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Is there a problem of fume in resistance spot welding?


Frequently Asked Questions

Resistance spot welding is a relatively low heat-input process but there are sources of fume to be considered.

Metal coatings (predominantly zinc), lubricants and adhesives or sealants are sources of fume. Zinc fume is formed in very small quantities and the metal itself is not particularly hazardous. General ventilation is usually sufficient to keep the fume well below allowable levels but it is usual to provide local extraction in manual operations where concentration of fume in the breathing zone may be higher.

The majority of emissions in resistance welding are probably oil vapour or its breakdown products produced when welding oily steel. A range of products is used for corrosion protection and lubrication for press forming. There may be hazardous organic compounds in very small quantities, so the same approach described above for zinc should be appropriate.

When welding through adhesives and sealants, very little fume is produced unless hot conditions are used or, more particularly, if weld splash is produced. As with all organic materials, the breakdown products of the locally burnt adhesive or sealant may contain a small quantity of compounds, which should be controlled to a low level. Again, good general ventilation and possibly local extraction should be sufficient to ensure that breathing zone fume levels are reduced to safe levels.

The risk of fume will depend on the particular application, manufacturing method and proximity of staff to the source of the fume. Refer to local Health and Safety Executive to ensure compliance with regulations. In some cases, fume measurements may need to be made.

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