Nitrosamines found in tire-making plant - C&EN Global Enterprise

Oct 15, 1979 - First they were found in bacon, beer, cosmetics, and cars. Now the National Institute for Occupational Safety & Health reports finding ...
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Industry investment targets worldwide show chemicals in first place with 18% of all investments. Hardware industries of various types took the next few places—electrical machinery with 13%, nonelectrical machinery with 11%, and transpor­ tation equipment with 8%. By origin of investment, the U.S. still comes out first, with 26% of all investments going to other countries. Next is West Germany with 16%, followed by the U.K. with 14%, Japan with 10%, Canada with 9%, France with 7%, Switzerland with 4%, and the Netherlands with 3%. For investment projects in the U.S., the leading sources are considerably changed from two years ago. West Germany leads in 1979, displacing Canada, which was first in 1977. Second this year is the U.K. Third is

a fast-rising Japan, which has pushed Canada into fourth place. The Conference Board cites a number of reasons for the present popularity of the U.S. Companies in countries with strong currencies want to overcome the problem of lesscompetitive exports. Other com­ panies simply want to get a share of the U.S. market or avoid U.S. tariffs. In addition, U.S. assets are tempt­ ingly priced because of the weak dol­ lar, the depressed U.S. stock market, relatively slow-rising labor costs, es­ calating international transport prices, and political stability. For investment projects, the Con­ ference Board counts both new projects and acquisitions of existing enterprises if the latter transfer 51% or more of equity ownership. Joint ventures also are included. D

Sulfur-asphalt blend poised for paving use During the past few years, sulfur has been making promising inroads as a substitute for asphalt in pavements. Now, with the completion of a major commercial sulfur-asphalt paving project in Illinois, the technology seems ready to take off as a commer­ cial venture in the U.S. Under the auspices of the Illinois Department of Transportation, eight miles of Illinois Route 49 have just been resurfaced and widened with about 20,000 tons of sulfur-asphalt at a cost of $1.3 million. The project used a sulfur-asphalt technology in­ vented by Frank E. Pronk and de­ veloped and licensed by the Sulphur Development Institute of Canada (SUDIC), Calgary, Alta. Rather than using the standard asphalt binder, the Pronk process replaces up to 40% of the asphalt with

Asphalt and sulfur are blended in portable unit in earlier trial of Pronk process 8

C&EN Oct. 15, 1979

molten sulfur. The resulting emul­ sion, stabilized with an additive, is mixed with regular aggregate (sand, stone, crushed rock) to form the paving material. Several benefits ac­ crue: • Asphalt derived from increas­ ingly scarcer and more costly petro­ leum is replaced with lower-priced and more abundant sulfur. • Lower quality—thus more eco­ nomical—aggregates can be used. • Thinner pavements are made possible because sulfur asphalts are stronger and more durable than con­ ventional pavement. • Fuel costs for producing the sulfur-asphalt mix are reduced. Gulf Oil Canada Ltd., another firm developing sulfur-asphalt technology, uses a somewhat different emulsion process that involves the use of a specially designed blender, but the end product is essentially the same as Pronk's. This technology is one of two basic approaches to sulfur-containing as­ phalts. The second approach, devel­ oped by Shell Canada Ltd., uses the conventional asphalt binder but re­ places high-quality aggregate with a mixture of sulfur and sand. In addition to the Illinois paving project, two other Pronk sulfur-as­ phalt placements were made this year in Minnesota and Washington. The $300,000 Washington program in­ cluded construction of a doughnutshaped test track that is being used to assess the long-term durability of sulfur-asphalt. Thus far, Gulf Oil Canada has laid 15 test roads in the U.S., Canada, and the Netherlands, and will begin building its first in Saudi Arabia next month. D

Nitrosamines found in tire-making plant First they were found in bacon, beer, cosmetics, and cars. Now the Na­ tional Institute for Occupational Safety & Health reports finding three nitrosamines in air samples captured near hot processes at a tire manufac­ turing plant in Cumberland, Md. NIOSH was requested by a union representative to sample workplace air at Kelley-Springfield Tire, a sub­ sidiary of Goodyear Tire & Rubber, because iV-nitrosodiphenylamine, a recently discovered animal carcino­ gen, is used as a retarding agent in the manufacturing process at this plant. The agency surveyed the plant on July 29 and Aug. 1, collecting process air samples. It surveyed the plant again on Oct. 3 to 5, collecting both process and breathing-zone samples. And it will return again to collect bi­ ological samples, from which worker body burdens can be determined. Analyses of process samples col­ lected during the first surveying effort revealed N-nitrosodimethylamine, iV-nitrosopyrrolidine, and iV-nitrosomorpholene. Of the three, N-nitrosomorpholene was the prevalent species at all the hot processes sam­ pled, but it was the highest—248 mi­ crograms per eu m in one sample—at the calender where rubber is spread over the tire fabric. All three com­ pounds, however, are animal carcin­ ogens, and are treated by NIOSH as suspect human carcinogens. The source of the compounds is not known. However, NIOSH hypoth­ esizes that preformed precursors could be added to the batch material, and by trans-nitrosation in the hot processes convert to the nitrosamines ultimately detected, or the detected compounds could come from the breakdown of the retardant ΛΓ-nitrosodiphenylamine. NIOSH project officer James McGlothlin stresses that only the first survey results are available, and they do not represent concentrations to which the 400 workers are actually exposed. The next two surveys will produce more meaningful healtheffects information, he says. The Cumberland, Md., plant was the first in the country to be moni­ tored for nitrosamines volatilized from hot manufacturing processes, and neither NIOSH nor KellySpringfield was prepared for the ini­ tial findings. McGlothlin has recom­ mended modifications to the venti­ lation systems, especially at the cal­ ender where nitrosamines-laden air is drawn across the worker's breathing zone. The company is acting quickly on the recommendation. D