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Basics of Welding Explained

Manufacturing is a key part of the UK's economy and contributed 11% of GVA back in 2019. The industry employs over 2.7 million people in the UK alone and it's fair to say that many of these businesses undertake welding of some kind in their workplaces. Whether welding is used to produce products or used to maintain machinery, the process is one of the most widely across many industries.

But why is welding fume so topical at the moment? To answer your questions, we have put together a series of articles that will help you understand welding fume a little better, which will ultimately lead you towards being able to control it in your workplace.

What is Welding and What are the Common Methods of Welding Applications?

Many may be unfamiliar with welding or have little experience dealing with variants in welding techniques. Therefore, it's good to know more about each welding process as a starting point. Listed below are the general methods and techniques used for welding.

Metal Inert Gas (MIG)

An arc welding process where a wire electrode is fed through a welding gun and into the weld pool, joining two materials together. Usually, Argon and Carbon Dioxide gases are used to shield the weld, which is sent through the welding gun.

Tungsten Inert Gas (TIG)

Tungsten Inert Gas Welding, also known as Gas tungsten arc welding (GTAW), is an arc welding process that uses a non-consumable tungsten electrode to produce the weld. The weld area and electrode is protected from oxidation or other atmospheric contamination by an inert shielding gas usually Argon or helium, and a filler metal is fed into the weld pool.

Shielded Metal Arc Welding (SMAW)

Shielded metal arc welding (SMAW), also known as manual metal arc welding (MMA or MMAW), flux shielded arc welding or informally as stick welding, is a manual arc welding process that uses a consumable electrode covered with a flux to lay the weld.

Submerged Arc Welding (SAW)

Submerged-arc welding (SAW) is an arc welding process which involves generating an arc between a continuously fed electrode and the workpiece, which then melts the material and allows for the filler to join the materials together forming a weld. A blanket of powdered flux generates a protective gas shield which protects the weld zone. The flux solidifies and is then scraped away from the weld itself.

Metal Arc Gouging and Cutting

Metal arc gouging also referred to as air carbon arc cutting is an arc cutting process where metal is cut and melted by the heat of a carbon arc. A jet of air, which forces the molten metal away from the workpiece, is used to remove a pre-existing weld. It involves using a consumable carbon or graphite electrode to melt the material, which is then blown away by an air jet.

Further exposures to metal fumes are likely during metal cutting processes where plasma or gas burning is used.

Welding Fume Explained

What is Welding Fume and why is it a significant workplace hazard?

Mixed particulate and gases are emitted by welding. The gas and particulate emission is dependant on the materials welded, or the materials used to weld the metals together as fillers or fluxes. These can be inhaled and settle deep within the lungs causing both chronic and acute effects on health.

Common materials often welded are:

  • Mild Steel

  • High Nickel Alloy

  • Stainless Steel

  • Galvanised Steel

The consumables often used, contain various metal fillers and fluxes. Which, individually pose a risk to health depending on what constituents are included in the products. Essentially, these form part of the overall fume.

The HSE's Standpoint

The Health and Safety Executive are currently focusing on businesses who utilise welding within their workplaces and enforcing against non-compliance with the COSHH Regulations. Rightly so as recent research has found welding fume to be carcinogenic. This is further to the known effects the likes of manganese and nickel have on the central nervous system, just one of many examples of how specific metal fumes can have a negative impact on target organs.

Back in February 2019, the Health and Safety Executive (HSE) published the document STSU1 2019 titled: Changes in Enforcement Expectations for Mild Steel Welding Fume. In this bulletin it is outlined that there has been new scientific evidence from the International Agency for Research on Cancer (IARC) that exposure to mild steel welding fume can cause lung cancer and possibly kidney cancer in humans and, as such, has been reclassified as Category 1: Carcinogenic to Humans.

Under this reclassification, the HSE have noted that regardless of duration, they will no longer accept any welding to be undertaken without any suitable exposure control measures in place. This is due to there being no known level of safe exposure.

Finding Out More About Carcinogenic Substances and Why COSHH is Important

Want to learn more about common Carcinogenic Substances? Why not take a look at our past articles written on the run-up to world cancer day. Check them out below.

Introducing Wood Processing

Diesel Engine Exhaust Emissions Awareness

Styrene Exposure Linked with Occupational Cancer

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