Page 158 - Design for Environment A Guide to Sustainable Product Development

Design Rules and Guidelines 137

One of the challenges in hazard reduction is the potential for
excessive control of suspect materials. While the evidence for some
environmental risks is overwhelming, others can be more specula-
tive. The precautionary principle can lead to restriction of substances
based on flimsy toxicological evidence, and it is not always clear
that the public benefit in terms of risk reduction is commensurate
with the economic burden of chemical substitution. In some cases,
there are unintended adverse consequences; for example, the substi-
tution of methyl tertiary butyl ether (MBTE) for lead in reformulated
gasoline resulted in widespread contamination of underground water
reservoirs.
The following are examples of guidelines for hazard reduction:

• Product reformulation—An effective way to avoid toxic re -
leases is simply to eliminate them by redesigning the prod-
uct. For example, brominated flame retardants in plastic
materials have been eliminated from many electronic prod-
ucts due to evidence of potential chronic toxicity. Some
companies have established lists of preferred and restricted
mate rials in an effort to avoid specification of toxic or haz-
ardous con stituents in new products. The practice of “green
chemistry” has expanded, as scientists explore ways to re -
formulate chemical products using alternative reaction path-
ways that are “cleaner” and safer (see Chapter 13).
Example: SC Johnson, the consumer products manufacturer, has
established a Greenlist™ program to classify all the ingredients that
go into its products according to their impact on the environment and
human health. For example, the company has made a considerable
effort to eliminate chlorine-based packaging, including PVC bottles.
In one case, the company reformulated a popular metal polish
product so that it could be packaged in a non-PVC bottle (PET), and
actually reduced overall life-cycle costs. The new formula uses fewer
chemicals, matches the performance of the old product, eliminates
the need for the E.U. “Dangerous for the Environment” hazard label,
and can be warehoused together with other products.
• Toxic and hazardous material use reduction—While older
plants can be retrofitted with pollution control devices, de -
signing “cleaner” processes is a more effective means of pol-
lution prevention. Avoiding the use of toxic or hazardous
chemicals is the best way to eliminate the associated risks.
As illustrated in Table 9.2, many companies have developed
lists of materials to be avoided due to their regulatory status
or known health and environmental hazards. For example,
materials containing certain flame retardants (e.g., PBDO’s)

may be restricted from normal re cycling channels due to
toxicity concerns. As discussed in Chapter 3, European Union
directives such as WEEE and RoHS have influenced global