Environmental requirements
Flame retardants
Flame retardants are present in printed circuit boards, cables, wires, casings and
housings. Their purpose is to prevent, or at least to delay the spread of fire. Up to 30% of
the plastic in a computer casing can consist of flame retardant substances. Most flame
retardants contain bromine or chloride, and those flame retardants are chemically related to
another group of environmental toxins, PCBs. Both the flame retardants containing bromine
or chloride and the PCBs are suspected of giving rise to severe health effects, including
reproductive damage in fish-eating birds and mammals, due to the bio-accumulative*
processes. Flame retardants have been found in human blood and researchers fear that
disturbances in foetus development may occur.
The relevant TCO’99 demand requires that plastic components weighing more than 25
grams must not contain flame retardants with organically bound bromine or chlorine. Flame
retardants are allowed in the printed circuit boards since no substitutes are available.
Cadmium**
Cadmium is present in rechargeable batteries and in the colour-generating layers of
certain computer displays. Cadmium damages the nervous system and is toxic in high doses.
The relevant TCO’99 requirement states that batteries, the colour-generating layers of
display screens and the electrical or electronics components must not contain any cadmium.
Mercury**
Mercury is sometimes found in batteries, relays and switches. It damages the nervous
system and is toxic in high doses. The relevant TCO’99 requirement states that batteries
may not contain any mercury. It also demands that mercury is not present in any of the
electrical or electronics components associated with the labelled unit.
CFCs (freons)
The relevant TCO’99 requirement states that neither CFCs nor HCFCs may be used during
the manufacture and assembly of the product. CFCs (freons) are sometimes used for washing
printed circuit boards. CFCs break down ozone and thereby damage the ozone layer in the
stratosphere, causing increased reception on earth of ultraviolet light with e.g. increased
risks of skin cancer (malignant melanoma) as a consequence.
Lead**
Lead can be found in picture tubes, display screens, solders and capacitors. Lead damages
the nervous system and in higher doses, causes lead poisoning. The relevant TCO’99
requirement permits the inclusion of lead since no replacement has yet been developed.
* Bio-accumulative is defined as substances which accumulate within living organisms.
** Lead, Cadmium and Mercury are heavy metals which are Bio-accumulative.