Document 7jRrQ0ox65mEKVbKXDY26g7R

23471001 Environment PACKAGING OF FOOD and other product! i* a major market for polyvinyl chloride. Second thoughts on using PVC Packagers stick with PVC, but seek substitute materials for new products and as hedge against possible forced cutbacks Continued discovery of liver cancer cases among workers in polyvinyl chlo ride plants is posing a threat to the mate rial's future in the packaging field. Sev eral food manufacturers are dropping plans for packaging new products in the controversial plastic and PVC users are searching for possible substitutes in case federal regulations covering worker expo sure force cutbacks in output At 325-million-lbs./year consumption, packaging is a major outlet for the 4.6 bil lion lbs./year of PVC resin produced. And the reluctance of food packagers to use PVC could signal the beginning of harder times ahead for the material. Reports earlier this month of two cases of angiosarcoma in Czechoslovakian PVC plants has raised the toll to 24. And as those numbers mount, public pressure is building on the Occupational Safety and Health Administration to promulgate its "no detectable level" exposure limit for vinyl chloride monomer in work envi ronments. With the final standard due Oct S, OSHA is said to be seeking a com promise position that will avoid lawsuits from industry on the one side and labor and consumer groups on the other. One source tells Chemical Week that "trial balloons of 20-25 ppm. have been lofted by the agency." Industry representatives have been contending that imposition of a no detec table level limit--essentially 1 ppm.--for worker exposure is technically impos sible. Enforcement of such a standard, they claim, would cause shutdown of all PVC plants in the U.S., eliminate 1.7-2.2 million jobs in consuming and related in dustries and result in a loss of domestic production value of $65-90 billion/year. Manufacturers of substitute materials are not crowing over PVC's setbacks. Most, suffering feedstock shortages, are struggling to satisfy their own markets. Moreover, for many applications, there is no substitute for PVC. And the vinyl industry's occupational health problems may be precursors of difficulties for other segments of the or ganic chemical industry. "It's only one tree in the forest," says Cesare Maltoni, of the Institute of Oncology (Bologna, Italy), whose research first predicted the link between VCM exposure and cancer (CW, July 17, p. 30). The National Institute of Occupational Safety and Health has taken on the task of developing work exposure standards for some 400 chemicals by 1976. By No vember the agency hopes to publish ex posure standards it has developed for five ketones--2-butanone; cyclohexanone; 2pentanone; hexone; and acetone. It had hoped to have 40 chemicals completed. but "underestimated the difficulty." NIOSH also will be getting approxi mately 18 standards per month from three consulting groups: Stanford Re search Institute, Kaiser Foundation and Arthur D. Little. Future Unclear. Opposing what he called "blackmail" over the alleged con flict between job losses and worker safety, Peter Bommarito, president of the United Rubber Workers and chairman of AFLCIO's health and safety committee, says "this country survived for nearly 200 years without PVC and we can survive in the future without it" But Arthur D. Little (Cambridge, Mass.), in its examination of the possible demise of the PVC industry for the Society of the Plastics Industry says: "It would not be possible to duplicate the exact properties of vinyl plastic products by using substitute raw materials." And even if it were possible to find a product with the exact or equivalent properties, says ADL, cost. of production would probably price the Substitute out of the market "Choice of a packaging material is a series of complex considerations," says an industry observer. For many applications^ it's difficult if not impossible, to find- a material that fits the bill exactly. PVC has clarity and excellent oxygen and carbon dioxide barrier qualities. Polypropylene does not On the other hand, polypropyl ene is a tough construction material. According to Modem Plastics' 1973 survey on plastics production, some 79 million lbs. of PVC were used for bottles, compared with only 19.8 million lbs. of pdpropylene for the same purpose. And while polypropylene is more available: than PVC, a Phillips Petroleum spokes man says, "We don't have that much." Search for Substitutes: There was an earlier spur to the search for PVC substi tutes when a problem arose with the test marketing of half-gallon PVC bottles for. liquor in 1973. Alarmed by reports of VCM migration into the liquor, the Food and Drug Administration proposed to drop to zero the allowable VCM migra tion into food, drugs and cosmetics on May 9, 1973. Almost immediately, the Bureau of Alcohol, Tobacco and Fire arms cancelled its approval for the test marketing of the half-gallon PVC liquor bottles. (Final FDA decision on VCM migration limits is still pending.) According to one packaging supplier, "We lost some business in PVC over the liquor decision, and it was picked up by our glass operation." Glass is probably the best qualified al- July 31. 