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EDITORIAL BOARD

R. Parameswaran

W.A. Balakumaran

P. Manoharan

P. Subramani

G.S. Swaminathan

Printed at Sunitha Printers, Chennai – 600 014

VOL: 11 No. 4 OCTOBER – DECEMBER 2012

QUARTERLY JOURNAL OF SAFETY ENGINEERS ASSOCIATIONBlock III , Flat No. 28, Maanasarovar Apartments, 11-A, Arcot Road, Chennai – 600 116.

Tel : 044-24764101 E-mail: info@seaindia.org Website: www.seaindia.org

INDIAN SAFETY ENGINEERSEA (INDIA)

Inside....Page

NEBOSH Course Update 2

Hazards associated with

Foundry Operations 3

Modern Material Inspection

Techniques to detect

Voids & Cracks in the

Components 6

CASE STUDY 7

Detonation flame arrester 11

32nd Professional

Development Programme 12

IN THE NEWS 13

Safety takes back seat

New rules on e-waste to boost

resource efficiency in E U

Make road safety a social

movement

(Regn No: 1391 / 2000)[Registered under Societies Act, 1975]

FROM THE DESK OF PRESIDENTDear Members,

A collaborative programme on ‘H& S Risk Assessment’was jointly conducted with Regional Labour Institute,Chennai and Sri Ramachandra University at Chennaion 02nd & 3rd November 2012. Inspectorate of Factories,Govt. of Tamil Nadu supported the programme.

61st Executive Committee meeting of SEA was held on08th December 2012. 32nd Professional DevelopmentProgramme was held on 04th November 2012. Ourjournal “Indian Safety Engineer” for the third quarter 2012 was released inOctober 2012 and hopefully the next issue for the last quarter of 2012 will reachyou soon. We are trying to schedule a factory visit during early 2013.

Mumbai Chapter of SEA is witnessing some hiccups due to few of their officebearers leaving Mumbai for taking up assignments in other places. They areplanning to address these issues and elect new Coordinators for the Chapter intheir next Committee meeting scheduled in January 2013.

There are no further updates from our Hazira Chapter at Gujarat. However, SEA(India)’s next Chapter is now taking shape at New Delhi. A meeting was heldrecently and the constitution is in progress. Let us wish them good luck.

Eleventh Batch of NEBOSH, IGC course by SEA India was conducted in October2012, 20 members attended classes and wrote the examinations. Results havejust come in and most of them have passed out with good marks. Admissionsfor March 2013 batch are in progress.

SEA (India) website, www.seaindia.org is now fully functional. Members mayadvise their Service providers / vendors to advertise their products/services in theexclusive web page available in the site towards bringing in awareness amongmembers.

SEA Library is now set up and full list of these books are available at SEA Office.Suggestions are welcome from members towards making use of these wealth ofknowledge.

Wish you and your family members a Safe, Healthy and Prosperous New Year,2013

Best Wishes!

S. UlaganathanPresident, SEA (India)

SEA India wishes A HAPPY AND SAFE

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NEBOSH Course UpdateMr Robert Stynes, International Business Executive, NEBOSH, UK visited SEA India office on Tuesday,December 4th 2012 and discussed about the conduct of International General Certificate Course bySEA India. He appreciated our mode of conduct of the Course in India.

The Fourteenth batch of International General Certificate Course of NEBOSH is scheduled during March2013 at Sri Ramachandra University, Porur. The admission process for this course is in progress.

SEA India encourages its members and other safety professionals to pursue this course to enhancetheir professional knowledge and career prospects. All those aspiring to join this course are requestedto contact the Secretary, SEA India by mail, info@seaindia.org for getting admission.

Candidates of NEBOSH Course – October 2012 batch

Mr Robert Stynes with our office-bearers

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(Contd. on next page)

HAZARDS ASSOCIATED WITH FOUNDRY OPERATIONSNoise in Fettling and dressing ofcastings

Fettling and dressing (ortrimming) are the termstraditionally given to the finishingof castings to remove excess orunwanted metal, eg flashings,risers etc. It can include processessuch as grinding, chipping andshot blasting.

Hand-held tools such as grindersand chipping hammers, or fixedtools such as pedestal grindingmachines, linishers and bandsawsare traditionally used to removethe unwanted metal. Automatedfettling is becoming morecommon today in a variety of waysalthough until recentlyapplications have been limited.

Very high noise levels areproduced during fettling and mayexceed 117 dB(A). Personal noiseexposure levels of100-110 dB(A)have regularly been measuredduring routine fettling operationsin both ferrous and nonferrousfoundries. Exposure to dust(including free silica) andvibration are also significant inmany cases.

The risk to hearing at a noise levelof 110 dB(A) is high. Only fiveminutes' exposure is required atthis level for the daily personalnoise exposure of an unprotectedoperator to exceed the 90 dB(A)second action level of the Noise atWork Regulations 1989 of UK.

Hierarchy of noise reductionmeasures

The following hierarchy should befollowed to prevent hearingdamage: elimination of the noise

producing part of the process;implementation of adequateengineering controls to reducenoise levels; provision and use ofsuitable personal hearingprotection as an interim measureor to supplement the above.

In many cases measures used toreduce or control the risks tohearing from fettling noise willalso improve product quality andproductivity. Other health risks,such as those due to exposure tovibration and dust, may also bereduced.

