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Department of Engineering Health & Safety


Soldering Safety

Read risk assessments and chemical safety information before starting work.  These should be readily accessible from the soldering station.


Make sure you know what is in your solder, it is not always apparent on the reel label. If in doubt, ask.


Soldering Iron

  • Never touch the element of the soldering iron....400°C!
  • Hold wires to be heated with tweezers or clamps.
  • Keep the cleaning sponge wet during use.
  • Always return the soldering iron to its stand when not in use. Never put it down on the workbench.
  • Turn unit off and unplug when not in use.

Solder, flux and cleaners

  • Wear eye protection.  Solder can “spit”.
  • Use rosin-free and lead-free solders wherever possible.
  • Keep cleaning solvents in dispensing bottles.
  • Always wash your hands with soap and water after soldering.

Lead exposure

  • Lead can give rise to serious chronic health effects.  Exposure will primarily be through accidental ingestion from your skin, wear gloves if directly handling solder.  Limited fumes may be generated by soldering. 

Rosin exposure

  • Rosin (colophony, ersin) is a resin contained in solder flux.  Flux generates the visible fumes seen during soldering.  Exposure to rosin can cause eye, throat and lung irritation, nose bleeds and headaches.  Repeated exposure can cause respiratory and skin sensitisation, causing and aggravating asthma.  Rosin is a serious occupational health hazard.

Control of fumes

  • Soldering using rosin is only permitted in strictly controlled conditions after discussion with the Safety Office where there is no effective alternative.  Fume extraction should be through an enclosed hood (preferred) or tip extraction.  Ideally these should vent to the outside.  Tip extract units that use filter boxes should include both activated carbon and HEPA filters.
  • Bench top filter extract systems may be used for rosin-free soldering in well ventilated areas (i.e. large volume work space or with mechanical air changes.  Placement of these is important to performance, if in doubt ask.
  • All extract systems should be tested at least annually and maintained (i.e. change filters regularly).  Keep a log of filter changes or mark date on filter/system.
  • Do not solder if extract is not working properly and report immediately.

Training and supervision

  • Supervisors/line managers should inform users of the risks from soldering.
  • Supervisors/line managers should ensure that controls are in place and working and that they are used correctly.
  • All those soldering should be trained and supervised appropriately.

Health Surveillance

  • All those soldering frequently (i.e. more than once a week) and any using rosin containing solders should be referred to the Safety Office for health surveillance.

Electrical Safety

  • Do not use soldering irons that have obvious damage to body, cable or plug.
  • All soldering irons should have had electrical safety (PAT) testing within the last twelve months.  If not, contact the on-site BOC representative.
  • Keep the soldering station free of electrical cables to prevent damage from the heated tip.
  • Use a grounded outlet and grounding prong if a short circuit is a possibility.

Fire Prevention

  • Work on a fire-proof or fire resistant surface.
  • Wear fire resistant clothing (e.g. 100% cotton) that covers your arms and legs to prevent accidental burns.
  • Know where your nearest fire extinguisher is and how to use it (Safety Office can arrange training).

First Aid

  • Immediate place any burns under cold water for 15 minutes.
  • Report to a first aider if deep or extensive otherwise protect with a plaster (band-aid).


  • Collect waste solder in a lidded container.  Replace lid when not in use.
  • Label appropriately and dispose of as hazardous waste (contact Safety Office).
  • Used solder sponges and contaminated rags should be placed in a sealable bag for disposal as hazardous waste.

Safety Office Contact Details



Inglis Building

Trumpington Street

Cambridge CB2 1PZ


Gary Steele

Department Safety Officer (DSO)

Departmental Fire Safety Manager (DFSM)

Tel: 01223 (3)32740


Steve Wickens

Department Safety Coordinator

Tel: 01223 (7)61455