Welding Fumes (Long)
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Transcript of Welding Fumes (Long)
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Welding Fumes
What Are Welding Fumes ?
Health Hazards MSHA Regulations
Sampling Methods Controls
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Welding Fumes
What Are Welding Fumes ?
Health Hazards MSHA Regulations
Sampling Methods Controls
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What Are Welding Fumes ?
Welding Causes Solid Metal To VaporizeAs Vaporized Metal Cools, It Condenses
To Reform As Solid Particles - FUME
Fumes Are Very Small Particles - -Usually Much Smaller Than Dust
Dust Usually Larger Than 1 Micron
Fumes Can Be As Small As 1/1,000 MicronUnless Captured And Removed, Fumes
Remain Suspended In Air Indefinitely
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How Big Is A Micron ?
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How Big Is A Micron ?
Head of Pin
1/32 Inch
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How Big Is A Micron ?
Head of Pin20 Microns
1/32 Inch
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Size Comparison of Small Particles
mWashed Foundry Sand 200 to2,000
Plant Spores 10.0 to40Red Blood Cells 7
Cement Dust 1.0 to10
Bacteria 1/10 to10
Tobacco Smoke 1/100 to1/2
Metal Fumes 1/1,000 to1.0
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Composition of Welding Fumes
Composition Varies Depending On: Material Being Welded
Welding Process, Rod, Electrode Type
Obtain MSDS From Manufacturer
Typical Welding Fume Constituents:
Aluminum, Cadmium, Chromium, Iron, Moly
Cobalt, Copper, Zinc, Manganese, Tin, Lead
Nickel, Arsenic, Mercury, Vanadium,
Beryllium, Magnesium, Titanium,
May Be Metal or Oxide
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Welding Fumes
What Are Welding Fumes ?
Health HazardsMSHA Regulations
Sampling Methods Controls
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Exposure Primarily By Inhalation
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Exposure Primarily By Inhalation
Fumes Are 100% Respirable
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Exposure Primarily By Inhalation
Fumes Are 100% Respirable
What Does Respirable Mean ?
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Exposure Primarily By Inhalation
Fumes Are 100% Respirable
What Does Respirable Mean ?
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Welding Fume Toxicity
Acute Toxicity
Exposure To High Concentration Over
Relatively Short Time
Symptoms Appear Relatively Quickly
After Exposure
Chronic Toxicity
Exposure To Lower ConcentrationOver Long Time (Months, Years)
Symptoms Appear Long After Initial
Exposure
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Welding Fume Toxicity
Kidney Nervous Liver GI Lung
Aluminum X X
Beryllium X
Cadmium X X X X
Chromium X X X XCobalt X X X
Copper X X
Iron X X X X
Lead X X X
Manganese X X
Nickel X X
Zinc X X
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Welding Fume Toxicity
Exposure Usually Involves MoreThan One Metal
Toxic Effects May Be Addi t ive
ExamplesBlood - Manganese and Lead
CNS - Manganese and Lead
Kidney - Lead and Cadmium
Respiratory System - Magnesium,
Manganese, Copper, and Zinc
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Welding Fume Toxicity
Metal Fume Fever
Symptoms Are Fever, Chills, Shaking
Symptoms Appear 4-12 Hrs After Exp.
Recovery Usually Within 1 DayUsually Associated With Brief High
Inhalation Exposure To Zinc, But
Magnesium & Copper Also May CauseDaily Exposure May Confer Immunity
Symptoms May Return If Exposure
Interrupted (3-Day Weekend)
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Welding Fume Toxicity
Welding Fumes Can Cause Cancer
Arsenic (Lung, Lymphatic) Beryllium (Lung)
Cadmium (Prostatic and Lung)
Chromium (Lung) Nickel (Lung)
Welders May Also Be Exposed To:
Silica, Asbestos, Ozone Thermal Decomposition of Paint, Flux,
Electrode Coatings (CO, CO2, NO, NO2, HCN,
COCl2, Fluoride Gases, Smoke, Etc.)
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Welding Fumes
What Are Welding Fumes ?
Health HazardsMSHA Regulations
Sampling MethodsControls
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MSHA Regulations
56/57.5001Establishes ExposureLimits For Airborne Contaminants
TWA8 And Ceiling Limits Listed In
1973 ACGIH Booklet of ThresholdLimit Values (TLVs)
TWA8 Time Weighted Average For 8 Hrs
Ceiling Limits Cannot Be Exceeded ForAny Length Of Time
ACGIH 1973 TLV Booklet References
1968 PA Rules For Short Term Limits
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Exposure Limits For Common
Welding FumesTWA8 Short Term
Beryllium 2.0g/m3 25.0g/m3
Magnesium Oxide 10.0 mg/m3 20.0 mg/m3
Vanadium 50.0g/m3 50.0g/m3
Chromium 1.0 mg/m3
3.0 mg/m3
Manganese (C) 5.0 mg/m3 5.0 mg/m3
Nickel 1.0 mg/m3 3.0 mg/m3
Cobalt 100.0 g/m3 500.0g/m33 3
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Milligrams or Micrograms
Per Cubic Meter of Air
1 meter
1 meter
mgor
g 1 meter
1 milligram = 1/1,000 gram = 35/1,000,000 oz
1 microgram = 1/1,000,000 gram = 35/1,000,000,000 oz
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How Much is 100g/m3 ?
