Green Tutorial:

 ><

Environmental Aspects of Electrical and Electronic Equipment (EEE)



When looking at the environmental aspects of electronics, there are four main areas of interest:

Some of the major reasons for being concerned about them are seen in the table below:



Environmental Aspect

Environmental Impact

Use of Materials

 Pollution and energy use from mining and refining of raw materials, use of non-renewable resources, destroying beautiful scenery etc.

Use of Energy

 Pollution from power plants (acid rain, NOx-gases, radioactive and other waste etc.), use of non-renewable fossil fuels

Chemical Substances

 Potentially toxic to humans and eco-systems. Emissions can occur during the whole life-cycle (mining and refining of raw materials, production, in the use- and end-of-life phases)

Waste deposit/
incineration

 Pollution of soil and ground water by leakage from waste deposits or ashes and slag, removal of non-renewable resources from circulation




Use of Materials

From the known resources and the present yearly consumption it is possible to calculate the so-called "Life Index". Life Index is the number of years the known resources will last, if the yearly consumption remains the same. Raw materials with a Life Index below 50 years are designated as depletable resources.

This does not necessarily mean, that the resources will be used up after this number of years, but it indicates that the price will rise along with a reduced amount of these raw materials and the rising costs for exploitation.





Use of Energy

Fossil fuels for energy production are limited resources, as can be seen from the figure below.

Energy prices will most likely continue to rise in the coming years, and for electrical and electronic equipment this means that Cost-of-Ownership will become an important parameter for the customer. So both from an economic and an environmental point of view it is important to design energy efficient equipment.







Stand-by consumption is important!

The stand-by consumption of electronic equipment in private households is about 10% of the total electricity consumption. The problem is illustrated with the following data for Set-top boxes (e.g. for cable-, satellite- and Internet access):


Example:

Fast Facts about Set-top boxes

from USA's Environmental Protection Agency (EPA), 2001
  • Data from the American Council for an Energy-Efficient Economy (ACEEE) and Lawrence Berkeley National Laboratory (LBNL) has indicated that the amount of energy used when "off" is nearly equal to the amount needed to operate set-top boxes in their primary function or active mode.
  • Cable, satellite, and Internet access set-top boxes, as well as video game consoles, consume an estimated 7 billion kWh per year, producing pollution roughly equivalent to that of over 1 million cars
  • Americans spend over $618 million on utility bills to power these electronic devices. Set-top boxes consume much of this energy while consumers are not watching television or using these products.




Chemical Substances

The authorities focus on chemical substances in electrical and electronic equipment. This is partly because of experience with substances used in older equipment and now seen as a problem in waste disposal (e.g. mercury, PCB). But also in today's equipment, new substances are suspected of having toxicologic impacts on environment.





Examples of potentially harmful substances

    Substance

    Reason for special attention
  • PCB (Poly-Chlorinated Biphenyls): until 1980 used as an additive to oil in high-voltage transformers, in capacitors for single-phase motors, and in ballast-capacitors for fluorescent lighting.
 PCB is very persistent and bio-accumulative, and suspected of causing reproduction-defects in e.g. birds of prey.
  • Cadmium (batteries, pigments).
The health and environmental effects of cadmium have been widely studied since the detection of adverse human health effects in Japan in the 1950s and 1960s (Itai Itai disease).

The most pronounced effects occur in workers occupationally exposed to high levels of cadmium fume or fine particle size dusts, and affect the renal and respiratory systems. In addition, small amounts of dissolved cadmium may be toxic to aquatic and terrestrial organisms.

According to the RoHS directive new electrical and electronic equipment put on the market from from 1 July 2006 should not contain cadmium.
  • Lead (solder, batteries, Cathode-Ray-Tube glass).
Processing of metallic lead may give rise to lead compounds, which are all classified as dangerous substances.

In humans, lead e.g. affects the central nervous system and the kidneys. Environmental toxicity has been reported in several organisms.

However, investigations suggests that the surface of metallic lead under certain conditions readily reacts in air, soil and water to form a protective and insoluble layer of inorganic lead compounds. Such inorganic compounds have a low bio-availability and uptake by terrestrial plants and animals, and will therefore generally reduce the likelihood and extent of toxic effects seen in the environment. An exemption from the above is acidic soil conditions with an increased risk of lead toxicity.

According to the RoHS directive new electrical and electronic equipment put on the market from from 1 July 2006 should not contain lead.
  • Mercury (switches, relays, fluorescent lamps for flat panel displays).
Elemental mercury is classified as a dangerous substance: toxic by inhalation with danger of cumulative effects.

Toxicity in humans is mainly effects on the central nervous system effects (CNS) and the kidney. Mercury is also classified as very toxic to aquatic organisms and may cause long-term effects in the aquatic environment.

According to the RoHS directive new electrical and electronic equipment put on the market from from 1 July 2006 should not contain mercury.
  • Beryllium (beryllia circuit substrates, heatsink compound, alloy material in springs).
Very toxic to humans by inhalation (Category 2 carcinogen) .
  • Softeners in polymers, e.g. phtalates
Suspected to cause hormonal disrupting effects.
  • Brominated flame retardants, additives to polymers, e.g. printed circuit boards such as FR4, and many plastic parts in electrical and electronic equipment.

Some brominated flame retardants are suspected carcinogens, some are suspected to cause reproductive effects and some may cause organ (especially liver) toxicity in humans.

Some of these flame retardants are very slowly degradable in nature, they are bio-accumulative, and some tests have shown generation of dioxines during incineration.

According to the RoHS directive new electrical and electronic equipment put on the market from from 1 July 2006 should not contain polybrominated biphenyls (PBB) or polybrominated diphenyl ethers (PBDE).

For more information:
"Brominated Flame Retardants: Toxicity and Ecotoxicity"
Environmental project no. 568, 2000, Danish EPA (download from www.mst.dk).
Hexavalent chromium (Cr 6+) often used for surface treatment , as it has good corrosionprotective properties Hexavalent chromium is toxic to humans and the environment. It is also a potent carcinogen (Category 1).

According to the RoHS directive new electrical and electronic equipment put on the market from from 1 July 2006 should not contain hexavalent chromium.


For more information about chemical substances in electronics, please see: EICTA - substances under special attention in EEE, or Lists of Banned or Restricted Substances.


Waste deposit/incineration

The waste amount from electrical and electronic equipment is rapidly increasing, partly because of the growing demand, and partly because of the still shorter life-cycle of this type of equipment.

Landfill is not a solution to this problem, both because of lack of landfill-sites, and because this constitute a risk for pollution from leakage of harmful substances.

Incineration is not a solution either. It causes pollution from gases, heavy metals and formation of poisonous substances in the slag, and also because valuable resources are lost in this way.

To minimise waste the solutions are:

1. Extended life of equipment (repair/upgrade)
2. Re-use
3. Recycling



Source: Advertisement from Inland Steel, USA

><