Examples of measures

Elimination

A thorough reappraisal mayenable noise exposure to bereduced by improved design andcontrol of the casting process. Forexample, improved mould designcan eliminate or at leastsignificantly reduce the amount ofexcess metal required to beremoved after casting, thusreducing the need for fettling.

Engineering controls

Purchasing policy

Companies should operate apositive purchasing policy for newmachinery and ensure that noiselevels are acceptable beforeintroduction into the factory. Forexample, low-noise or noise-reduced grinding discs are nowavailable and can reduce noiselevels by around 5 dB(A). Exhaustsilencers can be fitted to somepneumatic tools. Low-noise blowguns are also available.

Automation

The introduction of automatic or

semi-automatic fettling, eg fettlingrobots, CNC grinding machines,cropping etc, will removeemployees from risk. Where thesetechniques are used noise levelscan often be further reduced byfitting acoustic guards orenclosures. Whether suchengineering controls arereasonably practicable will dependon the volume of product, thenature of the process involved,and the types of castingsproduced. Automation ormechanisation of fettling issteadily becoming a morepracticable and cheaper optionalthough mechanical fettling isstill likely to be required forintricate castings and where avariety of castings are produced insmall numbers.

Process modification

In some cases it may be possibleto substitute rough or even finishmachining for hand fettlingprocesses.

Example: Chipping hammers canbe replaced by grinders or linishersto achieve significant noisereductions. One of thecommonest noise sources is the airexhausts in pneumatic systems.Fitting suitable and low costsilencers can significantly reducethis noise. Metal on metal noisecan be avoided by coveringfettling bench worksurfaces withabrasion resistant rubber and byreducing impact noise fromcastings falling into stillages bymeans of lined chutes, or devicesto break the castings' fall. Theringing of castings being fettled

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Hazards ....(Contd. from previous page)

can be reduced by clampingworkpieces, by using rests onpedestal grinders, or by the use ofdamping devices. Finally, noise-reduced grinding discs areavailable.

Process control andmaintenance

Good process control is not onlyimportant for product quality andproduction efficiency but also as ameans of controlling noiseexposure. Careful attention to themaintenance of machinery andtraining of operators will make asignificant difference to noiselevels - for example: keepingcutting tools sharp; regularlydressing grinding wheels;replacing worn parts, damagedpatterns, mould boxes etc;maintenance of enclosures; repairof air leaks; tightening of loosenedmachinery panels.

Enclosure and separation

Acoustic enclosures or acousticguards can be fitted to someexisting machinery to reducenoise levels.

Example: The use of separatefettling booths, acoustically linedwith 75 mm mineral wool, willassist in reducing the personalnoise exposure of individualoperators and can give reductionsof up to 5 dB(A) in the additiveeffects of noise from adjoiningbooths.

Other measures

Further measures are availablesuch as the rotating of the fettlingwork among employees to keeppersonal noise exposures at acontrolled and reasonably lowlevel. For example, halving an

operator's exposure time willreduce exposure by 3 dB(A) thushalving the risk to the operator'shearing.

Personal hearing protection

The selection and use of suitablehearing protection should bebased on the results of the noiseassessment required under thevarious regulations.

In practice most manual fettlingoperations will require suitablehearing protection in addition tothe use of the other measuresreferred to above.

Control of SubstancesHazardous to Health duringFettling Operation

Hazard

• Fettling can produce respirablecrystalline silica (RCS).

• All RCS is hazardous, causingsilicosis. This is a serious lungdisease causing permanentdisability and early death.

• Silicosis is made worse bysmoking.

• ‘Respirable’ means that thedust can get to the deepestparts of the lung. Such finedust is invisible under normallighting.

• Keep inhalation of RCS as lowas possible.

• When all controls are appliedproperly, less than 0.1 mg/m3RCS is usually achievable(based on an 8-hour time-weighted average).

• Sand contains up to 100%crystalline silica.

Access and premises

Authorised persons alone can bepermitted to do any operation.

Equipment

• Can you use a shotblastcabinet?

• Control fettlings and dust.Fettle small castings in anextracted booth.

• Fettle very small castings usingan abrasive or wire wheel fittedwith dust extraction.

• You need an air speed between1 and 2.5 metres per secondinto the fettling booth, orbetween 2.5 and 10 metres persecond into abrasive area

• Fit a manometer or pressuregauge near the extractionpoint, to show that theextraction is working properly.

• Always confirm that theextraction is turned on and

working at the start of work.Check the gauge.

• Discharge cleaned, extractedair to a safe place outside the

Foundries: Silica – Engineering control

(Contd. on next page)

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Hazards ....(Contd. from previous page)

building, away from doors,windows and air inlets.

• Have a supply of clean aircoming into the workroom toreplace extracted air.

• Consult a qualified ventilationengineer to design new controlsystems and to update currentcontrols.

• Shake down air filters fourtimes a day.

• Fit an indicator or alarm toshow if filters have blocked orfailed.

Procedures

• Position the workpiece so thatit is as close as possible to theextraction point.

• Ensure that fettling dust isdirected into the booth andthat pneumatic tools do notblow dust out of the booth.

Maintenance, examination andtesting

• Follow instructions inmaintenance manuals - keepequipment in effective andefficient working order.

• Repair faulty extractionsystems as soon as possible.Meanwhile wear respiratoryprotective equipment (RPE).

