Use Nationally and in Massachusetts
Acrylonitrile is an intermediary chemical in manufacturing; it is used to produce other chemicals or materials. The dominant uses for acrylonitrile in the U.S. are in the manufacture of adiponitrile, acrylonitrile-butadiene-styrene (ABS) and styreneacrylonitrile (SAN) resins, acrylic fibers, acrylamide, nitrile elastomers, and acrylonitrile based polymers for packaging products.
Massachusetts, with its very small petrochemical manufacturing base, uses small amounts of acrylonitrile, only 222,000 pounds in 1996 (see Table 1). Reflecting national use patterns, Massachusetts companies “process” — intentionally incorporate the chemical into a product — acrylonitrile. Acrylonitrile is seldom “otherwise used” — not intentionally incorporated into a product. Because acrylonitrile is transformed in the manufacturing process, outputs in the form of byproduct, product, and environmental releases and transfers are quite low.
Table 1 includes two sources of “output” data: Massachusetts Toxics Use Reduction Act (MA TURA) and U.S. EPA, Toxics Release Inventory (TRI) data. The MA TURA database includes all non-product material created by a process line prior to release, on-site treatment, or transfer (“byproduct”) and the amount of toxic chemical incorporated into a product (“shipped in or as product”). The U.S. EPA, TRI database includes information on the waste materials generated by a facility after on-site treatment including: releases to air, land, and water (“environmental releases”) and transfers off-site for treatment or disposal (“off-site transfers”). The use of acrylonitrile in Massachusetts declined by almost 25% between 1990 and 1996. This decline differs markedly from national consumption of acrylonitrile, which grew annually at a rate of 5 percent between 1990 and 1993 and is projected to grow at a rate between 2 and 2.5 percent between 1994-1999. As shown in Table 2, Monsanto no longer reports use of acrylonitrile and Zeneca cut its acrylonitrile use in the manufacture of acrylic resin emulsions by almost 75% between 1990 and 1996. Conversely, the use of acrylonitrile in the manufacture of water-based coating compounds increased by over 100% between 1990 and 1996. Polymer Latex, for example, uses acrylonitrile to manufacture specialty coatings for use in the textile and paper industries.
Driving the decline in TURA byproducts was Monsanto’s decision to cease using acrylonitrile. In 1990, Monsanto generated 21,000 pounds of MA TURA byproducts, nearly all of which was transferred off-site. By 1995, their last year of reporting, Monsanto had reduced use to 18,000 pounds and byproducts to 1,400 pounds.