Welding Fumes v What Are Welding Fumes v

Welding Fumes v What Are Welding Fumes ? v Health Hazards v MSHA Regulations v Sampling Methods v Controls

Welding Fumes v What Are Welding Fumes ? v Health Hazards v MSHA Regulations v Sampling Methods v Controls

What Are Welding Fumes ? v. Welding Causes Solid Metal To Vaporize v. As Vaporized Metal Cools, It Condenses To Reform As Solid Particles - FUME v. Fumes Are Very Small Particles - Usually Much Smaller Than Dust Usually Larger Than 1 Micron l Fumes Can Be As Small As 1/1, 000 Micron l v. Unless Captured And Removed, Fumes Remain Suspended In Air Indefinitely

How Big Is A Micron ?

How Big Is A Micron ? Head of Pin 1/32 Inch

How Big Is A Micron ? 20 Microns Head of Pin 1/32 Inch

Size Comparison of Small Particles m Washed Foundry Sand 200 to 2, 000 Plant Spores 10. 0 to 40 Red Blood Cells 7 Cement Dust 1. 0 to 10 Bacteria 1/10 to 10 Tobacco Smoke 1/100 to 1/2 Metal Fumes 1/1, 000 to 1. 0

Composition of Welding Fumes v. Composition Varies Depending On: Material Being Welded l Welding Process, Rod, Electrode Type l Obtain MSDS From Manufacturer l v. Typical Welding Fume Constituents: Aluminum, Cadmium, Chromium, Iron, Moly l Cobalt, Copper, Zinc, Manganese, Tin, Lead l Nickel, Arsenic, Mercury, Vanadium, l Beryllium, Magnesium, Titanium, l v. May Be Metal or Oxide

Welding Fumes v What Are Welding Fumes ? v Health Hazards v MSHA Regulations v Sampling Methods v Controls

Exposure Primarily By Inhalation

Exposure Primarily By Inhalation Fumes Are 100% Respirable

Exposure Primarily By Inhalation Fumes Are 100% Respirable What Does “Respirable” Mean ?

Exposure Primarily By Inhalation Fumes Are 100% Respirable What Does “Respirable” Mean ?

Welding Fume Toxicity v. Acute Toxicity l Exposure To High Concentration Over Relatively Short Time l Symptoms Appear Relatively Quickly After Exposure v. Chronic Toxicity l Exposure To Lower Concentration Over Long Time (Months, Years) l Symptoms Appear Long After Initial Exposure

Welding Fume Toxicity Kidney Nervous Aluminum Beryllium Cadmium Chromium Cobalt Copper Iron Lead Manganese Nickel Zinc Liver GI X X X X X Lung X X X X X

Welding Fume Toxicity v. Exposure Usually Involves More Than One Metal l Toxic Effects May Be Additive v. Examples l Blood - Manganese and Lead l CNS - Manganese and Lead l Kidney - Lead and Cadmium l Respiratory System - Magnesium, Manganese, Copper, and Zinc

Welding Fume Toxicity v. Metal Fume Fever l Symptoms Are Fever, Chills, Shaking l Symptoms Appear 4 -12 Hrs After Exp. l Recovery Usually Within 1 Day l Usually Associated With Brief High Inhalation Exposure To Zinc, But Magnesium & Copper Also May Cause l Daily Exposure May Confer Immunity l Symptoms May Return If Exposure Interrupted (3 -Day Weekend)

Welding Fume Toxicity v. Welding Fumes Can Cause Cancer Arsenic (Lung, Lymphatic) l Beryllium (Lung) l Cadmium (Prostatic and Lung) l Chromium (Lung) l Nickel (Lung) l v. Welders May Also Be Exposed To: Silica, Asbestos, Ozone l Thermal Decomposition of Paint, Flux, Electrode Coatings (CO, CO 2, NO 2, HCN, COCl 2, Fluoride Gases, Smoke, Etc. ) l

Welding Fumes v What Are Welding Fumes ? v Health Hazards v MSHA Regulations v Sampling Methods v Controls

MSHA Regulations § 56/57. 5001 Establishes Exposure Limits For Airborne Contaminants l TWA 8 And Ceiling Limits Listed In 1973 ACGIH Booklet of Threshold Limit Values (TLV’s) u. TWA 8 Time Weighted Average For 8 Hrs u. Ceiling Limits Cannot Be Exceeded For Any Length Of Time l ACGIH 1973 TLV Booklet References 1968 “PA Rules” For Short Term Limits

Exposure Limits For Common Welding Fumes TWA 8 Beryllium Short Term 2. 0 g/m 3 25. 0 g/m 3 Magnesium Oxide 10. 0 mg/m 3 Vanadium 50. 0 g/m 3 Chromium 1. 0 mg/m 3 Manganese (C) 5. 0 mg/m 3 Nickel 1. 0 mg/m 3 Cobalt 100. 0 g/m 3 20. 0 mg/m 3 50. 0 g/m 3 3. 0 mg/m 3 5. 0 mg/m 3 3. 0 mg/m 3 500. 0 g/m 3 3 3

Milligrams or Micrograms Per Cubic Meter of Air mg 1 meter or g 1 meter 1 milligram = 1/1, 000 gram = 35/1, 000 oz 1 microgram = 1/1, 000 gram = 35/1, 000, 000 oz