• Fettlings are very abrasive andplant wears out quickly.Fettlings can block extractionpoints. Plan regularmaintenance.

• Every day, look for signs ofdamage. Noisy or vibrating fanscan indicate a problem.

• At least once a week, checkthat the extraction system andgauge work properly.

• You need to know themanufacturer's specifications tocheck the extraction'sperformance.

• If this information isn'tavailable, hire a competentventilation engineer todetermine the performanceneeded for effective control.

• The engineer's report mustshow the target extractionrates.

• Keep this information in yourtesting log-book.

• Get a competent ventilationengineer to examine theextraction thoroughly and testits performance at least onceevery six months.

• Keep records of allexaminations and tests for atleast five years.

• Carry out air sampling to checkthat the controls are workingwell

Personal protective equipment(PPE)

• Ask your supplier to help youget the right PPE.

Respiratory protectiveequipment (RPE)

• RPE is not normally needed forwork done inside a fettlingbooth. RPE may be needed formaintenance. If so:

• Provide RPE with an assignedprotection factor (APF) of atleast 10.

• Disposable RPE is acceptable -

throw this away at the end ofthe task.

• Otherwise replace RPE filtersas recommended by thesupplier.

Other protective equipment

• Provide coveralls that do notretain dust.

• Use a contract laundry orsuitable equivalent to washwork clothing. Warn them thatthe dust contains silica.Caution: Never allow use ofcompressed air to remove dustfrom clothing.

Health surveillance

• You need health surveillanceunless exposure to RCS is wellbelow the limit.

• Consult an occupationalhealth professional.

Cleaning and housekeeping

• Every day, clear up fettlings.

• Clean general workrooms oncea week to stop dust beingstirred up.

• Use a suitable vacuum cleanerfitted with a good filter to clearup dust.

Caution: Don’t use a brush orcompressed air.

Training and supervision

• Tell workers that fettling dustcan cause serious lung diseases.

• Working in the right way andusing the controls correctly isimportant for exposure control.Train and supervise theworkers.

DISCLAIMER: All information contained in this Journal, were obtained from sources, believed to be reliable and are collated, based ontechnical knowledge and experience, currently available with the Editorial Board of SEA (India). While SEA (India) recommends referenceto or use of the contents by its members and subscribers, such reference to or use of contents by its members or subscribers or thirdparties, are purely voluntary and not binding. Therefore the Editorial Board of this Journal or SEA (India) assumes no liability or responsibilitywhatsoever towards any bad or undesired consequences.

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MODERN MATERIAL INSPECTION TECHNIQUES TO DETECTVOIDS & CRACKS IN THE COMPONENTS

Industrial computed tomography(CT) scanning is a modernmaterial inspection techniquewhich uses X-ray equipment toproduce three-dimensionalrepresentations of componentsboth externally and internally.Industrial CT scanning has beenused in many areas of industry forinternal inspection of components.Some of the key uses for CTscanning have been flaw detection,failure analysis, metrology,assembly analysis and reverseengineering applications.

Types of scanners

Fan/line beam scanners-translate

Line scanners are the firstgeneration of industrial CTScanners. X-rays are produced andthe beam is collimated to create aline. The X-ray line beam is thentranslated across the part and datais collected by the detector. Thedata is then reconstructed tocreate a 3-D Volume rendering ofthe part.

Cone beam scanners-rotate

During the CT scan the part isplaced on a rotary table. As thepart rotates the cone of X-raysproduce about 1300 2D imageswhich are collected by thedetector. The 2D images are thenprocessed to create a 3D volumerendering of the external andinternal geometries of the part.

Analysis/inspection techniques

Various inspection techniquesinclude

Part to CAD comparisons, part topart comparisons, assembly / defectanalysis, void analysis, wallthickness analysis, and generationof CAD data for reverseengineering requirements andGD&T (geometric dimensioningand tolerance) analysis to meetPPAP (production part approvalprocess) requirements.

Assembly

One of the most recognized formsof analysis using CT is assembly orvisual analysis. CT scanning hasbeen largely used for medicalpurposes as an imaging tool tosupplement medicalultrasonography and X-rays as wellas for screening for disease andpreventative medicine. Forindustrial CT scanning, the abilityto see inside a component isbeneficial since internalcomponents can be seen in theirfunctioning position. Also, devicescan be analyzed withoutdisassembly. Some softwareprograms for industrial CTscanning allow for measurementsto be taken from the CT datasetvolume rendering. Thesemeasurements are useful fordetermining the clearancesbetween assembled parts or simply

a dimension of an individualfeature.

Part comparisons (part to part orpart to CAD)

In today's market parts can bemanufactured around the world:designed in one country, machinedin another and assembled in athird. Verification of the part tothe original CAD design is critical,especially if the part is to be usedin an assembly. Industrialcomputed tomography allows for acomparison of parts to one anotheror parts to CAD data. Thedeviations for both external andinternal geometries can be shownon the surface colour mapchromatically on the 3Drepresentation or by whisker plotsin the 2D windows. This process isbeneficial when comparing thesame part from various suppliers,studying the differences in partsfrom one cavity to another cavityfrom the same mould, or verifyingthe design to the part.

Void Analysis

Traditionally, determining anobject's porosity would requiredestructive testing. CT scanningcan detect internal features andflaws without destroying the part.Industrial CT scanning (3D X-ray)is used to detect flaws inside a partsuch as porosity, an inclusion, or acrack before a failure can occur. Insome software programs theporosity within a part iscategorized by colour based ontheir respective sizes.

