Brazing Alloys and Fluxes
Brazing is a reliable, simple and safe method of joining metal components. However, brazing alloys and fluxes contain elements, which, if overheated, produce fumes, which may be harmful or dangerous to health. Special care should be taken not to overheat cadmium containing brazing alloys, as inhalation of cadmium oxide fume can be particularly harmful.
Brazing should be carried out in a well-ventilated area with operators positioned so that any fume generated will not be inhaled. The installation of local extraction is being increasingly recommended, particularly when brazing with cadmium containing alloys.
Apart from fume hazards, flux can be moderately irritating to the skin and prolonged contact should be avoided.
It must be said, however, that with correct brazing practice and adequate ventilation the Health and Safety risks are minimal.
Many of the recommendations in this data sheet are common sense, It is important that management, safety officers and individual brazing operators make themselves fully conversant with all of these safety precautions and so minimise the chance of accidents occurring.
The most versatile brazing alloys are those based on the silver-copper-cadmium-zinc or silver-copper-zinc systems. They are all distinguished by their low melting points and good flow properties. They should never be overheated. Overheating is bad brazing practice and is likely to result in poor joints and increased evolution of fume. Metal and metal oxide fumes are irritating and can be harmful to health. Cadmium oxide fumes are particularly poisonous.
Operator well-being and safety will result from following the precautions given in this data sheet and those basic rules of safe brazing practice summarised on the last page.
Potential health and safety problems in brazing may arise in the following areas:-
1. Metal and metal oxide fumes from the brazing alloys
2. Fumes from heating the flux
3. Fumes from brazing torches
4. Equipment used to effect the brazed joint