceleration over an eight-hour period,

calculated as the highest value of the frequency-weighted

accelerations, determined on three orthogonal axes (1,4awx,

1,4awy, awz for a seated or standing worker), in accordance with

ISO 2631-1(1997).

A(8)=( iaw,2Ti/480)0.5 (ISO 2631-1 B1)



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mechanical vibration: WBV

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Frequency is the number of times per second the vibrating body

moves back and forth. It is expressed as a value in cycles per

second (hertz)

mechanical vibration

the risk of damage is not equal at all frequencies, so a frequency-weighting is used to represent the damage from the different frequencies.

for HAV, the important frequencies are in the range from about 8

Hz to 1000 Hz and only one frequency-weighting curve is used for

all three axes;

for WBV, the important frequencies are in the range from about 0,5

Hz to 80 Hz and two frequency-weighting curve are used for three

axes (one for lateral axes and one for vertical)

for WBV an additional multiplying factor must be applied (1.4. for

the lateral, 1.0 for the vertical)

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Exposure limit values and action values for hand-arm vibration

The daily exposure limit value

A(8)= 5 m/s2

The daily exposure action value

A(8)= 2,5 m/s2



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Exposure limit values and action values for whole-body vibration

The daily exposure limit value (1)

A(8)= 1,0 m/s2

The daily exposure action value

A(8)= 0,5 m/s2



(1) The value for daily exposure fixed by EU Directive 2002/44 was 1,15 m/s2

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the level, type and duration of exposure;

the exposure limit values and the exposure action values;

any effects concerning the health and safety of workers at particularly sensitive risk (for example pregnant women and children);

any indirect effects on worker safety resulting from interactions between mechanical vibration and the workplace or other work equipment;

the employer shall assess and, if necessary, measure the levels of mechanical vibration to which

workers are exposed, considering:



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information provided by the manufacturers of work equipment;

the existence of replacement equipment designed to reduce the levels of exposure to mechanical vibration;

specific working conditions such as low temperatures, wet places, high humidity);

biomechanical overload of the upper limbs and spine.

the employer shall assess and, if necessary, measure the levels of mechanical vibration to which

workers are exposed, considering:



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assessment can be made using measures already carriedout by authorized agencies and reported on specificdatabases or using data provided by the manufacturersof the equipment;

in order to use these data it is necessary that theequipment is in good repair and operating conditionscomparable to those of the ones measured;

in any case, the data can not be used directly, but it isnecessary to use correction factors (multiplier coefficient);

if manufacturers declare emission values less than 2.5m/s²,

a value of 2.5m/s² should be used and multiplied by the

appropriate factor.

it is necessary to verify the presence of factors that mayincrease the risk.

Assessment can be made without measurements



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being exposed to vibration for long periods without changing position;

being exposed to vibration sitting in a stretched or twisted posture (e.g. looking over our shoulder);

being exposed to vibration and then doing work involving manually lifting heavy loads

environmental factors, such as temperature, working conditions, humidity may increase the risk

Other factors can separately cause back pain. If a worker

is exposed to one or more of these factors while being

exposed to vibration, the risk will be increased.

Factors increasing the risks

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Measurements

the apparatus used must beadapted to the particularcharacteristics of the vibration tobe measured and to the ambientfactors;

HAV: compliant to EN ISO 5349-1:2004 and EN ISO 5349-2: 2004

WBV: compliant to ISO 2631-1:2008

biennial calibration at EA laboratories (European Accreditation Centre);

instrumentation calibrated before and after the measurements with a calibrator compliant to EN ISO 8041:2005

To make the measures is necessary to use an

instrument with the following features:

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Measurements

the vibration on handheld and hand-guided machines can be very high and can easily overload unsuitable transducers.

fixing transducers to the machine handles requires mounting systems that are rigid, lightweight and compact.

transducers cannot create vibration

It is important that instruments (accelerometers) are

carefully selected:

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Measurements

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Measurements

the methods used may include sampling, which must be

representative of the personal exposure of a worker;

measurements should be made to produce vibration values

representative of the average vibration for a tool or process

throughout the operator’s working period.

it is really important to recreate the usual working

conditions

in the case of devices which need to be held with both hands,

measurements must be made on each hand. The

exposure is determined by reference to the higher value of

the two; information for the other hand shall also be given;

When measurement is employed:

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Hand-arm vibration measurement

equipment 1 notes

X axis frequency-weighted ahwx

(m/s2) 3,72 [m/s2]

Y axisfrequency-weighted ahwy

(m/s2) 3,61 [m/s2]

Z axisfrequency-weighted ahwz

(m/s2) 3,54 [m/s2]