Metal casting and moulded plasticcomponents are typically prone to

Line beam scanner

Cone beam scanner

(Contd. on next page)

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porosity because of coolingprocesses, transitions betweenthick and thin walls, and material

properties. Void analysis can beused to locate, measure, andanalyze voids inside plastic ormetal components.

Generation of CAD data forreverse engineeringrequirements

A CAD file can be generated fromthe CT data set, which isparticularly useful in reverseengineering applications andproduct development. ExportedCAD file formats are recognized bymany software such as CAD, FEA,Fluid Dynamics and Mold Flowsoftware. The CAD file created byCT scanning not only shows theexternal components, but theinternal as well. This allows forfirst-time rapid prototyping ofinternal components without thedaunting task of creating anentirely new CAD file.

Geometric dimensioning andtolerancing analysis.

Traditionally, without destructivetesting, full metrology has only

been performed on the exteriordimensions of components. If ahighly detailed componentrequires inspection, theconventional method of inspectionwould be to fixture the part tocreate specified datum referenceplane and go through a timelyCMM (Capability MaturityModel) touch-probe inspectionprocess or use a vision system tomap exterior surfaces. Past internalinspection methods would requireusing a 2D X-ray of the componentor the use of destructive testing.Industrial CT scanning allows forfull metrology of the CT datasetsallowing for an analysis of GD&T(Geometric Dimensioning &Toleraneing) points to meet thePPAP (Production Part ApprovalProcess) requirements.

Courtesy: Wikipedia

Flight through a 3D reconstruction of adisposable pepper grinder. Glass in blue.

Modern material....(Contd. from previous page)

CASE STUDYThe involved unit: Incinerationunit

Waste materials are received either inbulk or pre-packed and then movedto storage in designated zones:aboveground vats for liquids, ditchesfor solids and pastes.

For certain types of waste, it may bedecided to treat them by directinjection as an incineration processfrom the tanker truck parkedadjacent to the unit.

Waste is conveyed to the combustionfurnace intake and then to a rotaryfurnace. A pre-treatment step(drying) is applied to the sludgeaccording to its level of dryness, priorto introduction into the furnace.

The incineration process takes placeover several stages: combustion,cooling of gasses, and gas treatment.

Diagram of the incineration process

Fume purification residues are then conveyed to the site's stabilisation-solidification unit.

(Contd. on next page)

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Waste acceptance protocol:The onsite acceptance protocol forhazardous wastes is as follows:• The first step consists of

identifying and characterising thespecific type of waste before itsarrival onsite, by means of arepresentative sample furnishedby the waste producer, andoffering judgment on wastesuitability depending on both itscharacteristics and the site'scapacity to provide treatment. Apreliminary acceptancecertificate is then sent to theclient and an appointment set toreceive the waste.

• Upon its arrival onsite, theshipment of waste must beaccompanied by a waste trackingslip. Compliance of this slipalong with the acceptancecertificate is verified and asample extracted for analysis inorder to ensure a match betweenthe waste received and thecertificate and tracking slipdetails, ultimately with the aim ofconducting specific analyses torefine treatment. The package ofwaste is then transferred to theappropriate installation.

Feeding the furnace with liquidwaste: The liquid waste is conveyedto the point of furnace injection bymeans of a set of pumps and rackedpipes. The distribution array, laid outadjacent to injection points, feeds theinjection tubes where the liquid ispulverised by compressed air. Foreach line of waste, the arrayrecomposes the flow measurementand safety sectioning instruments.Each flow rate is automaticallyadjusted on the basis of furnaceoperating parameters.The Accident, its chronology,Effects and ConsequencesThe accident:Waste acceptance: The waste at the (Contd. on next page)

Diagram of the fume treatment process

origin of this accident was a mix of30% hydrogen peroxide and 5% acidresins; it was the by-product of anunloading error that occurred withinthe paper mill complex .. This errorcaused an exothermic reaction of themix and necessitated the onsitepresence of local fire and emergencypersonnel along with evacuation ofthe entire plant.The waste processing centre wasasked to undertake the immediateremoval of 40 tonnes of wasteinvolved in this incident; due to alack of detailed information, thecentre initially refused the request.After analysing a waste sample andstabilising the waste at roomtemperature, the centre agreed to anincineration-based treatment bydirect injection into the furnace. Apreliminary acceptance certificatewas issued .In an e-mail message , the paper millrequested the processing centre tosuspend the outlined waste removalprocedure since the mill wasstudying the feasibility of an in-houseneutralisation solution as a means oflimiting reprocessing costs. Followinginvestigation, it was clear thatneutralisation tests conducted onseveral samples of these wastes, at the

production site, were not conclusive.The mix contained in two of the vatswas pumped on into a stainless steel,single-compartment tanker truck.The first vat could be completelyemptied and the second to a partialextent.The waste was delivered to theprocessing centre . A sample wasextracted and, following acceptance,the tanker truck was routed to thesite's direct injection zone forunloading into furnace no. 1.Chronology of events:At 3:52 pm, the tanker truck arrivedat the site.At 5:45 pm, the direct injection linewas rinsed with water before beingconnected to the tanker truck.At 6:15 pm, incineration operationsbegan.At 9:00 pm, the direct injection linewas obstructed. It was unplugged andnitrogen was injected via a vent onthe truck, in an effort to "push" thewaste through. The truck's valve wasleft open.The next day, at 3:00 am, leaks onthe truck's second manhole were stillongoing. The incineration operationwas halted. The underflow gate was