100g/m3 = 0.1 ounce per 1,000,000 ft3
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MSHA Regulations
56/57.5002Dust, Gas, Mist, And FumeSurveys Shall Be Conducted As
Frequently As Necessary To Determine
The Adequacy Of Control Measures
56/57.5005Control of Harmful Airborne
Contaminants Shall Be, Insofar AsFeasible, By Engineering Controls
Respirators Permitted Under Certain
Circumstances
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MSHA Regulations
Part 46 and Part 48 Train ing
56/57.14213(b) All Welding
Operations Shall Be Well Ventilated56/57.20011 Areas Where Health
or Safety Hazards Exist That Are
Not Immediately Obvious Shall Be
Barricaded Or Warning Signs
Posted
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Welding Fumes
What Are Welding Fumes ?
Health Hazards MSHA Regulations
Sampling MethodsControls
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Sampling Methods
For Compliance With 56/57.5001And
56/57.5002
Full Shift Or Short Term
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Sampling Methods
For Compliance With 56/57.5001And
56/57.5002
Full Shift Or Short Term
Sample Pump, Pump Calibrator, Filters
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Sampling Methods
For Compliance With 56/57.5001And
56/57.5002
Full Shift Or Short Term
Sample Pump, Pump Calibrator, Filters
Place Filter In Breathing Zone Under
Hood
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Sampling Methods
For Compliance With 56/57.5001And
56/57.5002
Full Shift Or Short Term
Sample Pump, Pump Calibrator, Filters
Place Filter In Breathing Zone Under
Hood
Pump Draws Air Over Filter;
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Sampling Methods
Analytic Lab Determines Weights OfIndividual Contaminants On Filter
Weights Converted To Concentrations
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Sampling Methods
Analytic Lab Determines Weights OfIndividual Contaminants On Filter
Weights Converted To Concentrations
weight of contaminant
volume of air
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Sampling Methods
Analytic Lab Determines Weights OfIndividual Contaminants On Filter
Weights Converted To Concentrations
weight of contaminant mg orgvolume of air m3
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Sampling Methods
Analytic Lab Determines Weights OfIndividual Contaminants On Filter
Weights Converted To Concentrations
weight of contaminant mg orgvolume of air m3
Measured Concentration Compared ToEstablished Exposure Limit
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Sampling Methods
Analytic Lab Determines Weights OfIndividual Contaminants On Filter
Weights Converted To Concentrations
weight of contaminant mg orgvolume of air m3
Measured Concentration Compared ToEstablished Exposure Limit
Measured Less Than Limit - - No Action Reqd
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Sampling Methods
Analytic Lab Determines Weights OfIndividual Contaminants On Filter
Weights Converted To Concentrations
weight of contaminant mg orgvolume of air m3
Measured Concentration Compared ToEstablished Exposure Limit
Measured Less Than Limit - - No Action Reqd
Measured Over Limit - - Implement Controls
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Welding Fumes
What Are Welding Fumes ?
Health Hazards MSHA Regulations
Sampling Methods Controls
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Controls (56/57.5005)
Feasible Engineering Controls
Personal Protective Equipment (PPE)
PPE Allowed As Means Of Compl iance
Only In Limited Situations
Where Feasible Engineering Controls
Do Not Exist
While Installing Engr. Controls
Occasional Entry Into Hazardous
Atmosphere For Maintenance
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Engineering Controls
General VentilationNatural or Mechanically Induced (Fans)
Airflow Over Work Area That Dilutes
and Carries Away ContaminantsLocal Exhaust Ventilation
Captures and Removes Airborne
Contaminants Before They Escape IntoWorkplace Air
Local Exhaust Always Preferred For
Toxic Airborne Contaminants
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General VentilationOutdoors - Wind
Indoors
Open Shop Doors/Windows
What Blows In, Must Blow Out
Fans
Fixed - Roof, Walls, Windows
Portable
Blow Fresh Air Into Work Area, But Dont Blow
Fumes Into Welders Breathing Zone
Push-Pull Fan Arrangements
Need Provision For Make Up Air
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Local Exhaust Ventilation
Capture Hood & Fixed Duct System
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Local Exhaust Ventilation
Portable Fume Eliminator
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Local Exhaust Ventilation
Down Draft Table
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Local Exhaust Ventilation
System Must Have Adequate AirVelocity To Draw In Fume Particles
Minimum Capture Velocity 100 ft/min
Better To Design For 200 ft/minMay Need Provision For Make Up Air
10 Round Duct Drawing 200 ft/min
Air Volume Removed From Work Area
Is 110 cfm
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Local Exhaust Ventilation
Must Position Hood Correctly Air Velocity Drops Rapidly With Distance
Away From Hood Opening
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Local Exhaust Ventilation
Must Position Hood Correctly Air Velocity Drops Rapidly With Distance
Away From Hood Opening
10200 120 60 15
10 inches
Air Velocity (ft/min)
Hood Opening
Airflow
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Respiratory Protection
Air Purifying Or Supplied Air
May Be Integral With Welding Hood
Respirator Use Must Include
Implementation of Respiratory Protection
Program (See ANSI Z88.2-1969)
Written Procedures on Selection and Use
Respirator Training and Fit Testing
Respirator Inspection, Cleaning, Storage
Workplace Surveillance
Medical Evaluation Recommended
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Welders Powered
Air Purifying
Respirator(PAPR) Half-Mask CartridgeRespirator Supplied-AirRespirator
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Thank You