Environment and Electronics
Brief introduction to the restriction
of harmful materials in electronics
Materials such as lead(Pb), Cadmium(Cd) , Mercury(Hg) which
are popularly used in electronics are harmful to bio-life.
Fall in the IQ level of the children, brain damage, kidney/thyroid
damage are few harmful effects on human-life from these
materials. The plants, sea-life and all the other bio on
earth will degrade and suffer due to these chemicals.
After continuous protests by environment related organizations,
the industry is now pressured to contain and finally fully-eliminate
the use of hazardous substances.
The two great initiations in this direction are, WEEE (Waste
Electrical and Electronic Equipment directive) and RoHS
(Restriction on certain Hazardous Substances).
RoHS is a directive of the European Parliament (Directive
2002/95/EC; 27 January 2003) that, as its name implies,
calls for manufacturers to restrict the use of hazardous
substances in electrical equipment. The goal is to reduce
human exposure to these materials through the ordinary use
of products and to reduce the amount of hazardous material
introduced to the environment when the products are eventually
recycled or disposed of. The directive is legally binding
on any company that wishes to sell product within the EU.
Practically speaking, it applies to all equipment OEMs and
all products worldwide as most will not wish to design and
manufacture Europe-only products. Many OEMs have, in turn,
made it binding on their suppliers if they want to sell
The member states shall ensure that, new electrical and
electronic equipment that will be sold in the market does
not contain lead, mercury, cadmium, hexa-valent chromium,
polybrominated biphenyls (PBB) and polybrominated diphenyls
(PBDE). Except for Cadmium, the threshold level is 0.1%
by weight of Homogeneous material and for Cadmium the threshold
level is 0.01% by weight of Homogeneous material, effective
from 1st Jul 2006.
Home appliances, computers, telecommunication, lighting
and consumer equipments, toys, automatic dispensers, electronic
and electric tools, electric light bulbs and luminaries
in households are the industries covered by RoHS. Few exemptions
granted are Lead in electronic ceramic parts, Lead in solders
for servers, storage array systems, Lead in solders for
network infrastructure equipment for switching, signalling,
transmission as well as network transmission management
for telecommunication, etc., These exceptions are to be
reviewed every 4 years.
Most dangerous hazardous substances"
1. Lead (Pb) can be easily absorbed by living organisms
(including humans) and can cause multiple health and environmental
problems. Lead (Pb) is ubiquitous in almost all electronic
2. Cadmium (Cd) can be absorbed easily by organisms and
ecosystems, will accumulate over time and is considered
toxic and carcinogenic. The 2002/95/EC directive limits
the maximum level of Cd at 100 ppm. Cadmium is used primarily
in Cd-Ni batteries, but can also be electroplating applications
as well as in pigment that can be added for coloring and/or
stabilizers in plastics which are heat resistant. Other
uses include solder and electroplating, as well as industrial
3. Mercury (Hg) is a toxin that can easily be absorbed
through contact via the skin or respiratory system, and
Hg will accumulate in the bloodstream and eventually attack
the central nervous system. Mercury (Hg) has historically
been used in such devices as thermometers, barometers and
other types of medical products, as well as automotive parts,
batteries and fluorescent lighting fixtures.
4. Hexavalent Chromium (Cr6+) is a known carcinogen. Hexavalent
Chromium-Cr6+ (also known as Cr VI) has been commonly used
as a coating on a variety of materials, often to act as
a corrosion inhibitor. Cr6+ can also be used in pigments,
dyes, paints, inks, textiles, plastics and a host of other
Ø Brominated flame retardants (BFRs), PBB and PBDE
have been targeted by RoHS legislation as they are suspected
to be carcinogenic. Additives have been used for years in
commercially available plastics to make the polymers flame
retardant and also in the connectors.
Continued in the next article: Alternates for the restricted
There will be a series of articles atleast for the 1st
quarter of 2009 covering environment issues related to electronics.