Case Study....(Contd. from previous page)

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Case Study....(Contd. from previous page)

closed and the nitrogen injectioncircuit isolated, yet the hoseconnecting the tanker truck to thedirect injection pump was stillhooked up to the truck.At 4:00 am, the hose connecting thetruck to the injection pump burst.The truck at this point was "veryhot".At 5:30 am, the truck was still "hot".At 8:30 am, the temperature of thetanker truck sidewall was estimatedat between 30°and 60°C. The ve ntswere open and the truck wassprinkled by the spraying rampslocated in the zone dedicated todirect processing operations.By 12:00 noon, both the trucktemperature and pressure were rising.The truck was moved outside thedirect processing zone to install a"peacock fan"-shaped spraying deviceon each side of the truck. The valveon the site's industrial effluent andstormwater containment pond wasthen closed.Around 1:30 pm, teams on the site'ssecond shift arrived as a backup tocontinue spraying the tanker truckwith fire hoses. In order to lowerpressure, the truck was emptied of afew containers loaded with the mix,and these containers were placedadjacent to the truck. A safetyperimeter was established.The onsite teams chose to set up awater cannon in order to protectpersonnel from exposure. It was thendecided to move the personnel tosafety and call the emergency servicesunit.At the same time, 2:30 pm, theinternal tanker truck pressure roseand the manhole located on the backface of the truck broke open. Thetruck degassed all at once; then, boththe truck and tractor were propelledsome fifteen metres due to the effectof this pressure burst and came to restwhen reaching the edge of the track.

Consequences of the accident: Justafter the accident, a local evacuationnotice for the zone was broadcast.Staff members at the nearbylaboratory were evacuated to anotherzone on the same site, whereas officeemployees were told to remainindoors and not allowed to leave.Vehicle entrance bays were shut. Asafety perimeter was marked offaround the tanker truck. Truckcooling was facilitated using a firehose. A message announcing the endof this alert was broadcast .Three employees were slightly hurt:facial irritations, and a partial footburn; they were all taken to hospital.Nine other people showed up at thesite infirmary with benign injuries.No major property damage wasdeclared (deformation of some metalcladding), except for the tanker truckitself, whose braces and hood werebent.The quantity of mix released into theatmosphere, in the form of dropletsand O2 remaining from peroxidedecomposition, was estimated at lessthan a tonne (approx. 600 litres).The Origin, Causes andCircumstances surrounding theAccidentWaste pumping at the productionsite: The paper mill indicated thatit had not modified the waste duringneutralisation testing conductedsolely on samples and moreover hadnot noticed any heating during wasteloading into the tanker truck. The

Photographs of the tanker truck and the various spraying set-ups(reconstitution - Source: site operator)

pumping stage using new hoses wascarried out onsite.Inspection of tanker truck contentsupon arrival: The sample taken fromthe truck, for the purpose ofdeclaring acceptance or not at theprocessing site, was similar incomposition to the one received forpreliminary acceptancedetermination, yet showed slightinstability (a few bubbles that werenot mentioned on the materialtransfer form). Truck temperaturewas not verified by the samplingtechnician. The material transferform listed the results of analysesperformed and confirmed routing tothe direct incineration unit. Thetractor then towed the tanker truckto the required spot (direct treatmentzone) and left it there.Preparation for the incineration step:Racking of this tanker truck couldnot begin immediately since theinjection line was already in use foranother vat. The incineration unithad been forewarned of the need touse a clean set of bleeding lines andbuckets. The direct injection lineswere rinsed with water prior toinitiating tanker truck pumping.Origin of degassing: Thedecomposition of hydrogen peroxideled to a sudden degassing of thetanker truck. The H2O2decomposition reaction is anexponential speed reaction. Definingwith certainty the exact time whenthe product starts to react proves to

(Contd. on next page)

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be a difficult step, since inertia runshigh in a tanker truck carrying 25tonnes. This reaction was in fact ableto begin prior to waste acceptance:before/during loading, at the sametime as the transport?A number of questions still remain:-The waste was able to undergomodifications during treatment testsconducted by the producer, betweenthe date of sample transmission andthe date of waste acceptance;-The mixing of both vats at the timeof pumping also served to trigger thereaction. This information relative tothe two-vat mix was only receivedafter the accident at the processingcentre.On the following day, an additionalsample was extracted from the truckas the temperature inside the truckwas starting to climb. This samplerevealed a lower H2O2 rate thanthat recorded the day before, whichconfirms a progression in thereaction, yet the analysis wasundertaken following the accident.The incineration unit had beenadvised to use clean bleeding linesand buckets but had not beenformally notified by the laboratory ofan eventual risk of pressure rise.The unloading method employed didnot enable coping with the risk ofwaste degassing:-The selected unloading line wasoperated by either suction ornitrogen thrust; it lacks a specificrelief valve system that could haveallowed releasing the gas formedduring the reaction;-Only the tanker truck valves couldhave ensured proper aeration and therequisite evacuation of gas bubbles;these valves however provedinadequate for this particular wastewithin this particular volume.Internal Emergency PlanThe Internal Emergency Plan hadnot been activated since the various

scenarios did not feature eitherhydrogen peroxide degradation or atanker truck rupture as theconsequence of an uncontrolledchemical reaction; the situation didnot present any fire or explosion riskand the toxic risk was controlled bywater curtains. Nonetheless, the setof actions actually initiated inresponse to the event did correspondto the measures indicated in thisemergency plan.ACTIONS TAKENImmediate measures adopted:In order to avoid and limit theconsequences of a similar accident,the operator decided to:– introduce the systematic

verification of tanker trucktemperature at the time ofmaterial acceptance (with allpertinent information recordedon the material transfer form);

