The Environmental Fate of Plasticizers

Butyl benzyl, diaUyl, di-n-butyl, diethyl, di-(2-ethylhexyl), dihexyl, diisobutyl, diisodecyl, diisononyl, diisooctyl, dimethyl, (h-n-octyl, dinonyl, ditridecyl, and diundecyl Di-(2-ethylhexyl) adipate, di-n-octyl adipate, di-(2-ethylhexyl) azelate, acetyl tributyl citrate, tricresyl phosphate, tri-(2-ethylhexyl) trimelhtate, di-(2-ethylhexyl) sebacate, and di-n-butyl seba-cate 

Environmental Protection Agency, EPA, maintains the Toxic Chemical Release Inventory. This database summarizes estimated chemical releases from industrial somees to air, water, land, and the subsurface by deep-well injection, and the transfer of materials to waste treatment sites in the U.S. 

Plastieizers are not elassified as Priority Pollutants, and henee there are no mandatory tracking requirements. Not all chemical companies are required to report to the U.S. EPA. Of the 23 plastieizers in Table 18.1, only three were in the TRl database (Table 18.2). The eombined estimated mass of di-n-butyl phthalate, di-(2-ethylhexyl) phthalate, and dimethyl phthalate released to air, water, and land (excluding deep-well injection) diu-ingthe period from 1997 through 1999 was about 1.6 metric tons. About 16.8 metric tons of these three phthalates were transferred off-site to treatment plants or other off-site loeations. In general, di-(2-ethylhexyl) phthalate appears to be the most widely used phthalate ester in North America.  

Phthalate Air Land Water Underground injection Off-site waste transfer 

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The environmental fate of plasticizers results from their chemical constitution. Most of them contain the ester group and thus the hydrolysis of ester bond is the main reaction in aqueous medium. According to Wolfe et al. [9] it appears that this reaction at pH 7 may be too slow and is negligible (the half-life time exceeds 100 days). 

The toxicity profile of the biocide is very important. Biocides that can be leached out of the plastic or bloom to the surface are an exposure risk to humans and the environment. Fish toxicity is also very important in pond and ditch liner applications. The environmental fate of the biocide must also be considered. It is desirable that the biocide is biodegradable and not persistent in the environment after it is done protecting the plastic. Extensive supporting documentation is required on the toxicity and environmental fate of any new product. 

Predicting the environmental fate and movement of plasticizers is currently hampered by a lack of information. There is also a lack of monitoring data to assess nonpoint sources. The aqueous solubility - a fundamental environmental property - of two of the 23 plasticizers has not been determined. As noted in this chapter, many properties such as Henry s Law constants, vapor pressure, organic carbon-water partition coefficients, octanol-water partition coefficients, bioconcentration factors, and photooxidation rates in the atmosphere were estimated using stractural analog models, empirical relationships based on other chemicals. Both biodegradation and adsorption appear to be the major mechanisms that control the fate of plasticizers released into the environment. Despite the... 

In this chapter we are going to explore whether a deeper investigation of the environmental fate and ecotoxicity of substances, released during the biodegradation of polymers and plastics, is possible by applying the principles of the Enropean Regulation 1907/2006, called REACH Registration, Evaluation, Anthorisation and Restriction of Chemicals [11]. 

Knowledge of the environmental fate and ecotoxicological profile of intermediates released during biodegradation would obviously enable a better characterisation of the environmental behaviour of the overall biodegradable polymer (or plastic), and would confirm and strengthen any conclusion on the absence of ecotoxicological effects, as already inferred from the bioassays prescribed by the aforementioned standards. 

The analysis of these materials is even more critical with increased interest in their environmental impact on ecological systems and human health. A number of frequently used additives, such as phthalate and adipate plasticizers have been identified as environmental pollutants, and the fate of these chemicals is the subject of ongoing studies. Concern over the total composition of plastics has increased the focus on the total life cycle of polymeric materials. Government attention to toxic substances has increased over the years through the US Toxic Substances Control Act (TSCA) and the REACH initiative in the EU. These regulations may prohibit or otherwise impact the exportability of the plastic goods or other products that come in contact with the plastics. This, coupled with increased consumer attention and disclosures of chemicals in consumer products, has increased the need for a more complete analysis of polymeric materials. Combustion of rubber... 

Abstract Phthalates are chemicals that have been used for over 80 years in large quantities due to their wide range of applications, mainly in the plastic industry. For many years, these compounds were not considered dangerous for humans due to their low toxicity shown in the preliminary studies and their low persistence. However, research conducted in recent years has evidenced their activity as endocrine disrupters, and they are now considered as emerging contaminants and included in the priority list of dangerous substances in the legislation of many countries. This chapter provides an overview on the properties, major uses, emission sources, environmental and human levels, current legislation, behavior and fate of phthalates, and their metabolites, with special emphasis on their toxicity and human exposure. 

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