How Much is 100 3 g/m ? 100 g/m 3 = 0. 1 ounce per 1, 000 ft 3

MSHA Regulations § 56/57. 5002 Dust, Gas, Mist, And Fume Surveys Shall Be Conducted As Frequently As Necessary To Determine The Adequacy Of Control Measures § 56/57. 5005 Control of Harmful Airborne Contaminants Shall Be, Insofar As Feasible, By Engineering Controls l Respirators Permitted Under Certain Circumstances

MSHA Regulations Part 46 and Part 48 Training § 56/57. 14213(b) All Welding Operations Shall Be Well Ventilated § 56/57. 20011 Areas Where Health or Safety Hazards Exist That Are Not Immediately Obvious Shall Be Barricaded Or Warning Signs Posted

Welding Fumes v What Are Welding Fumes ? v Health Hazards v MSHA Regulations v Sampling Methods v Controls

Sampling Methods v. For Compliance With § 56/57. 5001 And § 56/57. 5002 v. Full Shift Or Short Term

Sampling Methods v. For Compliance With § 56/57. 5001 And § 56/57. 5002 v. Full Shift Or Short Term v. Sample Pump, Pump Calibrator, Filters

Sampling Methods v. For Compliance With § 56/57. 5001 And § 56/57. 5002 v. Full Shift Or Short Term v. Sample Pump, Pump Calibrator, Filters v. Place Filter In Breathing Zone Under Hood

Sampling Methods v. For Compliance With § 56/57. 5001 And § 56/57. 5002 v. Full Shift Or Short Term v. Sample Pump, Pump Calibrator, Filters v. Place Filter In Breathing Zone Under Hood v. Pump Draws Air Over Filter; Contaminants Captured On Filter

Sampling Methods v. Analytic Lab Determines Weights Of Individual Contaminants On Filter v. Weights Converted To Concentrations

Sampling Methods v. Analytic Lab Determines Weights Of Individual Contaminants On Filter v. Weights Converted To Concentrations weight of contaminant volume of air

Sampling Methods v. Analytic Lab Determines Weights Of Individual Contaminants On Filter v. Weights Converted To Concentrations weight of contaminant volume of air mg or g m 3

Sampling Methods v. Analytic Lab Determines Weights Of Individual Contaminants On Filter v. Weights Converted To Concentrations weight of contaminant volume of air mg or g m 3 v. Measured Concentration Compared To Established Exposure Limit

Sampling Methods v. Analytic Lab Determines Weights Of Individual Contaminants On Filter v. Weights Converted To Concentrations weight of contaminant volume of air mg or g m 3 v. Measured Concentration Compared To Established Exposure Limit l Measured Less Than Limit - - No Action Req’d

Sampling Methods v. Analytic Lab Determines Weights Of Individual Contaminants On Filter v. Weights Converted To Concentrations weight of contaminant volume of air mg or g m 3 v. Measured Concentration Compared To Established Exposure Limit Measured Less Than Limit - - No Action Req’d l Measured Over Limit - - Implement Controls l

Welding Fumes v What Are Welding Fumes ? v Health Hazards v MSHA Regulations v Sampling Methods v Controls

Controls (§ 56/57. 5005) v. Feasible Engineering Controls v. Personal Protective Equipment (PPE) l PPE Allowed As Means Of Compliance Only In Limited Situations u. Where Feasible Engineering Controls Do Not Exist u. While Installing Engr. Controls u. Occasional Entry Into Hazardous Atmosphere For Maintenance

Engineering Controls v. General Ventilation l Natural or Mechanically Induced (Fans) Airflow Over Work Area That Dilutes and Carries Away Contaminants v. Local Exhaust Ventilation l Captures and Removes Airborne Contaminants Before They Escape Into Workplace Air l Local Exhaust Always Preferred For Toxic Airborne Contaminants

General Ventilation v. Outdoors - Wind v. Indoors Open Shop Doors/Windows l What Blows In, Must Blow Out l v. Fans Fixed - Roof, Walls, Windows l Portable l Blow Fresh Air Into Work Area, But Don’t Blow Fumes Into Welder’s Breathing Zone l Push-Pull Fan Arrangements l Need Provision For “Make Up” Air l

Local Exhaust Ventilation v. Capture Hood & Fixed Duct System

Local Exhaust Ventilation v. Portable “Fume Eliminator”

Local Exhaust Ventilation v. Down Draft Table

Local Exhaust Ventilation v. System Must Have Adequate Air Velocity To Draw In Fume Particles l Minimum Capture Velocity 100 ft/min l Better To Design For 200 ft/min v. May Need Provision For “Make Up” Air l 10” Round Duct Drawing 200 ft/min l Air Volume Removed From Work Area Is 110 cfm

Local Exhaust Ventilation v. Must Position Hood Correctly l Air Velocity Drops Rapidly With Distance Away From Hood Opening

Local Exhaust Ventilation v. Must Position Hood Correctly l Air Velocity Drops Rapidly With Distance Away From Hood Opening 10 inches Airflow 10 “ 200 120 60 15 Air Velocity (ft/min)

Respiratory Protection v. Air Purifying Or Supplied Air l May Be Integral With Welding Hood v. Respirator Use Must Include Implementation of Respiratory Protection Program (See ANSI Z 88. 2 -1969) Written Procedures on Selection and Use l Respirator Training and Fit Testing l Respirator Inspection, Cleaning, Storage l Workplace Surveillance l Medical Evaluation Recommended l

Welder’s Powered Air Purifying Respirator Half-Mask Cartridge (PAPR) Respirator Supplied-Air Respirator

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