Frequently Asked Questions About Electronic Waste

What are the contaminants of concern in old electronics and what are their pathways?

Electronic equipment contains metals and other materials that can be hazardous to human health and the environment if they are not properly managed.

Cadmium -- found in chip resistors, infrared detectors, and semiconductors. Cadmium can accumulate in,and negatively impact, the kidneys. Cadmium is persistent, bioaccumulative, and toxic. The principal exposure pathway is through respiration and through our food.

Lead -- found in glass panels in computer monitors and in lead soldering of printed circuit boards. Lead can cause damage to the central and peripheral nervous systems, blood systems, and kidneys in humans. Lead has also been shown to have negative effects on the development of childrens' brains. Lead can accumulate in the environment and have a detrimental effect on plants, animals, and humans. Consumer electronics may be responsible for 40 percent of the lead found in landfills. The principal pathway of concern is lead leaching from landfills and contaminating drinking water supplies.

Mercury -- found in thermostats, position sensors, relays and switches (e.g., on printed circuit boards), discharge lamps, and batteries. It is also used in medical equipment, data transmission, telecommunications, and mobile phones. When mercury make sits way into waterways, it is transformed into methylated mercury in the sediments. Methylated mercury accumulates in living organisms and travels up the food chain. Methylated mercury can cause brain damage. The principal exposure pathway is through our food.

Hexavalent Chromium or Chromium VI -- can be used to protect against corrosion of untreated and galvanized steel plates. Chromium VI can damage DNA and has been linked to asthmatic bronchitis. The major pathways are through landfill leachate or from fly ash generated when materials containing Chromium VI are incinerated.

Brominated Flame Retardants -- found on printed circuit boards, components such as plastic covers and cables as well as plastic covers of televisions. Although less is known about BFRs than some other contaminants of concern, but research has shown that one of these flame retardants, Polybrominated Diphenylethers (PDBE), might act and an endocrine disrupter. Flame retardant Polybrominated Biphenyls (PBB) may increase cancer risk to the of the digestive and lymph systems. Once released into the environment through landfill leachate and incineration they are concentrated in the food chain.

Additional concerns

Plastic -- Because manufacturers use many different types of plastic in electronic equipment, it is the most challenging to recycle. These plastics often include contaminants such as metal screws and inserts, coatings and paints, foams, and labels. Currently, plastics from electronic equipment are both difficult and costly to sort for single resin feedstocks markets and there are limited markets for the mixed plastics stream. Also, plastics can be treated with brominated flame retardants, making them harder to recycle and possibly dangerous to those exposed to them.

Additionally, electronics are made with valuable resources such as precious metals, engineered plastics, glass, and other materials -- all of which require energy to manufacture. When equipment is thrown away, these resources cannot be recovered and additional pollution will be generated to manufacture new products out of virgin materials.

How do you choose a reuse or recycle option?

Define clear objectives of what you want to be done with the equipment and the ultimate disposition of the equipment and/or component parts. Consider asking the following questions:

Reuse and Donation

  • Do you want to provide a community service by donating equipment?
  • Do you want a tax deduction for your contribution (ensure that the organization is a not-for-profit corporation as defined by the Internal Revenue Service (501(c) tax exempt status)?
  • What are your data security needs?


  • What are your data security needs?
  • Do you want your equipment back out in the resale market place?
  • Do you want the equipment demanufactured into raw materials (i.e. metals, plastics, glass) to be marketed as recyclables?
  • Do you want the equipment destroyed?

See "Where Can I Donate or Recycle My Old Computer or Other Electronic Products?" ( for organizations providing information on electronics donating and recycling opportunities in your area.

What percent of municipal solid waste (MSW) is electronics?

According to various reports, electronics comprise approximately 1-4 percent of the municipal solid waste stream. EPA is currently performing research to estimate the amount of production, generation, and recovery of consumer electronics occurring annually in the United States. This data will provide a specific breakout of the Miscellaneous Durable Goods Category currently reported in the MSW Characterization Report (also known as the Franklin Report -- see The European Union estimates indicate that electronic and electrical equipment waste is growing three times faster than municipal solid waste.

How do I choose a reputable company for demanufacturing/recycling?

If recycling is determined to be a viable option, consider asking the following questions:

  • How does the company verify data security?
  • How does the company handle the demanufacture and final disposal of all components, raw materials, and hazardous materials generated?
  • How long has the company been in business? Can the company provide a list of references to whom they currently provide service?

What is the concern with cell phones?

There is a large volume of cell phones retired each year, likely up to 130 million per year by 2005. Plus, in their circuitry, batteries, and liquid crystal displays, cell phones can contain toxics like arsenic, beryllium, cadmium, copper, and lead. Their plastic casings have also been treated with brominated flame retardants.

Visit "Ten Tips for Donating a Computer" to learn about extending the life of electronics through donation programs --

FAQs courtesy of EPA.

This article originally appeared in the 09/01/2005 issue of Environmental Protection.

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