METAL FUME RISK EVALUATION

METAL FUME RISK METAL FUME RISK EVALUATIONEVALUATION

HOW TO TARGETHOW TO TARGETHOW TO TARGET HOW TO TARGET AIR SAMPLING AIR SAMPLING

IN ELECTRIC POWER PLANTSIN ELECTRIC POWER PLANTS

Challenges for Industrial Health Challenges for Industrial Health T h i iT h i iTechnicians Technicians

►►Finding and measuringFinding and measuring high fumehigh fume►►Finding and measuringFinding and measuring high fume high fume exposure activities is difficult. exposure activities is difficult.

►►These activities are inherently sporadic, These activities are inherently sporadic, not continuous.not continuous.

►►Schedules are unpredictable.Schedules are unpredictable.W kfW kf tt ii►►Workforce Workforce may notmay not recognize or recognize or communicatecommunicate high fume exposures.high fume exposures.

THE WRONG WAYTHE WRONG WAYTHE WRONG WAYTHE WRONG WAY

►►Pick a crew at Pick a crew at randomrandomrandom.random.

►►“Hey, can we “Hey, can we take some air take some air samples?”samples?”

THE RIGHT WAYTHE RIGHT WAYTHE RIGHT WAYTHE RIGHT WAY

►►Inquire at top andInquire at top and►►Inquire at top and Inquire at top and bottom of bottom of organizationsorganizationsorganizations.organizations.

►►Look for highest Look for highest fume rates not justfume rates not justfume rates, not just fume rates, not just “welding” in “welding” in generalgeneralgeneral.general.

HIGHEST FUME EXPOSURESHIGHEST FUME EXPOSURESHIGHEST FUME EXPOSURES HIGHEST FUME EXPOSURES OCURR DURINGOCURR DURINGOCURR DURINGOCURR DURING

THERMAL CUTTINGTHERMAL CUTTING►►AirAir--Arc cutting and gougingArc cutting and gouging►►Plasma Arc cuttingPlasma Arc cutting►►OxyOxy--Fuel “flame” or “oxygen” cuttingFuel “flame” or “oxygen” cutting►►OxyOxy Fuel flame or oxygen cuttingFuel flame or oxygen cutting►►Worst during Worst during demolition demolition oror teartear--downdown

EXAMPLE: CrEXAMPLE: Cr--6 RESULTS ON 6 RESULTS ON 304 STAINLESS STEEL304 STAINLESS STEEL304 STAINLESS STEEL304 STAINLESS STEEL

►►AirAir--Arc Gouging =Arc Gouging = 10 x PEL10 x PEL►►AirAir Arc Gouging = Arc Gouging = 10 x PEL10 x PEL

Pl C ttiPl C tti 5 PEL5 PEL►►Plasma Cutting = Plasma Cutting = 5 x PEL5 x PEL

►►Compare to 309 stick weld = Compare to 309 stick weld = 1.5 x PEL1.5 x PEL

►►Other fumes follow similar pattern.Other fumes follow similar pattern.

Why Is Cutting The Worst Case?Why Is Cutting The Worst Case?Why Is Cutting The Worst Case?Why Is Cutting The Worst Case?

►►Cutting melts Cutting melts ►►Cutt g e tsCutt g e tsand vaporizes and vaporizes more metal more metal faster thanfaster thanfaster than faster than welding.welding.

►► Paint, plating, Paint, plating, oil, or other oil, or other contamination contamination can be can be presentpresentpresent.present.

Poor ventilation is common during cuts. Poor ventilation is common during cuts.

Other dangers can overshadow fume safety.Other dangers can overshadow fume safety.

Thermal CuttingThermal Cutting -- Worst CasesWorst CasesThermal Cutting Thermal Cutting Worst CasesWorst Cases

►►Copper Brass and BronzeCopper Brass and Bronze►►Copper, Brass, and BronzeCopper, Brass, and Bronze►►Nickel alloys (Inconel, Monel)Nickel alloys (Inconel, Monel)

H df i llH df i ll►►Hardfacing alloysHardfacing alloys►►Stainless steelStainless steel►►Manganese wear steelManganese wear steel►►Painted or electroplated steelPainted or electroplated steel►►Painted or electroplated steelPainted or electroplated steel►►Galvanized steelGalvanized steel

Typical confined work area in hydro runner.Typical confined work area in hydro runner.

