Article I Peter Wilson, Industrial Noise and Vibration Centre

Hearing Protection

76 Health &Safety International j January 201;

The common assumption that PPE isa reliable solution to hearing damagerisk problems is simply untrue, leavingmany personnelstillat risk and manycompanies open to claims. PeterWilson of the INVC summarises the

results ol the research and outlines

the key factors required to maketaring conservation programmes as

effective as possible.

The research -most hearingprotection isinadequateDespite the emphasis on noisecontrol in the new noise regulations,hearing protection is often (wronglv)considered to he the first and onlyline of defence against the risksofhearing damage.

Newresearch published in the UKby the HSE (RR720 2009), however,indicates that only40% of PPE usersret anyprotectionwhatsoever andthat the real world performance of asubstantial proportion ol theremaining 60%is inadequate.Companies must become aware thatissuing PPEis not a simple orreliable solution.

The following isa summary of themain findings of the research basedon both company visits and onlaboratory testing.

No protection

Ihe HA- oj'PPli in25%ofthecompanies visited was so ineffective thatis was likely toresult in negligible or noprotection for most users

Even in companies with generallyeffective hearing protector use, 14% ofthe workers did not wear protectors whenandwhere it was required

Overall, 40%of the workers who shouldhave been wearing protectors got noprotection at all

DavidSText BoxReproduced from Health &Safety International January 2012, with the kind permission of the Author

"glove choice may well havebecome over simplified, so thatyou just purchase on the basis ofit being latex or nitrile"

gloves and to emphasise that thesegloves are designed only forincidental exposure to chemicalsplashes. EN 574: 2003 hasgiven usa new pictogram.

The question mark in the middle ofthe square-shaped glass beakerreminds those of us engaged in riskassessments that weare referringto'low chemical resistant' or

'waterproof gloves. Significantly,there is noobligation for themanufacturer to undertake any

testingon the 12 listed chemicalsand the new pictogramonlv tells usthat the gloves have fulfilled thepenetration test (EN374-2: 2003).

While it is prudent to seekadvicefrom the manufacturer on actual

breakthrough times with a particularchemical, weshould not forget thatthis test data will often be based on

deep immersion of the "love into thechemical and therefore may notoffer a realistic representation of awork situation where the locus is on

splash protection.

Also, it should be noted that anytestdata is likely to be doneon anunused glove and does not reflect theactual workplace situation, where theused "love is subjected to many

other stresses that are beyond thescope of a simple laboratory test.

EN374-2: 2003 (determination of

resistance to penetration bv chemicalami/or micro-organisms throughporous material). An important testfor those using disposable gloves toprotect themselves from microorganisms, as it gives us an indicationol the barrier properties ol the gloveto liquid-borne biohazards.

lor most disposable gloves, the waterleak test is used, whereaccording tothe inspection level basedon ISO2859 a specified numberof glovesfrom every batch are filled with

water to assess the levels of pinholes.Levels of pinholes are measured interms ol AQL or Acceptable QualityLevel, with an AQE of 0.65 having alower level of acceptable pinholesthan 4.0. lb display the pictogramand as part of the process lor

Gloves I Article

satisfying a Complex Designregistration, gloves must haw aminimum AQE ol 1.5. EN374-2:

2003 describes the levels, which are

often displayed underneath thepictogram (Table 3).

ConclusionsAs you will have already appreciated,choosing a glove is difficult whenthere issuch a vast jungle ofavailableproducts. Glove choice may wellhave become oversimplified, so thatyou just purchase on the basis ol itbeing latex or nitrile, powdered orpowder-free and depending on price.