1974 CHEMICAL WEEK 19 BFG2565J Hpyironmentj imx*\i tentative across the board, but it, too, is in tight supply. For certain film applications, polyvinylidene chloride could benefit For ex ample, Dow notes that for odd shapes and barrier packs, such as for cheeses, it is "ideal" But a spokesman notes, it is more difficult to handle than PVC in ma chines, and it is more costly. Other packagers report little if any in crease in interest from marketers anxious to switch. But most agree that the PVC problem is influencing new-product in troduction. Case in point: Borden's ReaLemon Subsidiary, which was test marketing a line of cocktail mixes called On the Rocks in PVC containers. The PVC packaging idea has been dropped. "We're exploring a number of alterna tives," a spokesman reports. Opinion seems unanimous that large market shifts from PVC would be impos sible to soak up. Construction is the larg est consumer of PVC resins. Last year, for example, 1.34 billion lbs. of PVC were used to make pipe and fittings. That's more than 25% of total PVC consump tion, estimated by the SP1 to be 4.6 bil lion lbs. in 1973. An additional 464 mil lion lbs. went into flooring. And siding use as well as.miscellaneous construction applications pushed total construction markets for PVC well over 2 billion lbs. in 1973. Auto upholstery, seat covers, mats and decorative tops accounted for 256 million lbs. - PVC output has risen about 70% dur ing the past five years, for a compound growth rate of about 11%/year from 1968 to 1973. This year's growth, however, is likely to be much slower. Output during the first five months of 1974 was up only 1.7%, according to data compiled by the Tariff Commission. That's partly an indi cation of slackening growth in demand but also reflects shortages of capacity. Reactor Role: Of the 24 reported cases of angiosarcoma linked to VCM expo sure, only one, in Sweden, involved a worker at a monomer plant Of the rest, 20 were in PVC plants, two among com pounders and fabricators (one wire extru sion plant, one plastic fabric plant) and one West German worker engaged in fill ing aerosol pesticide containers with a VCM propellant Because vinyl chloride plants are gen erally automated they can be built with out enclosures. But PVC production is la bor-intensive, and in the colder climates it's necessary to enclose the plants. "Less than half are open," estimated one com pany spokesman. Goodrich has an nounced that it plans to build an "out- 20 CHEMICAL WEEK July 31. 1974 door" PVC plant alongside its Louisville oppose use of respirators, too. "Have you plant, where the VCM-angiosarcoma link ever tried working all day with a respira wu first reported last January. tor on?" asks Tony Mazzochi of the Oil, Four basic polymerization processes Chemical and Atomic Workers union. are used for PVC production--suspension One possible answer is to collect the es (which accounts for more than 75% of the caping monomer and vent it to the atmo- tonnage), emulsion, solution and bulk. ' sphere. But the Environmental Protection The reactor or autoclave, where polymer Agency, concerned about escaping mono ization takes place, is the key piece of mer, has been monitoring the air around equipment in each. Conversion of 85% of 10 PVC plants. "When OSHA gets the monomer is considered high. Un through EPA will move in and won't reacted monomer is removed from the want monomer going out the stack," says unit by vacuum for recycle to the process a Union Carbide spokesman. EPA con before the polymer is fed into a drying tends that there are 6% VCM losses from tower or storage tank. PVC plants and concentrations of 1-2 . Moreover, some polymer sticks to the ppm. in air outside plants. reactor sides, hardens and accumulates, Another* possibility: absorbing the lowering the heat transfer in the units. monomer in the vent gases on activated When the heat transfer becomes too low, carbon. Calgon has reported successful or a different resin is produced, it be laboratory studies of the technique and is comes necessary to clean the reactors. - ' installing a system for the effluent from High-pressure water jets are used pri the vent condensers at a southwest PVC marily to do the bulk of the cleaning. But plant The company says the monomer in some older plants, the ports in small can be regenerated with steam. kettles are positioned so that water jets But other companies are skeptical say can't be used. Some efforts are under way ing relatively concentrated streams of inert gases with relatively small amounts It will be impossible to duplicate exact properties of vinyl of oxygen are needed for activated car bon absorption. One company reports its estimated cost for activated carbon scrubbing in its resin-drying operation at $500,000 per stack. Chemical Carcinogens: Maltoni is al to develop new monomer-absorption, ready looking for other chemical carcino hardened resin removal methods. For ex gens, based on evidence supporting his ample, GAF has patented a solvent addi predictive cancer techniques. He is sus tion method. picious of all carbon-chloride groups. One producer's engineer, who has Maltoni is also doing more work on worked around PVC plants and been ex VCM, studying inhalation doses of 25 posed to the monomer for over 20 years, ppm. down to 1 ppm. and doing tests on thinks companies will have to "sharpen the effect ofingestion. up polymerization techniques and meth "I'm sure 25 ppm. will show cancer, ods of stripping free monomer." too," says Joseph Wagoner, chairman of He would like to see free-monomer NIOSH's occupational carcinogen com concentrations in the dryer reduced to mittee. 500 ppm., claiming they are now up to `There's no way to demonstrate the 3,000-4,000 ppm. on resin leaving the safe level of a carcinogen," he warns. plant "The plant of the future--if we Wagoner is also concerned that other dis- K have one--will be able to strip most of the eases may be caused by worker exposure free monomer," he says. to VCM. While critical of. the "serious Meeting Standards: Acknowledging limitations" 0f the Tabershaw-Cooper that the 1-ppm. standards are "going to epidemiological studies sponsored by the be tough to achieve," Daniel Boyd, direc Manufacturing Chemists Assn., he notes tor of OSHA's standards development of that they demonstrated brain and lung fice, says a combination of engineering damage linked to VCM exposure. controls, work practice methods and res Occupational health standards may be pirators could be used. one of the greatest problems the chemical A spokesman for one manufacturer industry has faced. But great optimism says he fears "we'll be hung with hose-fed and faith in'the industry has been ex positive pressure masks." All sources pressed in tome unexpected quarters. agree that self-contained supply packs, "The ingenuity of American industry similar to those used by astronauts, never fails to surprise me," says NIOSH's couldn't be used because the workers Wagoner. "Somehow, surprising things couldn't function. In fact, labor sources can be done." BFG25652