What Not To Test; What Not To Test; Low Risk Cutting JobsLow Risk Cutting JobsLow Risk Cutting JobsLow Risk Cutting Jobs

►►Bare carbon steelBare carbon steelM h i l tti hi iM h i l tti hi i►►Mechanical cutting or machiningMechanical cutting or machining

►►GrindingGrinding►►GrindingGrinding

NEXT HIGHEST FUME RISK:NEXT HIGHEST FUME RISK:CLADDING & CLADDING &

THERMAL SPRAYTHERMAL SPRAYW ldW ld l ddil ddi dd h df ih df i►►Weld Weld claddingcladding and and hardfacinghardfacing

►►ArcArc--SprayedSprayed coatingscoatings►►FlameFlame--SprayedSprayed coatingscoatings►►Commonly used inCommonly used in Fuel HandlingFuel Handling,, BoilersBoilers,,►►Commonly used in Commonly used in Fuel HandlingFuel Handling, , BoilersBoilers, ,

and and Hydro Rebuilds.Hydro Rebuilds.

EXAMPLE: CrEXAMPLE: Cr--6 RESULTS FOR6 RESULTS FORCLADDING AND THERMAL SPRAYCLADDING AND THERMAL SPRAYCLADDING AND THERMAL SPRAYCLADDING AND THERMAL SPRAY

►► Flame and Arc Spray in Boiler = Flame and Arc Spray in Boiler = 10 x PEL10 x PEL►► a e a d c Sp ay o ea e a d c Sp ay o e 00

►►Weld Cladding, Inconel 622, Boiler = Weld Cladding, Inconel 622, Boiler = 5 x PEL5 x PELg, ,g, ,

►►Weld Cladding 309 stainless, Hydro = Weld Cladding 309 stainless, Hydro = 5 x PEL5 x PEL

►►Compare to 309 stick weld = Compare to 309 stick weld = 1.5 x PEL1.5 x PEL

►►Other fumes follow similar pattern.Other fumes follow similar pattern.

Why Is Cladding & Spraying a Risk?Why Is Cladding & Spraying a Risk?Why Is Cladding & Spraying a Risk?Why Is Cladding & Spraying a Risk?

►► Large surfaceLarge surface►► Large surface Large surface areas covered areas covered very fast.very fast.

►►Usually applies Usually applies y ppy ppalloys high in alloys high in Cr, Ni, Mn, Cr, Ni, Mn,

d hd hand other and other heavy metals.heavy metals.

WHO TO TEST DURING CLADDING WHO TO TEST DURING CLADDING AND SPRAYING?AND SPRAYING?AND SPRAYING?AND SPRAYING?

►►Specialty contractors are usually well trainedSpecialty contractors are usually well trained►►Specialty contractors are usually well trained Specialty contractors are usually well trained in proper PPE. Check that they use it.in proper PPE. Check that they use it.

►►Other nearby workers Other nearby workers may notmay not be trained or be trained or h PPE I l d th i t t lh PPE I l d th i t t lhave proper PPE. Include them in test plan.have proper PPE. Include them in test plan.

►►Boundary testing and access controls often Boundary testing and access controls often used to limit incidental exposures.used to limit incidental exposures.pp

WELDING & BRAZINGWELDING & BRAZINGWELDING & BRAZING WELDING & BRAZING FUMESFUMESFUMESFUMES

►►Look for mostLook for most pounds used per hourpounds used per hour►►Look for most Look for most pounds used per hourpounds used per hour..►►Longest arcLongest arc--on times.on times.►►High risk alloys and Cr content.High risk alloys and Cr content.►►Worker head positionWorker head position►►Worker head position.Worker head position.►►Local ventilation.Local ventilation.

More Pounds Per Hour Means Higher More Pounds Per Hour Means Higher F R tF R tFume RatesFume Rates

►►Mechanized welding has Mechanized welding has longer run times thanlonger run times thanlonger run times than longer run times than manual.manual.

►► Fumes from multiple Fumes from multiple welders working in one welders working in one area will add up.area will add up.

