Rosin based solder flux fume is produced when soldering. This fume is a top cause of occupational asthma.
It affects workers in the electronics and assembly industries.
See COSHH Essentials for detailed advice on control.
Fume extraction - a soldering booth is best. On-tip extraction blocks up swiftly and needs frequent cleaning. Bench-mounted boxes are of limited use unless fitted with a HEPA filter.
Maintain the fume extraction system regularly.
Guidance specific to welders is also available.
These case studies are all real incidents with real and often serious long-term consequences for the people involved.
You can find more guidance and information for solderers on the Asthma publications pages.