Industries with most toxic substance

The Toxic Substances Control Act (TSCA) refers to "new chemicals" as those not on the TSCA Inventory of Chemical Substances which lists about 55,000 existing commercial chemicals. All new chemicals must enter EPA s premanufacture notification program (PMN) for review before manufacture. This program is the most complete record of development of new chemicals by U.S. industry over the past 2 1/2 years. To date over 1,000 notices have been submitted, many including confidential business information (CBI). Despite the CBI, it is possible to summarize EPA s experience with new chemical substances and to evaluate the PMN program and its impact on product innovation. That is essentially the aim of this paper. 

The identification and quantitation of potentially toxic substances in the environment requires the application of sophisticated analytical techniques. Ideally, these should exactly identify each of several hundred compounds present in very complex mixtures even though each species may have an environmental concentration of less than a part per billion. The most generally useful and widely employed analytical tool which meets these requirements is gas chromatography mass spectrometry (GCMS). In this paper, we will briefly review sample isolation methods which are used with GCMS and present two case studies on the organic compounds in industrial wastewaters and river systems which demonstrate these and other principles. 

Another development is due to the interest in polychlorodibenzofurans, spurred by their occurrence as environmental contaminants. Polychloro-phenols are manufactured in large amounts (150,000 tons per annum) and find a wide range of uses. The usual method of manufacture involves the hydrolysis of chlorobenzenes, and side reactions, favored by high temperature, can lead to the production of polychlorodibenzofurans and poly-chlorodibenzo-p-dioxins. The Seveso incident is well known." Polychloro-biphenyls are also widely used industrial chemicals, particularly in heat exchange systems, and their pyrolysis leads to the formation of polychloro-dibenzofurans. Polychlorodibenzofurans have also been detected in the fly ash and flue gases of incinerators and industrial heating plants. The most toxic of the polychlorodibenzofurans are 2,3,7,8-tetra-, 1,2,3,7,8-penta-, and 2,3,4,7,8-pentachlorodibenzofuran, and an extensive literature exists on the environmental pollution and the results of human exposure to these substances. A particularly tragic example of the latter occurred in 1968 in the Fukuoka prefecture of Japan after consumption of rice oil contaminated with a commercial polychlorobiphenyl. 

A list of 400 toxic substances may be found in the Federal Register, Volume 40, No. 23072, May 28, 1975. An abbreviated list may be obtained from Inorganic Syntheses, Vol. 18, p. xv, 1978. A current assessment of the hazards associated with a particular chemical is available in the most recent edition of Threshold Limit Values for Chemical Substances and Physical Agents in the Workroom Environment published by the American Conference of Governmental Industrial Hygienists. 

However, the cornerstone of US chemicals legislation is the Toxic Substances Control Act, which regulates most substances and most of the quantities, in particular industrial chemicals. In the following, the statutes and the more than 30 years of implementation of TSCA will be described and analysed. The investigation is limited to statutes with a general reach the parts of TSCA that address specific substance groups will not be dealt with.25... 

This chapter does not focus primarily on metal toxicity, although metals may be toxic and damage lung tissue, especially in particulate form and in industrial settings. For comprehensive coverage of this topic see Reference 1. This chapter deals with metal ion toxicity because it is via their ions that metals are presented as toxic substances to most of us. 

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