Existing chemicals evaluation

Zeeman M, Auer CM, Clements RG, Nabholz JV, Boethling RS (1995) US EPA regulatory perspectives on the use of QSAR for new and existing chemical evaluations. SAR QSAR in Environ Res 3(3) 179... 

In order to achieve that an environmental fate model is successfully applied in a screening level risk assessment and ultimately incorporated into the decisionmaking tools, the model should have computational efficiency and modest data input. Moreover, the model should incorporate all relevant compartments and all sources of contamination and should consider the most important mechanisms of fate and transport. Although spatial models describe the environment more accurately, such models are difficult to apply because they require a large amount of input data (e.g., detailed terrain parameters, meteorological data, turbulence characteristics and other related parameters). Therefore, MCMs are more practical, especially for long-term environmental impact evaluation, because of their modest data requirements and relatively simple yet comprehensive model structure. In addition, MCMs are also widely used for the comparative risk assessment of new and existing chemicals [28-33]. 

In what is being called the most far-reaching overhaul of European Union environmental policy ever, the European Commission released a draft policy proposal on May 7 that, if enacted, would require virtually all manufacturers of chemicals to provide risk assessments and other information regarding products they sell or ship into the EU. Chemicals would also have to be registered with the EC and many downstream users of products that contain chemical entities would have to file paperwork as well. The Registration, Evaluation and Authorisation of Chemicals, or REACH, proposal would apply to approximately 30,000 new and existing chemicals, and test data would have to be developed on some 5000 specific chemical entities, many of which have been commonly used for decades. EUROPEAN COMMISSION... 

Section 4 of TSCA authorizes EPA to require manufacturers or processors to test specified existing chemical substances when available data and experience are insufficient to evaluate their health and... 

Regulation of New As Well As Existing Chemicals. An evaluation of TSCA s impact would differ from that of most environmental statutes in that the former purports to regulate new as well as existing chemicals. The objective of the premanufacturing notification (PMN) system under section 5 is to permit EPA to make a reasoned evaluation of new chemicals ... 

In this paper I have tried to show that measurement of health benefits attributable to TSCA is not feasible. I hope that in doing so I have not belabored the obvious. For new chemicals and for most existing chemicals, prospective evaluation of health benefits to be achieved by various exposure controls will have to be based on extrapolation from microbial and animal data. However, while such extrapolation may be useful in a qualitative sense, quantitative risk assessment techniques involve considerable uncertainty, and in any case have not been developed for chronic effects other than cancer. 

While participating in the European Union programme on risk assessment of existing chemicals, Euro Chlor (representing all major European chlorine producers), recognised the need to carry out a detailed risk evaluation on chemicals linked to the production of chlorine. In view of concerns about specific risks of organohalogen compounds to the marine environment as a sink for all watercourses, Euro Chlor focused on this environmental compartment, with emphasis on the North Sea. This sea area has been extensively studied and is controlled by the Oslo and Paris Convention for the Prevention of Marine Pollution (OSPARCOM). For a series of chemicals on lists of concern adopted by the North Sea Conference (1990), risk assessments are being carried out to demonstrate their variable environmental profiles. 

Environment Canada (2007) Existing substances evaluation. Substance profile for the challenge. Decamethylcyclopentasiloxane (D5). Chemical Abstracts Service Registry Number 541-02-6. http //www.ec.gc.ca/substances/ese/eng/challenge/batch2/batch2 541-02-6.cfm... 

The Concise International Chemical Assessment Documents (CICADs) (see Figure 2.3) are similar to the EHC documents in providing internationally accepted reviews on the effects on human health and the environment of chemicals or combinations of chemicals. They aim to characterize the hazard and dose-response of exposure to chemicals and to provide examples of exposure estimation and risk characterizations for application at the national or local level. They summarize the information considered critical for risk characterization in sufficient detail to allow independent assessment, but are concise, i.e., not repeating all the information available on a particular chemical. For more detail, readers of individual CICADs are referred to the original source document for the CICAD (either a national or regional chemical evaluation document) or an existing EHC (chemicals series). 

