• Solder is a metal with a low melting point, commonly used to create small bonds between metals, and to connect wiring in electronics. 1 Flux-core solder is commonly used by hobbyists for electronics, while special hard solders are used for jewelry making.


  • There are many types of solder made with different metal combinations. Common mixtures are Tin-Silver-Copper, Tin-Lead, and alloys of copper, zinc, and silver. 2 These metals are finite resources that must be mined from the earth using energy-intensive machinery. Flux-core solder contains pine rosin, a byproduct of turpentine manufacturing. 3


  • Mining is an energy intensive and destructive process, which damages the structural integrity of the land, destroys habitats, and causes erosion. 4 When products containing lead solder are landfilled, they can contaminate waterways and soil.

Human Health

  • Fumes from heated flux-core solder cause asthma, bronchitis and allergic reaction when one does not use breathing protection. 1 Flux fumes can also cause skin disease. 3 Handling lead deposits small particles on the skin that can be accidentally ingested and accumulated in the body. Lead damages the nervous, reproductive, digestive and muscular systems. 5

Social Equity        

  • The US government and EU provide requirements and incentives for manufacturers to use lead-free solders

Safe Use and Exposure

  • Wear eye protection and a respirator. Work in a well ventilated area to protect fellow students from exposure to noxious fumes. Wear heat resistant (fabric) gloves for protection from lead exposure. Wash hands with soap and water after soldering. Wear clothing that protects the arms and legs. Metal conducts heat away from the solder tip, so use a wire stand or third hand helper to avoid burns. Use a wet sponge to remove excess solder from iron tip.
  • Do not use lead solder in the same area where you work and eat! Lead will contaminate the work surface, where it can be easily transferred onto the hands and ingested when you touch your mouth. 5

Proper disposal

  • Place lead-solder waste in a labeled container and dispose of in the hazardous waste bin. 5 Usable solder can be donated to the givetake.

Safe Alternatives

  • Choose lead-free solders whenever possible.



  1. “The Hazards of Solder Fumes”, Sentry Air Systems,
  2. “Solder”, Wikipedia,
  3. Health Hazards From Inhaling and Exposure to Soldering Fumes,
  4. “Environmental Risks of Mining”, Massachusetts Institute of Technology,
  5. Lead Soldering Safety Guidelines,