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Toxicity predictions Subject

Furthermore the binding of different co-activators influences the type of activity for several compounds. Although very critical for toxicity predictions, extensive and sufficient modeling studies on this subject are currently lacking. [Pg.339]

Successful predictive models in toxicology exist - however, they are of a rather local nature. Effects considered in toxicology can be caused by different mechanisms. Efforts to get away from a class perspective to one that is more consistent regarding modes of toxic action are still a subject of ongoing research. [Pg.512]

Hormesis will be a subject of steady and perhaps increasing interest, but whether and in what way it moves to the center of the policy stage for toxic substances is beyond anyone s predictive powers. [Pg.265]

More than 50,000 chemicals are currently listed in the Toxic Substance Control Act (TSCA) inventory, but physical-chemical properties are available for a relatively small percentage and biological endpoints for even less. The costs associated with thoroughly testing all chemicals are prohibitive, so models are needed to (1) predict the environmental effects of a new chemical, or (2) assess whether the chemical should be subject to a detailed testing regime (J ). Although models are available to... [Pg.148]

Chemical analyses which determine the types of substances present, are incorporated to provide information for predicting control approaches, atmospheric dispersion/-transformation, and potential toxicity of the stream. Finally, because prediction of hazard based on physical and chemical analyses alone is subject to many uncertainties, biological assay techniques are incorporated as a measure of the potential toxicity. The basic Level 1 analytical procedures are given in Table II. [Pg.34]

Since combustion is subject to many variables, tests for flame retardancy may not correctly predict flame resistance under unusual conditions. Thus, a disclaimer stating that flame retardancy tests do not predict performance in an actual fire must accompany all flame-retardant products. Flame retardants, like many organic compounds, may be toxic or may produce toxic gases when burned. Hence, care must be exercised when using fabrics or other polymers treated with flame retardants. [Pg.490]

Drug/Food interactions Theophylline elimination is increased (half-life shortened) by a low carbohydrate, high protein diet, and charcoal broiled beef (due to a high polycyclic carbon content). Conversely, elimination is decreased (prolonged half-life) by a high carbohydrate low protein diet. Food may alter the bioavailability and absorption pattern of certain sustained-release preparations. Some sustained-release preparations may be subject to rapid release of their contents when taken with food, resulting in toxicity. It appears that consistent administration in the fasting state allows predictability of effects. [Pg.738]

On the basis of the scientific literature alone, It Is not possible to predict whether any long-term effects would be asoclated with the small exposures used. However, evaluation of this toxicity literature and the Edgewood studies led this Committee to conclude that, at the doses and frequencies of phencyclidine used at Edgewood in a small number of test subjects, It is unlikely that detectable long-term or delayed effects have occurred or will occur. [Pg.13]

CR, a mild lacrimatory Irritant, manifests less acute toxicity than CN and CS. At low doses, it causes transient effects. There are a few studies on long-term health effects, including potential mutagenicity and teratogenicity. The available data are insufficient to predict long-term health effects. The small number of exposures and the small number of subjects exposed to CR at low doses at Edgewood make the occurrence of demonstrable effects In these subjects unlikely. [Pg.15]

Although DM has greater acute toxicity to the respiratory tract than CS and CN, Edgewood subjects appeared to recover shortly after exposure. Given the available information on DM and the short low-dose exposures, It Is Impossible to predict whether Edgewood subjects exposed to DM will suffer any longterm effects of the exposure. [Pg.210]

New chemical products not under the FDA or FIDRA are covered by the Toxic Substances Control Act (TSCA). If these chemicals are intended to become articles of commerce, they are subject only to submission to the EPA of a request for a Pre-Marketing Notice (PMN). The EPA has 90 days to respond to such a request and often, in the absence of extensive data, relies on structure-activity relationship (SAR) predictions. [Pg.254]

Even for established excipients, regulators will look carefully at their presence in new drug formulations because they are not necessarily inert materials and some have well-established activity and/or toxicity. Clinically relevant adverse reactions are known for well-known excipients and the subject is covered elsewhere in the published literature (2,20,75-81). Findings tend to be uncommon compared to the overall prevalence of adverse drug reactions and often involve hypersensitivity reactions that are not likely to be predicted by conventional toxicity studies. [Pg.31]

Subjecting all chemicals to all possible tests is logistically impossible, and the future of toxicity testing must lie in the development of techniques that will narrow the testing process so that highly toxic and relatively nontoxic compounds can be identified early and either banned or permitted unrestricted use without undue waste of time, funds, and human resources. These vital commodities could then be concentrated on compounds whose fate and effects are less predictable. [Pg.396]

This last equation forms the basis for the EPA s sediment quality guidelines that are used to assess the potential toxicity of contaminated sediments. The idea is to simply measure Cs and foe, look up K0w in a table, compute the predicted Cw, and compare this result to established water quality criteria for the protection of aquatic life or human life (e.g., carcinogenicity risk factors). The use of this simple equilibrium partitioning expression for this purpose is currently the subject of much debate among scientists as well as policy makers. [Pg.490]


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Subject Toxicity

Toxicity prediction

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