International Uniform ChemicaL Information Database (lUCLID) is the basic tool for data collection and evaluation within the EU risk assessment program for existing substances and has also been accepted by the OECD as the data exchange tool under the OECD Existing Chemicals Program (see Section 2.4.1.6 for details). 

The Registration, Evaluation, Authorisation and Restriction of Chemical substances (REACH) regulations came into force on June 1, 2007. At that time, it was estimated that there were approximately 100,000 existing chemicals, of which approximately 30,000 were marketed in volumes at or above 1 tonne per year. For these 30,000 substances, a registration dossier must be submitted. The registration requirements depend on the tonnage thresholds, as follows ... 

As can be seen from the Global Reactive Chemicals Standard, all existing chemical processes will have a Reactive Chemicals/Process Hazard Analysis review on a predefined periodic basis. In addition, every new plant Production Leader should review their process with the Reactive Chemicals Committee within 90 days of assuming responsibility for a pilot or production plant. Prior to the review, the Leader should acquire training on the chemistry and processes that they are working with. This should include an evaluation of raw materials, processes, products and waste to understand any potential reactive chemical hazards. They should review and be prepared to answer questions from the completed and updated RC/PHA protocol questionnaire as well as other relevant materials in their plant Process Safety Folder, such as F EI, CEI, etc. The review should cover all auxiliary operations to the process such as raw material and product storage drum, tank car and truck loading. 

For example, once implemented, the European Commission s new chemicals policy REACH (Registration, Evaluation and Authorization of Chemicals) -endorsed in 2003 - would require manufacturers and importers of over one ton per year of any chemical substance to gather information on the properties, hazards, and use of that substance, and submit the data to the European Chemicals Agency. The Agency would then determine if the chemical substance needed to be further regulated, restricted, or banned from use. It is estimated that about 30,000 existing chemicals produced in or imported into Europe would be subject to REACH. Key objectives of the European Commission s initiative on the reformulation of chemicals policy are to raise human and environmental safety levels as well as to simplify and standardize the current legislation. 

SimpleBox was created as a research tool in environmental risk assessment. Simple-Box (Brandes et al. 1996) is implemented in the regulatory European Union System for the Evaluation of Substances (EUSES) models (Vermeire et al. 1997) that are used for risk assessment of new and existing chemicals. Dedicated SimpleBox 1.0 applications have been used for integrating environmental quality criteria for air, water, and soil in The Netherlands. Spreadsheet versions of SimpleBox 2.0 are used for multi-media chemical fate modeling by scientists at universities and research institutes in various countries. SimpleBox models exposure concentrations in the environmental media. In addition to exposure concentrations, SimpleBox provides output at the level of toxic pressure on ecosystems by calculating potentially affected fractions (PAF) on the basis of species sensitivity distribution (SSD) calculus (see Chapter 4). 

The TSCA became law on October 11,1976 and came into effect on January 1,1977, except Section 4 (f) which took effect 2 years later.29 A major objective of TSCA is to characterize and evaluate the risks posed by a chemical to humans and the environment before the chemical is introduced into commerce. The Act authorized the U.S. EPA to secure information on all new and existing chemical substances. The Act also gave the EPA the authority to control any of the substances that were... 

Section 5 of TSCA regulates the manufacture or import a new chemical substance for commercial purposes. Under this section, EPA requires notice before manufacture or importation of nonexempt substances. They then evaluate whether the chemical substance poses a threat to human health or the environment. This notice is called a PMN and must be submitted at least 90 days prior to the activity.34 Manufacturers must also submit information on significant new uses of existing chemicals to EPA for its review. After its review of the PMN or Significant New Use information, EPA may limit, restrict, or prohibit the manufacture, use, distribution, or disposal of the chemical substance. 

Two screening reproduction toxicity study protocols were prepared by the OECD for initial evaluation of existing chemicals, especially of existing high production volume chemicals but also for initial exploratory tests at an early stage of assessing the toxicological properties of new chemicals or chemicals of concern. 

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