Hazardous components of electronic waste and where they are found

Electronic waste or e-waste often has hazardous or toxic components that can have an impact on the environment once the materials end up in a landfill or if they are improperly managed and disposed. Below is a list of hazardous or toxic components of e-waste and where they may be found:

• Antimony trioxide - a flame retardant, added to cathode ray tube monitor (CRT) glass, found in printed circuit boards and cables
• Arsenic - in older cathode ray tubes and in light emitting diodes
• Barium - in the CRT
• Beryllium - often allied with copper to improve copper's strength, conductivity and elasticity. Old motherboards, contact springs found in printed circuit boards, relays, and in the mirror mechanism of laser printers. In power supply boxes which contain silicon controlled rectifiers and x-ray lenses
• Cadmium - circuit boards and semiconductors Rechargeable NiCd-batteries, fluorescent layer (CRT screens), printer inks and toners, photocopying-machines (printer drums)
• Chlorofluorocarbon (CFC) - Cooling unit, Insulation foam
• Chromium - in steel as corrosion protection, Data tapes, floppy-disks, circuit boards, photocopying-machines (printer drums)
• Cobalt - component in steel for structural strength and magnetivity
• Lead - cathode ray tubes, solder, batteries, printed wiring boards (circuit boards), solder on components
• Lithium - batteries
• Mercury - switches (mercury wetted) and housing, fluorescent lamps providing backlighting in liquid crystal displays (LCDs) for monitors and laptops, batteries, printed circuit boards
• Nickel - batteries, electron gun in CRT , printed circuit boards
• Polybrominated flame retardants (including polychlorinated biphenyls (PCB), polybrominated biphenyls (PBB), Polybrominated diphenyl ethers (PBDE), and tetrabromo bis-biphenol-a (TBBA))- plastic casings, cables, and circuit boards, condensers, transformers
• Polyvinyl chloride (PVC) - Cable insulation
• Selenium - circuit boards as power to supply rectifier, photocopying-machines (printer drums)
• Zinc - interior of CRT screens, printed circuit boards

There are many sites that can provide more information on the toxics in e-waste, including:

http://latitude42.org/cgi-bin/view/Main/IctToxins

www.e-waste.org.za/hazmat.htm

www.smalldog.com/ewaste/index.html