Electronic Parts/Guidelines - infoHouse

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Again, industry figures are unavailable, but one study on polystyrene manufacturing lists energy
requirements at 120-180 kWh of electricity and approximately 5.000 kg of steam in producing one ton of
product .
Water Use: Water is used primarily for flushing and cooling purposes during the manufacture of
styrene and polystyrene. Industry figures on this process were not available. However, one study
cited 154 cubic meters of cooling water used per metric ton of material, a figure which does not include
flushing and cleaning uses. Styrene production accounts for the discharge into "receiving waters" of
1.7 Ibs. of water per 1,OOO Ibs of product. The industry reports that these discharges may include
biological oxygen demand, chemical oxygen demand, suspended solids, dissolved solids, oil and
grease, sulfides, and various metals including lead, mercury, iron, and aluminum.
Air Emissions: There are large differences in air emissions between the manufacture of
styrene/polystyrene resin and the polystyrene expansion process. While production of styrene resin
emits .2 Ibs of emissions per 1,000 Ibs of product, foam sheet polystyrene production emits 25 Ibs of
emissions per 1,ooO Ibs of product, and post-consumer polystyrene recycling is even higher at 27 Ibs of
emissions per 1,ooO Ibs of product. The culprits are the blowing agents used in both virgin and recy-
cled polystyrene foaming (expansion) processes. These blowing agents cannot be easily captured and
recycled, and most are discharged to the air. While the industry has significantly reduced its contrib-
utions to stratospheric ozone depletion by reducing and eliminating CFCs as blowing agents, substitute
agents continue to generate environmental impacts. HCFCs, which have frequently replaced CFCs in
the process, generate approximately 5% to 10% of the ozone depleting effect as their predecessors.
Pentane, another popular CFC substitute, is not a stratospheric ozone depleter, but is a contributor to
atmospheric ozone and thus to smog and global warming.
Hazardous Waste: Hazardous waste generated from styrene/polystyrene production include cleaning
and flushing solutions, solvents, lubrications, and inks. The 1991 industry "White Paper" on Styrene
and Polystyrene Manufacture and Use did not release its figures for hazardous waste generation as it
did for air and waterborne emissions and solid waste. However, that same paper indicated that indi-
vidual plant facilities have in the past generated several hundred thousand tons of hazardous waste
annually, pointing to a major impact industry-wide. Efforts in recycling and source reduction for these
materials has generated significant decreases in many cases, but hazardous chemical waste gener-
ation, transportation, and disposal remain a major environmental impact of the styrene/polystyrene
manufacturing process.
7.5.2.3 Packaging Material Usage
Reusability: Most polystyrene used in electronics packaging is used once. Attempts to establish
reuse systems for polystyrene caps and other electronics industry packaging are described in other
sections of the Guide.
Recyciabllity: Uncontaminated polystyrene is technologically recyclable into new plastic products. In
response to recent demand for recycling systems, the polystyrene industry has set a goal to recycle
25% of the polystyrene used in food service and packaging applications by 1995, and several regional
recycling facilities have been opened. Recycling is becoming widely implemented and is expected to
eventually reduce the use of virgin materials in the manufacture of polystyrene.
Inclneratlon: Polystyrene is well suited for incineration, if this process represents the best choice for
municipal solid waste handling. Polystyrene has an energy value of 18,400 Btu/pound, nearly as effi-
cient as fossil fuels. Because most of the energy is released as heat, ash is minimal with very little
toxicity. Refer to Table 11 on page 63 for energy content of other materials.
CompostabilitylDegradabiiity: Polystyrene is unsuitable for composting purposes as it does not
degrade organically and is inert in landfills.
60 Environmental Packaaina Guidelines