– refuse the acceptance of wastescontaining hydrogen peroxide inbulk packaging exclusively forconcentrations below 5%, andrequire wastes containing higherconcentrations to be shipped inbarrels or containers.

Prescriptions issued, request forremedial actions:Inspection authorities stated that theset of measures specific to theinternal emergency plan establishedby the Prefectural order approvingthe site were not respected.Non-activation of the emergencyplan meant that the fire and rescueunit was not informed and moreoverthat the unit's technical resourceswere not mobilised to prevent theexacerbation of an accidentalsituation. More specifically, air qualitymeasurements in the vicinity of thetanker truck, in the case where thetruck had been degassing for severalhours, were not completed.Subsequent to this accident, anumber of site safety managementsystem improvements wereanticipated: re-evaluation of waste

acceptability controls (including thephysical magnitudes that enabletracking a potential evolution inloading behaviour), assessment ofrisks relative to tanker truck parkingnear industrial installations and high-risk zones, and reexamination of thedecision-making process that leads toactivation of the internal emergencyplan.LESSONS LEARNTThe primary cause of the suddentanker truck degassing was thedecomposition reaction initiatedwithin the waste contained in thetruck. The accident analysis hasshown however that not only werethe waste material acceptabilitycontrols insufficient, but the safetymeasures in place at the time wereinappropriate.The treatment of hazardous wasterequires a safety management systemthat includes the following:– characterisation of the targeted

materials (pH, temperature,colour, viscosity, odour, etc.),controls and testing for chemicalcompatibility betweensubstances, verification of theabsence of phases within the mix,and any immediate undesirablechemical reaction or deviation inmaterial characteristics overtime;

– assignment of responsibilities tobe more clearly specified andadapted to all operations plannedby personnel or contractorsinvolved at the processing site;

– technician training in hazardprevention, specifically for thesteps of material unloading andtransfer (with the possiblepresence of residual toxic orinflammable gas, etc.);

– indications of measures to beadopted in the event of anincident or deviation in operatingprocedure;

– introduction of measurement,detection and monitoringdevices.

Case Study....(Contd. from previous page)

11

DETONATION FLAME ARRESTER

A detonation flame arrester is adevice fitted to the opening of anenclosure or to the connecting pipework of a system of enclosures andwhose intended function is to allowflow but prevent the transmission offlame propagating at supersonicvelocity and characterized by a shockwave. ( designed to prevent thetransmission of a detonation).

Detonation Flame Arrester productswere created in response toenvironmental regulations (such asThe Clean Air Act) which requiredliquid product storage terminals andhydrocarbon processing plants tocontrol evaporative hydrocarbonemissions from loading and storageoperations. This process is calledvapor control. Two types ofrecognized vapor controltechnologies are commonly used;carbon adsorption vapor recoveryand vapor destruction or combustion.Vapor destruction systems includeelevated flare systems, enclosed flaresystems, burner and catalyticincineration systems, and waste gasboilers. Both systems require flame ordetonation flame arresters tomaximize safety. Detonation flamearresters are used in many industries,including refining, pharmaceutical,chemical, and petrochemical, pulpand paper, oil exploration andproduction, sewage treatment,landfills, mining,power generation,and bulk liquids transportation.

How Detonation Flame ArrestersWork?

Flame arresters are passive deviceswith no moving parts. They preventthe propagation of flame from theexposed side of the unit to theprotected side by the use of metalmatrix creating a torturous pathcalled a flame cell or element. Alldetonation flame arresters operate onthe same principle: removing heatfrom the flame as it attempts to travel

through narrow passages with walls ofmetal or other heat-conductivematerial, but unlike flame arresters,detonation flame arresters must bebuilt to withstand extreme pressuresthat travel at supersonic velocities,1,500 psia @ 2500 m/sec is notuncommon with a group D Gas.

Detonation flame arresters made bymost manufacturers employ layers ofmetal ribbons with crimpedcorrugations. The internal narrowpassages of the crimped corrugationsmake up the element matrix. Thesepassages are measured as thehydraulic diameter and are madesmaller for gases having smallermaximum experimental safe gaps(MESG).

Under normal operating conditionsthe flame arrester permits a relativelyfree flow of gas or vapor through thepiping system. If the mixture isignited and the flame begins to travelback through the piping, the arresterwill prohibit the flame from movingback to the gas source.

Most detonation flame arresterapplications are in systems whichcollect gases emitted by liquids andsolids. These systems, commonly usedin many industries, may be calledvapor control systems. The gaseswhich are vented to atmosphere orcontrolled via vapor control systemsare typically flammable. If theconditions are such that ignitionoccurs, a flame inside or outside of

the system could result, with thepotential to do catastrophic damage.