HIGH RISK WELDING ALLOYSHIGH RISK WELDING ALLOYSHIGH RISK WELDING ALLOYSHIGH RISK WELDING ALLOYS

►►Nickel alloys (Inconel Monel)Nickel alloys (Inconel Monel)►►Nickel alloys (Inconel, Monel)Nickel alloys (Inconel, Monel)►►HardfacingHardfacing►►Stainless steelStainless steel►►Manganese wear steelManganese wear steel►►Manganese wear steelManganese wear steel►►Copper, Brass, and BronzeCopper, Brass, and Bronze

Low Cr vs High CrLow Cr vs High CrLow Cr vs High CrLow Cr vs High Cr

►►Tends to becomeTends to become►►Tends to become Tends to become a problem at a problem at 22--1/4% Cr and 1/4% Cr and higher.higher.

►►Usually not a Usually not a problem at problem at

/ % C d/ % C d11--1/4% Cr and 1/4% Cr and lower.lower.

Worker Head PositionWorker Head Positionk fk fBottom Worker of 2Bottom Worker of 2--man Teamman Team

Worker Head PositionWorker Head Positionk fk fTop Worker of 2Top Worker of 2--man Teamman Team

Typical Field Ventilation SystemTypical Field Ventilation System►►Bring in outside Bring in outside

air if possible.air if possible.pp

►►Removing heat is Removing heat is ggoften more often more valuable than valuable than removing fumes.removing fumes.

►►Move and adjust Move and adjust the system as job the system as job progresses.progresses.

Fresh Air Trunk for WelderFresh Air Trunk for Welder

Brazing FumesBrazing FumesBrazing FumesBrazing Fumes

►► Flux brazing Flux brazing ►► u b a gu b a gcreates more fume creates more fume than nonthan non--flux flux brazingbrazingbrazing.brazing.

►► Fluoride, bromide, Fluoride, bromide, or acid fumes areor acid fumes areor acid fumes are or acid fumes are possible with some possible with some types. types.

►►Don’t be afraid to Don’t be afraid to ask!ask!

Effect of Job DurationEffect of Job DurationEffect of Job DurationEffect of Job Duration

►►Most maintenance jobs are very shortMost maintenance jobs are very short►►Most maintenance jobs are very short Most maintenance jobs are very short duration. Fume exposure tends to be self duration. Fume exposure tends to be self limitinglimitinglimiting.limiting.

►►Fume exposure can Fume exposure can dramatically increase dramatically increase during longer duration jobsduring longer duration jobsduring longer duration jobs.during longer duration jobs.

►►Crews and management may not adjust PPE Crews and management may not adjust PPE d/ til ti di ld/ til ti di land/or ventilation accordingly.and/or ventilation accordingly.

WeldingWelding –– Higher Fume MethodsHigher Fume MethodsWelding Welding Higher Fume MethodsHigher Fume Methods

►►SelfSelf--shielded Flux Coreshielded Flux Core►►SelfSelf--shielded Flux Coreshielded Flux Core

►►GasGas--shielded Flux Coreshielded Flux Core

►►SMAW “stick electrode” over 1/8” SMAW “stick electrode” over 1/8” diameterdiameter

What Not To Test;What Not To Test;What Not To Test; What Not To Test; Low Risk Welding JobsLow Risk Welding Jobs

►►GTAW or “Tig”, except for ozone.GTAW or “Tig”, except for ozone.

►►SMAW “stick” on carbon steel withSMAW “stick” on carbon steel with►►SMAW stick on carbon steel with SMAW stick on carbon steel with short duration.short duration.

REVIEWREVIEW►► Look at Look at thermal cuttingthermal cutting first. That’s your highest first. That’s your highest

exposure potential.exposure potential.

►►CladdingCladding and and Thermal Spray Thermal Spray applications.applications.

►► Sort welding jobs by Sort welding jobs by processprocess and and alloyalloy; don’t ; don’t waste time testing low risk jobswaste time testing low risk jobswaste time testing low risk jobs.waste time testing low risk jobs.

►► Effect ofEffect of head positionhead position on test resultson test results►► Effect of Effect of head position head position on test results.on test results.

►► Effect ofEffect of local ventilationlocal ventilation on test resultson test results►► Effect of Effect of local ventilation local ventilation on test results.on test results.

Q S O S?Q S O S?QUESTIONS?QUESTIONS?