Summary of Toxic Materials in Electronics Products
SOURCE: U.S. Environmental Protection Agency (EPA)

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

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 food.

Lead—found in glass panels in computer monitors and 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 children's 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 makes its way into waterways, it is transformed into methylated mercury in the sediments. Methylated mercury can cause brain damage.

Hexavalent Chromium or Chromium VI—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 fly ash generated when materials containing chromium VI are incinerated.

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

Plastics—Because manufacturers use many different types of plastic in electronic equipment, it is very 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 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.