Air pollution increases price of rubber products ^CHICAGO
™ s year air poilu· at tion will add ai least $500 million to the estimated $7.8 billion tab paid by retail purchasers of U.S. rubber products. Included are increased manufacturers' costs on these products which add upwards of $249 million, and product life shortened to the tune of $226 million. These estimates were reached by Dr. P. B. Stickney and W. J. Mueller of Battelle-Columbus Laboratories, Columbus, Ohio, after extensively studying those costs that can be charged to pollution. They described their results to the Division of Water, Air, and Waste Chemistry and have presented them to the National Air Pollution Control Administration. Ozone is the principal pollutant exacting this toll on rubber products. Long known for its degrading effect on rubber, the oxygen alio trope occurs naturally at background levels of 1 to 3 parts per 100 million. But it is also a component of photochemical smog and as such sometimes reaches levels of 25 to 30 parts per 100 million in certain areas. Other air pollutants such as nitrogen oxides, sulfur dioxide, and hydrocarbons have much less of an effect on rubber products. Styrene-butadiene rubber would be used in most cases where air pollution is not a problem. Hence, the two scientists start their cost estimates at the manufacturer's level by calculating the added cost of using specialty polymers as against S BR, after estimating to what extent specialty uses depend upon ability to resist ozone. Cost. For neoprene the estimated use for ozone resistance is 46 million pounds out of the estimated 264 million pounds used in 1969 at a cost charged to pollution of $12.6 million. Similarly, butyl rubber use because of ozone was 31 million pounds out of 202 million pounds at a cost of $1.5 million ; ethylene-propylene-diene monomer ( E P D M ) , 36 million pounds out of 121 million pounds, $2.34 million; chlorosulfonated polyethylene, 2.5 million pounds out of 30 million pounds, $0.8 million; and polysulfide, 3 million pounds out of 22 million pounds, $3.28 million. Specialty polymer use due to air pollution totals $20.6 million added yearly. Antiozonants or waxes incorporated into rubber products also increase ozone resistance. From U.S. Tariff Commission data, antiozonants use figures out to $34 million annually while half, or $5 million yearly, of wax use is charged to pollution. Other v
estimated costs at the manufacturer's level include those for protective coatings, paper wrappings (for tires, for example), and R&D costs for greater resistance to pollutants, which all total $26 million. Manufacturer costs were also estimated by another approach through a questionnaire sent to some 60 companies making a variety of rubber products, asking for estimates of yearly spending to protect against pollution and the value of the products protected. Extrapolated to the national level, the cost totaled $54 million. Replacement. Early replacement of rubber products failing prematurely
because of air pollution also adds significantly to costs. The two scientists estimate that $218 million worth of rubber products yearly, or 3% of total production, have a shortened life. Estimating that these products lost 25 to 50% of normal service because of air pollution, the actual yearly loss is put at $81 million. The Battelle-Columbus scientists were unable to accurately estimate other significant costs: labor to replace products, and the cost of replacing entire subassemblies when rubber products fail. Totaling all costs, then, by either of two methods, shows that costs at the manufacturer's level are either $161 million or $167 million. With industry estimates indicating that a reasonable markup at retail would multiply these figures by three, the total national cost is placed at at least $500 million yearly.
Air pollution adds costs at manufacturer's level Type of cost Specialty polymers Wax Antiozonants Calculated from questionnaire Replacement of failed products Miscellaneous (protective coatings, wrapping tires, research) Total
From questionnaire data, million dollars
—
From compounding costs, million dollars
$20.6 5.0 34.0
$54.0 81.4 26.0
81.4 26.0
$161.4
$167.0
Nonmetallic stabilizers could broaden PVC's scope First details of a series of new nonmetallic stabilizers for polyvinyl chloride have been released by Stauffer Chemical Co. The stabilizers are aliphatic and aromatic thiolcarboxylic acids and anhydrides. Currently being selectively field tested, they could broaden uses for PVC, particularly for packaging foods. The major properties and advantages of the new developmental stabilizers were described by Stauffer's Dr. Walter Stamm to the Division of Organic Coatings and Plastics Chemistry during a symposium on polyvinyl chloride stabilization. In a separate paper, the primary shortcoming of the Stauffer stabilizers—color development at high processing temperatures—and how this problem can be overcome were discussed by Dr. Lewis B. Weisfeld of Cincinnati Mil-
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acron Chemicals, Inc., New Brunswick, N.J., one of several firms currently evaluating the compounds. The most widely used PVC stabilizers today are metallic—typically dialkytin, barium, cadmium, and lead compounds. Stauffer's work has been focused on nonmetallic compounds, however, since they may cost less and are much less toxic. Lower toxicity stabilizers could pave the way to wider use of PVC for packaging foods. Stauffer's new developmental stabilizers provide better protection against heat degradation of PVC than other nonmetallics, Dr. Stamm says. More important, their heat stability as determined in the Brabender plastograph (which measures the melt viscosity of the PVC resin ) is about equal to the commercially used dialkytins. Best performance. Dr. Stamm and his coworkers Adam F. Kopacki and SEPT. 28, 1970 C&EN 55
