Use Nationally and in Massachusetts
TCE was first produced in the early twentieth century and was used as a general anesthetic until the late 1970’s. TCE was also used as a solvent for extraction of palm, coconut and soy bean oils, spices, hops and the decaffeination of coffee. The United States Food and Drug Administration banned these uses as well as use in cosmetics and drug production in the 1970s.
According to the 2001 Chemical Economics Handbook, the breakdown of TCE use in the United States in 2005 is estimated as:
- 26% vapor degreasing of fabricated metal parts
- 74% chemical intermediates and miscellaneous uses
Metal Cleaning and Degreasing
TCE is used as a degreasing solvent in the metal finishing, automotive and aerospace industries. TCE is an important solvent for degreasing soft metals such as aluminum and works well cleaning steel before galvanizing. TCE has many properties that make it an excellent degreasing agent, including: high solvency; low flammability; non corrosiveness; and high stability. TCE is also relatively inexpensive and cleans thoroughly and quickly.
TCE in high purity grade is used as a feedstock to produce hydrofluorocarbon refrigerants and other chlorinated end products such as flame retardant chemicals. TCE is also used as a molecular-weight control agent in the manufacturer of polyvinyl chloride (PVC).
TCE is used as a solvent in adhesives and aerosol formulations. It is also used as a heat transfer medium as a solvent in electronics, printing, pulp and paper and in textile operations. Chlorinated solvents, such as TCE, are used in a number of operations in the textile industry. TCE is also used as a swelling agent in disperse dyeing of polyesters, for removal of basting threads, and in small quantities for scouring wool.
Since 1990 Massachusetts companies have reduced their use of TCE by more than a 77%.
In 2005 almost 90% of TCE uses in Massachusetts (excluding chemical distribution) were associated with solvent use in adhesives and paints.
Table 1 shows the amount of TCE use reported in Massachusetts in the first year of reporting (1990) and in 2005. Overall, companies in Massachusetts have reduced their use of TCE by more than 77% during this period. Most companies were able to reduce their use of TCE to below the 10,000 pound reporting threshold within 5 years of the beginning of the program. With the new lower reporting threshold (1,000 pounds/year starting in reporting year 2008) more companies will likely begin reporting on their use of TCE.
Figure 1 illustrates the percent changes in use of TCE in Massachusetts by industry sector over the years 1990 to 2005.
Manufactured Metal Products
The manufactured metal products sector includes companies manufacturing products such as binders, razors, lighting fixtures, motor vehicle parts, jewelry and other niche product lines. The companies in this sector used TCE to degrease or clean parts as part of their overall manufacturing processes. The companies in this sector were able to completely reduce their use of TCE below reporting thresholds, typically within seven years. At least two facilities, Lightolier and Swank, are still reporting on use of other chemicals.
Electronics and Wiring Devices
Of the nine companies reporting use of TCE in 1990, only one company, Tyco Electronics, reported continued use of TCE as a degreaser in 2005. Tyco reported a 97% reduction in TCE use in that time. According to staff at this facility, Tyco is no longer using TCE. After merging this location with its Norwood location Tyco is now using an alternative solvent for its degreasing operations.
The three companies in the Wiring Devices sector apparently reduced all reportable uses of toxic chemicals below reporting thresholds by 2003.
Metalworking and Fabrication
Generally companies in this sector use TCE as a cleaner and degreaser for metal parts. The Metalworking and Fabrication sector reduced its use of TCE by 97% from 1990 to 2005. Several of the companies in this sector are job shop operations whose customers largely dictate the processes required for plating.
While the majority of companies in this sector reduced their use of TCE below the 10,000 lb reporting threshold, several continue to use TCE, and it is likely that many more companies in this sector will report use of TCE above the new 1,000 lb/year reporting threshold for 2008. For example, some companies that had reduced their use of TCE to just below 10,000 pounds in 2005 exhibited a slow decline in use over time and would likely continue to use TCE well in excess of the new 1,000 pound/year threshold.
Chemical Preparations and Products (including Rubber Products)
Massachusetts companies in this sector use TCE as a synthesis feedstock for such products as paints, adhesives and cleaners. This sector experienced a 52% reduction in reportable TCE use from 1990 to 2005.
ITW TACC, which processes TCE with other chemicals to create adhesives, sealants and caulks for roofing, general construction and general industrial application, reported an almost 50% reduction in TCE use over the 15 year reporting period. On the other hand, Camger began incorporating TCE into its paint formulations in 1995, and has increased the amount of TCE used by over 30% since that time.
Shawmut Corp also uses TCE as part of its adhesives used in textile lamination applications. Shawmut decreased its use of TCE by almost 35% from 1990 to 2005, using process modifications and improved chemical management techniques. New England Newspaper Supply reduced its use of TCE below reporting thresholds within one year of having to report.
Chemical Distributors and Packagers
This sector reduced the reportable amount of TCE from 1990 to 2005 by 45%.
Both Safety Kleen and Shield Packaging reduced their sales of TCE-based products to below the reporting threshold by 2005. According to a statement made by Safety Kleen, its use of TCE is wholly dependent on customer demand. Therefore, we can infer that customers have significantly altered their contract degreasing solution choices away from TCE since 1990. Shield Packaging had reported over 20,000 lb of TCE in 2004. It is possible that it may again be reporting TCE as a result of the reduced reporting threshold.
Four chemical distributors, representing over 55% of the total reported use of TCE in Massachusetts, reported processing TCE in 2005, though none reported TCE above the reporting threshold in 1990. These companies repackage TCE for bulk sales to their customers.
According to the company statement provided by one of the companies, Ashland Distribution, “customer demand dictates the amount of TURA chemicals transferred at Ashland's Tewksbury facility. Ashland has been effective in reducing waste generation by implementing process improvements at the facility. While demand for chemical products may increase, thereby increasing the volume of chemicals handled (used) and transferred on site, the company is focused on limiting waste generation and releases. It continues to evaluate potentially viable process enhancements.” This statement describes the challenges facing chemical distributors and typical management of their toxic chemicals use.
Summary of Inputs and Outputs
Figure 2 illustrates the change from 1990 to 2005 in inputs and outputs of TCE in Massachusetts. Inputs include TCE that is manufactured or processed, as well as TCE that is “otherwise used” (i.e., ancillary uses that do not become incorporated into the final product). Outputs include TCE that is generated as byproduct (i.e., all non-product material created by a process line prior to release, on-site treatment, or transfer) and the amount of TCE that is shipped in or as product.
Both inputs and outputs of TCE were significantly reduced overall in the Commonwealth from 1990 to 2005. Specifically, from 1990 to 2005 the total input of TCE, including otherwise used, manufactured or processed TCE, was reduced by 77% while the total output of TCE, the amount generated as byproduct, shipped in or as product, over the same time period was reduced by 81%.
Endnotes: Chemical Economics Handbook, 2002, 632.3000Y, SRI International; IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man, 1972; Halogenated Solvents Industry Association, Trichloroethylene White Paper, 2001; Metropolitan Water District of Southern California Environmental Defense Fund, Source Reduction of Chlorinated Solvents-Textiles Manufacture. 1991; Toxics Use Reduction Institute TURA Data website, http://turadata.turi.org/