A flame arrester or flame trap is adevice that stops fuel combustion byextinguishing the flame.

Usage and applications

Flame arresters are used:• to stop the spread of an open fire• to limit the spread of an explosive

event that has occurred• to protect potentially explosive

mixtures from igniting• to confine fire within an enclosed,

controlled, or regulated location

They are commonly used on:• fuel storage tank vents• fuel gas pipelines• safety storage cabinets for paint,

aerosol cans, and other flammablemixtures

• the exhaust system of internalcombustion engines

• Davy lamps in coal mines• overproof rum and other

flammable liquors.

Principles

A flame arrester functions by forcinga flame front through channels toonarrow to permit the continuance ofa flame. These passages can beregular, like wire mesh or a sheetmetal plate with punched holes, orirregular, such as those in randompacking.

Detonation Flame Arrester is beingtested for an 8 inch piping system

Detonation Flame Arresters forvarious pipe sizes

(Contd. on next page)

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The required size of the channelsneeded to stop the flame front canvary significantly, depending on theflammability of the fuel mixture. Thelarge openings on a chain link fenceare capable of stopping the spread ofa small, slow-burning grass fire, butfast-burning grass fires will penetratethe fence unless the holes are verysmall. In a coal mine containinghighly explosive coal dust ormethane, the wire mesh of a Davylamp must be very tightly spaced.

For flame arresters used as a safetydevice, the mesh must be protectedfrom damage due to being dropped or

struck by another object, and themesh must be capable of rigidlyretaining its shape during a forcefulexplosive event. Any shifting of theindividual wires that make up themesh can create an opening largeenough to allow the flame topenetrate and spread beyond thebarrier.

On a fuel storage vent, flamearresters also serve a secondarypurpose of allowing air pressure toequalize inside the tank when fuel isadded or removed, while alsopreventing insects from flying orcrawling into the vent piping andfouling the fuel in the tanks andpipes.

Detonation....(Contd. from previous page)

Safety

Flame arresters should be used onlyin the conditions they have beendesigned and tested for. Since thedepth on an arrester is specified forcertain conditions, changes in thetemperature, pressure, orcomposition of the gases entering thearrester can cause the flame spatialvelocity to increase, making thedepth of the arrester insufficient tostop the flame front ("flow"). Thedeflagration may continuedownstream of the arrester.

Flame arresters should be periodicallyinspected to make sure they are freeof dirt, insects using it as a nest, orcorrosion.

32ND PROFESSIONAL DEVELOPMENT PROGRAMME

Introduction:

Safety of men and material is ofvital importance for unhinderedexecution of activities at site andtimely completion of project.Everyone associated with the workregardless of his/her position orstatus, has the responsibility of his/her own safety and safety of peopleworking around him/her.

Accident and injury cause pain,misery, loss of earning and hardshipnot only to the injured person, butalso to his / her family. No one,therefore wants to get injured,instead wants to return home inthe same condition in which he/shecame every day. This is howeverpossible only if everyone followed

Thirty Second Professional Development Programme Was held on Sunday, 4th November 2012 at Chennai.

Mr. C.N. Rathinam, Project Construction Manager and Mr. Shyam Thanigachalam, Safety Manager, M/s TataConsulting Engineers Ltd, Chennai delivered the talk on, “Project Safety Management.”

The meet was followed by lunch and presentation of certificates to the participants and a gift to the lucky winneramong the participants.

Large number of SEA India members participated and enriched their knowledge on safety management. The salientfeatures discussed during the programme is given in this article for the benefit of the members who could not participatein the programme.

the safety requirements all thetime.

While it is the responsibility ofmanagement to provide safeworking conditions at work place itis the duty of all associated with thework to earnestly follow the safetyrules, norms, standards andprocedure and not to indulge in anyunsafe act or practice and be causefor creation of unsafe condition.

To Achieve "Zero Accident "atwork place an effective projectsafety management must befollowed in the project.

Stage of Project SafetyManagement

1. Design Phase.

2. Procurement Phase.

3. Construction andCommissioning phase.

Design

Safety in design stage cancontribute to the elimination ofhealth and safety hazards inconstruction, from the earliest stageof the project. Safety considerationin design stages increases theproductivity (early completion ofproject in time) and reduces delayin time due to accident.

o Design options.(usuage of safematerial/equipment)

o Incorporation of safetyrequirements as per statutoryregulations.

(Contd. on next page)

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o Layout review (variouslocations and configurations).

o Construability review.

o Fire Fighting System,Emergency Response Plan etc.

Procurement Phase:

As work execution at site isgenerally carried out by contractorin due care shall be exercised fortheir proper selection, dulyconsidering their past performance(safety record) resource with regardto trained manpower, safetyappliance, their understanding ofclients requirement and inclusionof safety clause in the contract andeffective contract management.

• Prequalification of vendors onsafety ability.

• Site Visit to conduct safetyevaluation of vendors.

• Tender documents includedwith safety requirements.

• Pre-bid meeting with vendorson safety requirements.

• Issuance of purchase order.

Construction and CommissioningPhase:

The construction andcommissioning stage site specificsafety plan sets out thearrangements for securing thehealth and safety of everyonecarrying out the work andachieving "Zero accident " and Itdeals with

• Safety Kick of Meeting.

• Work methodology and Jobsafety analysis.

• Training requirements for theproject.

