Priority Testing List

The ITC was formed pursuant to TSCA 4(e), which established a committee to make recommendations to the EPA for prioritizing chemicals for testing. The ITC meets every other month, and each May and November publishes a report listing its recommendations for testing. In its reports, the ITC lists chemicals that it recommends considering for 4 test rules, and those it designates for 4 test rules, and this combined list of chemicals is called the Priority Testing List. ... 

Other TSCA information gathering requirements are triggered by a chemical s appearance on the Priority Testing List. The Preliminary Assessment Information Reporting (PAIR) regulations mandate that EPA require manufacturers and importers to submit PAIR information on chemicals that the ITC recommends for consideration. The PAIR rule requires a quick and dirty collection of readily obtainable information on a chemical s use and properties. Similarly, the 8(d) health and safety study regulations require... 

It is worth watching daily Federal Registers that report on issuance of the ITC s Priority Testing List to see what chemicals may ultimately be subject to a 4 Test Rule. It certainly is preferable to submit data voluntarily than to be subject to a PAIR or 8(d) rule, with their associated penalties for violation. 

This study was undertaken to test the ability of our previous molecular connectivity models to accurately predict the soil sorption coefficients, bioconcentration factors, and acute toxicities in fish of polycyclic aromatic hydrocarbons (PAHs), alkylbenzenes, alkenylbenzenes, chlorobenzenes, polychlorinated biphenyls, chlorinated alkanes and alkenes, heterocyclic arid substituted PAHs, and halogenated phenols. Tests performed on large groups of such compounds clearly demonstrate that these simple nonempirical models accurately predict the soil sorption coefficients, bioconcentration factors, and acute toxicities in fish of the above compounds. Moreover, they outperform traditional empirical models based on 1-octanol/ water partition coefficients or water solubilities in accuracy, speed, and range of applicability. These results show that the molecular connectivity models are a very accurate predictive tool for the soil sorption coefficients, bioconcentration factors, and acute toxicities in fish of a wide range of organic chemicals and that it can be confidently used to rank potentially hazardous chemicals and thus to create a priority testing list. ... 

TABOR At the USEPA Workshop at Palo Alto, California, in July 1984 [see chapter 2 of this book], it was suggested that every one of the six isolation protocols recommended would be tested with surrogate compounds to validate the procedures, and Dave Brusick of Litton Bionetics and some of the other biologists in the group were talking about lists of compounds on the priority pollutant list and others to reflect compounds with and without known mutagenic activity. 

Section 4 of TSCA requires manufacturers, importers, and processors of certain chemical substances and mixtures to conduct testing on the health and environmental effects of chemical substances and mixtures, unless they qualify for an exemption.32 Testing requirements cover existing chemicals that are both individual substances and mixtures. New chemicals are not covered, since they are addressed in the PMN process. EPA has established a Master Testing List that lays out testing priorities, based on risk and exposure potential. 

Chemical substances, mixtures, or in some instances, categories of substances, that have been or are subject to PAIR reporting are identified in 40 C.F.R. 712.30. The list is expanded in two ways. Chemicals identified by the ITC in its biannual recommendations of chemicals for priority testing under TSCA 4 are required to be added to the PAIR list. In addition to reacting to ITC recommendation or designation of priority testing chemicals, EPA may... 

EPA. 1991. Twenty-seventh report of the Interagency Testing Committee to the administrator receipt of report and request for comments regarding priority list of chemicals. U.S. Environmental Protection Agency. Federal Register 56(44) 9534. 

This article describes the strategy on endocrine-disrupting substances issued by the European Commission last December, and details why its short-term goal to compile a priority list of chemicals for research and testing has been attacked by industry, environmentalists and scientists alike. 

E.H. Hurst s overview introduced several themes pursued by other chemical industry speakers. The Dow Chemical Company s E.H. Blair analyzed the problem of setting priorities for testing the 55,000 existing chemicals listed in the TSCA inventory for their effects on health and the environment. Resources for such testing are not unlimited. A systematic classification was made of these substances by production volume. The 9.5% of these substances which account for 99.9% of reported production were divided further into categories such as organic, inorganic, and polymeric. 

A seeond milestone was a letter by the PDG in May 1992 asking for further candidates, beyond excipients. Responses to that inquiry focused primarily on tests and assays. Replies were ranked by order of priority. The priority of excipients was expanded to the top 25, based upon further analysis of responses. The lists of combined assignments and priorities for pharmacopeial harmonization appeared in the forum publieations of the pharmacopeias [12,13]. 

The short-term actions include (1) establishment of a priority list of substances for further evaluation of their role in endocrine disruption monitoring levels of suspect chemicals in food and the environment (2) identification of vulnerable groups of people (such as children) who need to be given special consideration (3) establishment of an international network to enable information exchange and coordination of research and testing and (4) communication with the public and continuing consultation with stakeholders. 

In Figs. 8-10 one can see that the distribution of average potency, selectivity, and average efficacy/toxicity ratio is exactly as one would desire. One can conclude that list 1, the highest priority list, contains the most efficacious compounds based on the degree of testing performed so far. 

Petrasek et al. (1983) spiked the influent of an activated sludge plant with 50 /tg/liter of 22 organic compounds from the EPA list of priority pollutants. Polychlorinated phenols and biphenyls, phenols, phthalates, and PAHs were tested, with average removal rates of 97%. However, higher concentrations can destabilize an activated sludge system. The presence of cyanide, pentachlorophenol, 1,2-dichloropropane,acrylonitrile, phenolics, and ammonia can cause instability in the operation of activated sludge plants (Allsop et al., 1990). 

With so many chemicals in existence, the USEPA has had to set priorities for testing chemicals. First, low-volume chemicals, which are produced or imported at a rate of less than 10,000 pounds per year, were excluded. Approximately 25,000 chemicals are in this category. Second, polymers, which typically are not toxic, were dropped from the list, which left approximately 15,000 nonpolymer chemicals produced or imported in quantities from 10,000 pounds per year up to 1 million pounds per year. As a result, the USEPA has focused its testing on the 3000 to 4000 high-production-volume (HPV) and nonpolymer chemicals (USEPA, 1998b). 

The acute toxicity of phthalates is very low, exhibiting symptoms of somnolence and dyspnea in test animals only at high doses. Some of these substances are listed as U.S. EPA priority pollutants. 

GC/MS analysis is a positive confirmatory test that identifies the compounds based on their characteristic ions. Table 2.25.1 lists the characteristic ions for some commonly occurring phthalates, which have been hsted as U.S. EPA priority pollutants. 

Tri-o-cresyl phosphate, not classified as a pesticide, is the only organophosphate for which testing and a final report were to have been completed in 1986. One of the TOCP studies under the auspices of CDC/NIOSH, and with an A completion priority, was a reproductive/developmental toxicity study. However, it is unclear from the TOCP listings (ref. 172a, Table 23) whether either the reproductive study or one of the neurologic/behavioral studies for TOCP was completed and reported in 1986. 

The CWA has established discharge requirements for 129 individual toxic pollutants (VOCs, pesticides, metals and corrosives), known as priority pollutants, and conventional pollutants for 34 industrial categories (EPA, 1998b). Appendix 2 lists these pollutants, which are either individual chemicals or groups of chemicals of a similar nature. Aquatic toxicity testing and temperature measurements also often included into NPDES permits. 

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