ISO 5349-1/2001 (1) vectorial sum ahv 6,28 [m/s2]

average time of use 2 minute/dayequipment 2 notes

X axisfrequency-weighted ahwx

(m/s2) 5,10 [m/s2]


(m/s2) 4,72 [m/s2]


(m/s2) 3,32 [m/s2]


average time of use 2 minute/dayequipment 3 notes

X axisfrequency-weighted ahwx

(m/s2) 3,24 [m/s2]


(m/s2) 1,31 [m/s2]


(m/s2) 0,89 [m/s2]


average time of use 10 minute/dayA 8 = ( 6.28 2 x 2 + 7.70 2 x 2 + 3.61 2 x 10) 0.5 = 0.83 m/s²

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A 8 = ( 0.35 2 x 90 + 0.48 2 x 150 + 0.77 2 x 120) 0.5 = 0.49 m/s²

machinery 1 note

X axis frequency-weighted awd (m/s2) 0,25 [m/s2]

Y axis frequency-weighted awd (m/s2) 0,22 [m/s2]

Z axis frequency-weighted awk (m/s2) 0,28 [m/s2]

maximum aw 0,35 [m/s2]

average time of use 90,00 minute/day

machinery 2 note






machinery 3 note






Whole body vibration measurement

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Calculation of personal exposure: procedure

measurement of the level of vibration emitted by

each equipment used by workers;

measured values must be processed to obtain

personal exposure levels of all employees of the

company;

results are reported in the form of personal cards.

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Calculation of personal exposure: procedure

personal cards contain used

equipment, their usage time

and the measured vibration

level;

in case of different working

days, multiple cards should

be developed, one for each

different day.

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vibration magnitude data is based on measurements when the machine is working: count only the time that the worker is exposed to vibration, don’t consider the periods without vibration exposure (ex. waiting times to load a truck, handing a tool without using it)

observe work during a part of the working day and record how much of the time the tool/ machinery is operating.

we need to know the daily duration of exposure to the

vibration from the vehicles or machines used.

Measurements

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instrument / calibration uncertainty;

variation of machine operators;

ability of the worker to reproduce typical work

environmental factors;

variations in the machine;

accuracy of source data

Factors of uncertainty (EN ISO 5349-2:2001 Part-2, EN 14253:2003)

Uncertainty of daily exposure evaluations

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• other working methods that require less exposure tomechanical vibration;

• the choice of appropriate work equipment producing theleast possible vibration;

• the provision of auxiliary equipment that reduces the risk ofinjuries caused by vibration, such as seats that effectivelyreduce whole-body vibration, handles or gloves whichreduce the vibration transmitted to the hand-arm system;

• appropriate maintenance programmes for workequipment, the workplace and workplace systems;

Reducing exposure

when action values are exceeded, the employer shall implement a program of technical and organizational

measures designed to minimize exposure, considering:

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• adequate information and training to instruct workers touse work equipment correctly and safely;

• limitation of the duration and intensity of the exposure;

• organization of appropriate work schedules;

• the provision of clothing to protect exposed workers fromcold and damp.

Reducing exposure

when action values are exceeded, the employer shall implement a program of technical and organizational

measures designed to minimize exposure, considering:

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If the exposure limit value is exceeded, the employer shall

take immediate action to reduce exposure below the

exposure limit value. He shall identify the reasons why the

exposure limit value has been exceeded, and shall amend the

protection and prevention measures accordingly in order to

prevent it being exceeded again.

comparison with limit values

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• the measures taken in order to eliminate or reduce to aminimum the risks from mechanical vibration;

• the exposure limit values and the exposure action values;

• the results of the assessment and measurement of the mechanical vibration and the potential injury arising from the work equipment in use;

• why and how to detect and report signs of injury;

• the circumstances in which workers are entitled to healthsurveillance;

• safe working practices to minimise exposure to mechanicalvibration.

Worker information and training

workers who are exposed to the risks from mechanical vibration at work must receive information and training

relating to the outcome of the risk assessment, concerning in particular:

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Risk assessment report

The technical report of exposure assessment to mechanical vibration of workers should include:

general premise (data and business description, equipment used, etc.);

list of equipment, personnel, duties;

brand and model of equipment subject to measure, working conditions;

presence of special conditions (noise, humidity, etc.);

instruments used for

measurements;

presence or absence of specific

working conditions

assessment of respect of

exposure values;

general conclusions with

indication of possible measures

for risk reduction.

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risk assessment and/or measurement must be up date atregular basis, by trained personnel within the SPP;

risk assessment must be immediatly updated when changes,that could render it out, or when the results of health surveillancewill show the need.

Risk assessment report

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Thanks for your attention

for any clarification, food for thought, notes:

[email protected]

hand arm and whole body vibrations exposure- directive...

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