Welding and hot cutting processes do not usually generate harmful levels of vibration however there may be a risk from some associated tasks like grinding, needle scaling. For further information and HSE’s ‘vibration exposure calculator’ go to the HSE hand arm vibration pages.
With the exception of TIG, electric arc welding generates harmful levels of noise. The process itself produces noise, the other tasks that a welder will typically do are also noisy, and welding is generally carried out in a noisy environment. Noise levels experienced during arc welding and cutting vary with the process. A list of typical noise levels for different types of welding process and associated tasks is given below.
|Process||Typical noise levels|
|TIG||up to 75 dB(A)|
|MMA||85 - 95 dB(A)|
|MIG||95 – 102 dB(A)|
(hand-held up to 100A, cutting up to 25mm thickness only)
|98 – 105 dB(A)|
|Flame gouging||95 dB(A)|
|Flame cutting||up to 100 dB(A)
(typically above 90 dB(A) when cutting thicknesses above 40 mm)
|Air arc gouging||100 – 115 dB(A)|
|Grinding||95 – 105 dB(A)|
The actual noise levels will depend on several factors. For instance, noise is likely to increase with increasing consumable diameter and with increasing current. Also, the type of metal being worked will have an effect, stainless steel tending to produce higher noise levels than mild steel.
Where cutting is concerned, the thickness of material being cut will affect the noise produced, thicker materials being noisier.
For the loudest processes (plasma cutting and air arc gouging) the dominant source of noise is the high-pressure compressed air. The design of air nozzle can have a big effect on noise emission and some companies may offer ‘reduced noise’ equipment.
Daily personal noise exposure depends both on the level of noise (the dB(A) value) and the time of exposure during a working day. When assessing potential noise exposure an important consideration is how long welding operations last. For welding and hot cutting processes, noise is only generated when an arc is struck or flame lit. A production welder’s ‘arcing’ time may be as much as 80%of the shift whereas a fabricator welder may spend most of the day setting the job up before starting any welding. Obviously sometimes setting up can be fairly quiet eg marking out other times it can be quite noisy, edge preparation by manual grinding.
In addition welders frequently work in noisy environments and carry out other noisy operations such as needle scaling and grinding. It is likely that a welder’s individual noise exposure will be affected not only by their own work, but also by the work of their colleagues.
You should consider these factors when assessing noise risk. Under-estimating noise risk could lead to damaged hearing however over-estimating noise exposure could lead to unnecessary expense or overprotection.
The best option will be to eliminate the noisy process, perhaps by buying in the material cut to size by the supplier. However welding and hot cutting is often the only practical method so the main focus should be on practical methods to reduce noise levels for the given process and managing the residual risk using ear plugs, ear muffs or other hearing protection.
An example of this would be moving from hand-held plasma cutting to an automated submerged plasma cutter. This can result in noise levels below 80 dB(A). Water shrouded plasma cutters are available and may be practical for some operations. Submerged or water shrouded systems reduce fume emission as well as noise.. Obviously with any consideration of alternative ways of working, the practicality of the alternative and investment required must be weighed against the benefits (health, safety, productivity, etc.) that may arise.
Welding booths can be useful in preventing the noise from a welder affecting others in the workshop. Consider a welding booth with 3 solid walls. The addition of 75 mm thick mineral wool or fibre glass absorbent lining on the inside of the booth could give 5 dB reduction in noise level inside the booth. To prevent damage to the absorbent material it can be covered with thin perforated sheet steel with at least 30% open area.
Remember that the dB(A) scale is logarithmic, so although a reduction of 5dB(A) does not sound that much it is actually a large reduction in sound power.
Hearing protection should be selected based on four criteria; ability to reduce the noise exposure, compatibility with other items of PPE (such as welding masks, safety helmets, etc.), comfort, and suitability for the working environment and activity.
For compatibility with welding masks, options include ear plugs and slim-line ear muffs with a neckband rather than a head band.
If, as may be the case with some welding activities, hearing protection is being relied on as the main solution to reducing noise exposure, it is vital that correct training in its use is given. The importance of wearing the protection for all the time spent in a noisy area, or engaged in a noisy activity, must be emphasised. Failure to wear hearing protection for even a small amount of the time exposed to noise can affect significantly the effectiveness of the hearing protection device in reducing daily noise exposure.
See the HSE noise webpage for further information on issuing hearing protection