Brazing and welding generate fumes that can be toxic to breathe. Welders and people working in the same space must protect themselves with general specific devices, as well as adapted individual protection.
What are the dangers of welding fumes?
The soldering iron generates high temperatures in order to reach the melting point of the materials to be soldered (for welding) or of the filler metal (for brazing). It is at this point that fumes are formed which mix with the ambient air. The particles contained in these fumes are microscopic, allowing them to enter the respiratory system, reaching the pulmonary alveoli, located deep in the lungs at the ends of the bronchioles.
If inhaled repeatedly over time, the fumes can trigger lung disease, but can also attack the central nervous system or kidneys. The conditions manifest themselves as acute attacks and/or chronic diseases.
The most frequent pathologies are as follows: asthma, pulmonary oedema, chronic bronchitis, metal fume fever, toxic pneumonia, kidney dysfunction, etc.
How to prevent risks related to welding
The fumes emitted during welding depend on the raw materials used, the brazing process, the gas, contaminants (various types of dirt on the metal), the coating of metals, etc. Less than 5% of the fumes are produced by the welded or brazed metal, while the rest (95%) come from the environment.
To prevent risks, it is therefore necessary to work on the whole and not focus only on the action of the soldering iron.
The welder’s environment
The first precaution to take is the space in which the welder and his colleagues work. When the space is confined, it is imperative to create an evacuation of toxic fumes. This prevents them from being inhaled, but also from risking anoxic-asphyxia, which corresponds to the oxygen depletion of the atmosphere.
In addition to general ventilation devices – which are often expensive to install – there are more efficient and less expensive local exhaust ventilation processes. The various devices can be adapted according to the type of welding or brazing being performed: table, torch or extractor hood, welding booth, etc. For maximum efficiency, it is ideal to combine general and localized ventilation.
Parts must be cleaned and degreased before welding to reduce fumes. The room must always be kept clean to avoid dust being stirred into the atmosphere by the movement between the hot air released by the soldering iron and metals and the cooler ambient air.
The choice of soldering iron and the technique used
The brazing and welding processes are diverse. While the most suitable one should be selected according to the work to be carried out, the choice of technology must also take into account the fumes. Some modern appliances produce fewer emissions: e.g. friction stir welding or submerged arc welding.
Newer welding machines use a less polluting technology of pulsed or synergic soldering machines. It is also advisable to reduce carbon dioxide consumption by choosing a more suitable shielding gas.
Individual protection
Ventilation devices are used to protect people sharing the welder’s environment, but the welder can also be equipped with an individual device.
The breathing apparatus allows direct filtration of the fumes. The filters are selected according to the materials used and the working time. They must be cleaned and changed regularly to maintain their effectiveness.
It is also important to protect the welder’s eyes, which can be damaged by radiation.