For practical ami economic reasons,often the users select justone glove.Abetter strategy might be to use twoor three different gloves to coverallthe needs you are likelv to encounter

in the workplace. Ibis approach islikelv to better optimise the balancebetween protection and cost orcomfort and cost.

llibhmograpny

EN374-I:2003 Protective gloves againstchemicals ami micro-organisms Pan I:

Terminology and performance requirements

EN374-2:2003 Protective gloves againstchemicals and micro-organisms Part 2:

Determination of resistance topenetration

E\:37-l-3:2003 Protective gloves againstchemicals and micro-organisms - Part 3:

Determination ofresistance topermeation bv

chemicals

EM420:2003 + A1:2009 Protective glovesGeneral requirements and test methods

Author Details:

Mick Gardner. MBA

E: nkk.gardner(

The main factors implicated in theseresults were:

Tea group pressure and groupbehaviour plus reluctance ofsupenisorsto enforce wear

The need to hear traffic, radios anddifficulties in communicating

Attitude - viewing PPE asan impositionwithout adequate consultation

Incorrectfitting (e.g. foam plugs)

Use of PPE as the sole control

measure without a comprehensive noisecontrol programme

Inadequate protector pro\ision

Thinkingbeyond PPECompanies must becomeaware thatissuing PPE is not a simple orreliable solution.

Inadequate protection

Less than 5096ofcompanies hadselected PPE based on the attenuation

actually required; consequently, abouthalfofthese had specified PPE thatover-protected

There was ignorance ofthe need toproride a choice ofPPE ina numberofcases

Adequate protection

Hearing protection was effectiveJor mostworkers in the 40%ofcompanies whoused PPE within a comprehensive noisecontrol programme (noise controlmeasures and 'Buy Quiet' policy)

PPE was most effective in companies whocombined training with appropriatesupervision and employee cooperation

Unnecessary protection

Making whole buildings orsites hearingprotection zones when only limited areasarenoisy

Requiring the use ofPPE e\er)i\hererather than assessing the actual risk

Hearing Protection I Article

"companies must become awarethat issuing PPE is not a simple orreliable solution"

PPE fieldperformanceissuesEarmuffs - The standard HSE

recommendation has been to de-rate

the manufacturers' attenuation data

bv 4dB to account for 'real world'

performance. The laboratory testing,however, showed an additional 6dB

loss after a simulated month of

normal use, primarily caused bystretching of the headband which isinvisible to the user. This means

that nearlya third of the earmuffusers seen would have been

under-protected.

Damageto earmuff seals is moreobvious, but removing an eighth ofthe seal showed a drop in attenuationol only 2dB. The effectiveness of theseal isalso compromised bvglasses,goggles and dust masks. The lessbulky versions reduce the attenuation

bv around 2dB, the bulkier versions

bvup to lOdB. Moreover, wearingearmuffs over clothing (e.g. hoods incold weather), reduced the

performance bv 14 - 21dB.

Earplugs - Proper fitting is the keyfactor. Just over 50% of the

compressed foam earplugusers seenhad not inserted the plugs properlyand most of them were ignorant ofthe correct fitting procedure.Simulated tests showed that the

attenuation could fall to as low as

9dB if not properly fitted. Usersgenerally preferred push-in plugs(foam or Range), as they are easier to

fit and were usually inserted deeperinto the ear canal. Banded ear canal

capsgave negligible protection underband pressure - they have to beinserted into the ear canal entrance.

While custom moulded earplugswere generally considered bycompanies and users to be the bestavailable, not all users found them

comfortable. While not included in

the laboratory testing for the report,previously published information hasindicated that the attenuation can fall

by up to 6dBover the first hour ofuse due to temperature effectschanging the shape of the ear canal.

Hearingconservationprogramme -best practiceThe following is a pragmatic guideto the key features that should beincluded in order to minimise

the risks to staffand potentialfuture claims.

1 Noise control programme

The HSE research showed that

hearing protection was mosteffective in those companies whereit was implemented as part of acomprehensivenoise controlprogramme. This is largely due tothe cultural and managementattitude engendered by the process- an unwillingness simplyto try tooffload responsibility (in the formol PPE) onto the workforce. In

January 2012 Health & Safety International 77

Article I Hearing Protection

addition, PPE. cannot be used for

lon term risk manaement unless

youcan prove that noise control isnot practical.

Consequently, companies mustassess the costs and benefits

associated with implementing aneffective control programme basedon the best ol current technology.This requires a noise controlaudit. This is an engineeringevaluation ol the noise control

options, costsand benefits carriedout either as part of a NoiseManagement Assessment, or as anadd-on to an existing assessment

where the competent person doesnot possess the required specialistengineeringexperti.se. In manycases, lowcost engineeringnoisecontrol techniques are availablethatcan provide the bonus of apotential pav-back due to