WELDING

WHAT FACTORS DETERMINE THE COMPOSITION OF WELDING FUME

TYPE OF WELDING

FLUX/ELECTRODE/CONSUMABLE

SURFACE COATING

PARENT MATERIAL

MOST IMPORTANT ASPECT OF OF WELDING THAT DETERMINES THE EXPOSURE LIMIT TO BE SET

COMPOSITION OF THE FUME

WHAT PERCENTAGE OF FUME COMPOSITION IS MADE UP BY CONSUMABLES IN ARC WELDING?

90% OF THE FUME COMPOSITION IN ARC WELDING IS FROM THE ELECTRODE OR CONSUMABLE. PARENT MATERIAL IS A MINOR CONTRIBUTOR

MAIN FACTOR CONTRIBUTING TO FUME COMPOSITION IN ARC WELDING

CONSUMABLE

1. MMA/SMAW/FCAW VS 2. MIG/MAG/GMAW

1. FUME COMPOSED MAINLY OF FLUX AND ELECTRODE AND MUCH MORE HEXAVELENT CHROMIUM WILL BE PRESENT IN FUME NECESSATING MUCH LOWER EXPOSURE LIMITS I.E. HEXAVALENT CHROMIUM SHOULD BE AS LOW AS REASONABLY PRACTICABLE

SURFACE COATINGS SUCH AS ZINC AND PAINT SHOULD BE REMOVED BEFORE WELDING AS A PRECAUTION EVEN IF SDS SHEETS ARE AVAILABLE

TRUE

The most important factor influencing the quantity of fume

the welding process(OPEN ARC) e.g. MMA/MIG MUCH HIGHER vs TIG/GTAW

WELDING PARAMETERS SUCH A CURRENT AND VOLTAGE AND METAL REMOVAL RATES THROUGH CUTTING AND GOUGING CONTRIBUTE BUT MINOR ROLE

LOWER DUTY CYCLE

SHORTER EXPOSURES DURATION

LARGE WELL VENTILATED SPACES

ARE PROTECTIVE

TRUE

WELDING POSITION WITH HIGHEST LEVEL OF EXPOSURE

ABOVE THE PLUME IS EVEN WORSE THAN IN CLOSE PROXIMITY

WHAT ARE THE COMPONENTS OF A WELDING EXPOSURE ASSESSMENT

FUME COMPOSITION

FUME QUANTITY

WELDING PROCESS AND PARAMETERS

WELDING POSITION

ENVIRONMENT(CONFINED SPACES)

DUTY CYCLE AND DURATION OF EXPOSURE

PPE

MEASURMENTS OF PARTICULATE FUME

AIR SAMPLING

PERSONAL SAMPLING BEHIND HELMET - PERSONAL EXPOSURE

FIXED POINT SAMPLING - OTHER AREAS, OTHER WORKERS AND FAILURE OF CONTROL MEASURES

BASED ON REGULATIONS. KEEP RECORDS FOR 40 YEARS AND 5 YEARS IN ALL OTHER CASES

WELDING FUME CONTROL

LOCAL EXTRACTION VENTILATION WITH A MANAGEMENT SYSTEM IS THE MAIN METHOD

SUBSTITUTION OR ELIMINATION NOT ALWAYS POSSIBLE

GENERAL VENTILATION DOES NOT PROTECT THE WELDER

PPE - LAST RESORT AND IN ADDITION TO OTHER CONTROLS

TYPES OF RPE

RESPIRATORS - DISPOSABLE OR FACE MASK WITH FILTERS

AIR SUPPLIED- AIR SOURCE IS SEPARATE

TYPES OF LEV

MOBILE EXTRACTION HOODS

BENCHES, BOOTHS OR ON THE GUN ITSELF

INFORMATION INSTRUCTION AND TRAINING

EXPLAIN:

HEALTH HAZARDS AND RISKS

PROVIDE THE SDS SHEETS!

AIR MONITORING ESPECIALLY FOR MEL SUBSTANCES AND MEDICAL SURVEILLANCE

WHAT, WHY, HOW AND IMPORTANCE, CONSEQUENCES

INSTRUCT ON CONTROL MEASURES - HOW AND WHY INCLUDING PPE AND ALSO HOW TO ACCESS RESULTS

EMERGENCIES, DISPOSAL,STORAGE, PRECAUTIONS

ETHICS- MAINTAIN CONFIDENTIALITY OF INDIVIDUAL RECORDS BUT ALLOW ACCESS TO GROUP RECORDS OR SURVEILLANCE AND AIR MONITORING

Ozone

Mig + argon + Aluminium silicon highest generation + high voltage,

Manual Metal Arc Welding (also known as SMAW)

Stick welding

Simple

Electricity, electric arc, consumable used up. Joining of molten metal. Flux forms a protective shield gas. Slag protects the weld during cooling.

External shielding gas in mig

Argon and CO2

Mig vs MMA

Continuous electrode supply via spool

External supply of shielding gas

Less slag and clean welds. Less cleanup

Stick welding flux produces the shield and more splatter and creates slag, requiring clean up