Testing existing chemicals

Testing existing chemicals that may present risks ... 

Citi, Chemicals Inspection and Testing Institute, eds.. Biodegradation and Bioaccumulation Data of Existing Chemicals Based on the CSCE Chemical... 

What is important to emphasize is that, given the range of known EDCs, their potential to act with more than one mechanism of action, and ability of some chemicals to mediate effects via mnltiple tissues, no single effective test exists for an endocrine disrnpter rather, a snite of approaches is reqnired to capture the spectrum of possible effects. 

Requires a federal inventory of existing chemicals in commerce, notification for hsting of new chemicals or new uses for existing chemicals, and can require testing of chemicals for toxicity prior to approval for listing. 

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... 

Another balance of factors within TSCA has to do with the risks and benefits of the far larger number of existing chemicals. E.H. Blair s contribution examines the problem of setting priorities for testing exsiting chemicals to assess their risks in a cost-effective procedure. 

Aside from the actions already initiated by EPA under Section 6 to restrict exposures to polychlorinated biphenyls and to chlorofluorocarbons in certain uses, no other actions have been taken against specific chemical substances, nor has an imminent hazard been identified for appropriate action. Less than a dozen proposed orders have been issued under Section 5(e) requesting further information to assess the risks of as many new substances. Perhaps 80 informal requests for further information on such substances have been made and satisfied voluntarily. Testing programs for a substantial number of existing substances have been started and more are planned. In addition, of course, the monumental task of creating an inventory of some 55,000 existing chemicals was completed. 

Blair, Etcyl H., A Framework of Consideration for Setting Priorities for the Testing of Chemical Substances," Workshop on the Control of Existing Chemicals, Ber1in, Germany, June, 1981. 

Second, EPA could issue rules under S 8(a) to require periodic reports concerning the commercial development of certain new substances once they enter production. Unlike SNUR s, S 8(a) requirements would not prevent companies from continuing their production and marketing activities. Rather, EPA would review information contained in the 8(a) reports, and then could pursue control actions under its other TSCA authorities for regulating existing chemicals (i.e. 4 test rules, or 6(a) "unreasonable risk" regulat ions). 

The goal of the Toxic Substances Control Act (TSCA) is to provide authority to regulate chemical substances which present an unreasonable risk of injury to health or the environment. An important feature of TSCA requires the administrator of the Environmental Protection Agency (EPA) to examine such data on existing chemicals and, when it is insufficient, to direct industry to conduct tests. 

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... 

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. 

As to existing chemicals, while much information has been collected, what is most important is realizing the need to be more selective and skillful in collecting and processing data. Section 8(e) has been a fertile source of information on substantial risks, but only recently has EPA recognized the need to respond to these risks. EPA s failure to use its authority to require industry to test selected chemicals is similarly... 

Many other OECD activities on hazard/risk assessment are undertaken within programs such as Existing Chemicals, New Chemicals, and Pesticides and Biocides, which deal with specific types of chemicals. The work on exposure assessment methods is undertaken by the Task Force on Environmental Exposure Assessment, consisting of experts. Most of the outcome of this work is published in the Series on Testing and Assessment or in Emission Scenario Documents, which are available at the OECD Web site (OECD 2006a). 

Work undertaken on a chemical in the OECD HPV Chemicals Program as a follow-up to conclusions and recommendations by SIAM is considered as post-SIDS work, see also Table 2.2. This can include national/regional exposure information gathering and assessment as well as testing of endpoints beyond SIDS to assess a concern identified by SIAM. The Task Force on Existing Chemicals monitors post-SIDS work and can take decisions related to further work to be carried out in OECD in a concerted manner. 

US-EPA classifies chemical substances as either existing chemicals or new chemicals. US-EPA repeatedly screens these chemicals and can require reporting or testing of those that may pose an environmental or human health hazard. US-EPA can ban the manufacture and import of those chemicals that pose an unreasonable risk. 

According to the Technical Guidance Document (TGD) for risk assessment of new and existing chemical substances (EC 2003), smdies conducted with human volunteers are strongly discouraged as they are problematic from an ethical point of view and results from such smdies should be used only in justified cases (e.g., tests which were conducted for the authorization of a medical product or when effects in already available human volunteer smdies with existing substances have been observed to be more severe than deduced from prior animal testing). However, the potential differences in sensitivity of human smdies and smdies in animals should be taken into account in the risk assessment, on a case-by-case basis. 

The OECD Guidehnes for the testing of chemicals are a collection of the most relevant internationally agreed testing methods used by government, industry, and independent laboratories to characterize potential hazards of new and existing chemical substances and chemical preparations/ mixtures. 

This series presents review articles pertaining to molecular systems which are of Interest due primarily to the presence of structural features or characteristics about which prior predictions can be made based on present knowledge of chemical theory. These molecules often test the outer limits of what can be prepared and studied with regard to theromodynamic stability and kinetic reactivity. Studies of such systems provide an excellent test for existing chemical theory and thus furnish perhaps the best opportunity for advancing the frontiers of chemical knowledge. 

REACH guidelines may require teratology testing for new and existing chemicals. This chapter discusses procedures to assess the need for teratology testing and the conduct and interpretation of teratology tests where required. 

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