• Monitoring of Safety Inductionand Tool box talks.

• Permit to work.

• Safety communication.

• Inspection system.

• Emergency response procedure.

• A c c i d e n t / I n c i d e n tInvestigation.

• Safety Audit.• Safety reward program.

Conclusion:

With project safety managementbeing followed from design tillcommissioning stage to achieve"Zero accident" it has been veryuseful in estimating:

• Budget requirement for Plantand Machinery (materialhandling and Logistics).

• Safe process operation system.• Skill requirements for the job

activity (Included in selectionof contractors).

• Co ordination requirements forthe job activity.(Sequencing ofwork activity for multiplecontractors).

• Reduction of project schedule(by using latest engineeringtechniques).

32nd Professional....(Contd. from previous page)

Safety takes back seat

It is very disheartening that in spite of several laws, codes and stipulations by the government, weare witnessing so many accidents.

The need of the hour is to spread safety awareness so as to instil confidence in people that thegovernment is very clear about enforcing all laws and regulations to avoid accidents.

The main focus areas are homes, where gadgets like LPG stoves, induction heaters and microwaveovens, if not used safely, could lead to serious accidents. The international precautionary indicationis that LPG is strongly blended with smelling agents so that leaks are detected, but due to a lackof knowledge and awareness, timely action is not taken, resulting in nasty accidents and loss of lives.

Use of substandard electrical wires and switches, inserting wires into sockets without plugs and improperearthing are the main reasons for accidents due to electricity. It is advisable to use appliances ofstandard makes and which are BIS marked. The placing of air conditioners in the correct positionsand using non-flammable switch boxes would avoid mishaps. The use of ELCBS and flame-proof wiringwill assure us of safety from electric shocks at homes.

Courtesy: The Hindu

IN THE NEWS

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IN THE NEWS

New rules on e-waste to boost resource efficiency in E U.Improved rules on the collection and treatment of e-waste enter into force in European Union.E-waste (i.e. waste electrical and electronic equipment, or WEEE) is one the fastest growing wastestreams, and it offers substantial opportunities in terms of making secondary raw materials availableon the market. Systematic collection and proper treatment is a precondition for recycling materialslike gold, silver, copper and rare metals in used TVs, laptops and mobile phones. The new Directiveis a clear step forward in terms of environmental protection and a major boost to resource efficiencyin Europe.

Environment Commissioner Janez Potocnik said: “In these times of economic turmoil and rising pricesfor raw materials, resource efficiency is where environmental benefits and innovative growthopportunities come together. We now need to open new collection channels for electronic waste andimprove the effectiveness of existing ones. I encourage the Member States to meet these new targetsbefore the formal deadline.”

The Directive entering into force introduces a collection target of 45 % of electronic equipment soldthat will apply from 2016 and, as a second step from 2019, a target of 65 % of equipment sold, or85 % of electronic waste generated. Member States will be able to choose which one of these twoequivalent ways to measure the target they wish to report. From 2018, the Directive will be extendedfrom its current restricted scope to all categories of electronic waste, subject to an impact assessmentbeforehand.

The Directive gives Member States the tools to fight the illegal export of waste more effectively. Illegalshipments of WEEE are a serious problem, especially when they are disguised as legal shipmentsof used equipment to circumvent EU waste treatment rules. The new Directive will oblige exportersto test whether equipment works or not, and provide documents on the nature of shipments that couldbe thought illegal.

Make road safety a social movementUnion Minister for Road Transport and Highways, has urged state Chief Ministers to take RoadSafety a social movement in partnership with schools and universities.

In letters sent to Chief Ministers , the Union Minister has sought their cooperation in this endeavourby organizing road safety related activities in their state on a large scale especially in school/collegesso that the youth get sensitized on the issue.

Keeping in view the theme for Road Safety Week this time "Stay Alive, Don't Drink and Drive" theMinister has asked for spreading awareness against drunken driving.

He has also promised his Ministry's financial assistance, up to Rs. five lakh per state for organizingroad safety related activities in schools. These activities may include debates/painting and essaycompetitions/rallies and other such events with token prizes/ certificates.

In order to spread road safety awareness "Road Safety Week" is observed all over the country inthe month of January every year.

The ensuing 24th road safety week will be celebrated from January 1 to January 7 2013. The themefor Road Safety Week this time is "Stay Alive, don't drink and drive". The emphasis will be on spreadingawareness against drunken driving.

During Road Safety Week, States/UTs/NGOs and other stake-holders/agencies involved in road safetyundertake various activities aimed at inculcating/promoting road safety.

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Mr S Ulaganathan, President, Mr N Kumar, Secretary, Mr C N Rathinam, Project Construction Manager, and Mr ShyamThanigachalam, Safety Manager during the 32nd Professional Development Programme held on 04-11-2012 at Chennai

Mr S Ulaganathan, President, SEA India, Dr R K Elangovan, Director In-charge, Regional Labour Institute, Chennai, Dr K VSomasundaram, Dean of Faculties, S R U, Dr Kannan Krishnan, University of Montreal, Canada and visiting Professor to S R U,and Dr S Sankar, Head of Environmental Health Engineering Dept, S R U in the National Workshop conducted jointly by S R U, RL I and SEA India at SRI Ramachandra University, Porur on the topic “Current Concepts& Tools in Occupational Health & Safety RiskAssessment” on November 2 & 3, 2012

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