Chronic toxicity definition

In the test guidelines for chronic toxicity (OPPTS 870.4100, 870.4300), the following definition is provided Chronic toxicity is the adverse effects occurring as a result of the repeated daily exposure of experimental animals to a chemical by the oral, dermal, or inhalation routes of exposure. The guidelines request an exposure period of at least 12 months. The preferred species is the rat. 

Dose In the context of chemicals, the temi dose means the amount, quantity, or portion of the chemical exposed to or applied to the target (e.g., a human being). It may also refer to a consistent measure used in toxicological testing to determine acute and chronic toxicities. An alternate definition is die amount of ionizing radiation energy absorbed per unit mass of irradiated material at a specific location, such as a part of die human body, measured in REMS, or an inanimate body, measured in rads. 

Obviously, acute or chronic toxicity is not an issue with the use of C02. Similarly, the ecological impact of carbon dioxide is negligible when used as a solvent, and C02 is—by definition—not regulated as a VOC. The application of C02 as a solvent in chemical synthesis would not generate any additional carbon dioxide and therefore would not contribute to greenhouse gas emission. Even for large-scale applications, no toxic or environmental risk would arise in case of any accidental contamination of the immediate environment with the solvent C02 if sufficient ventilation is provided. 

US Consumer Product Safety Commission (CPSC) (1992) Labeling requirements for art materials presenting chronic hazards guidelines for determining chronic toxicity of products subject to the FHSA supplementary definition of toxic under the Federal Hazardous Substances Act final rules. Federal Register 57 46626—46674 (1992). 

In the proposed Health Effects Test Standards for Toxic Substances Control Act Test Rules by the EPA (6), "chronic effects" was defined as ...disease processes which have a long latency period for development, result from long-term exposure, are long-term illnesses, or combinations of these factors." But ambiguity still exists for instance, how long is "long-term" The reason for the absence of a clear-cut definition for chronic toxicity is the complexity of events... 

The chronic toxicity/carcinogenicity studies were designed as definitive studies to address the issue of safety. The experimental design involved utero exposure of rats and the use of weanling mice. Only certified batches of color from the various suppliers were used. Two laboratories were selected following an extensive evaluation of the facilities available at that time. 

CAS 26447-10-9 EINECS/ELINCS 247-710-9 Synonyms Benzenesulfonic acid, dimethyl-, ammonium salt Definition Ammonium salt of ring sulfonated mixed xylene isomers Empirical C HioOsS H,N Properties Sol. in water m.w. 203.26 anionic Toxicology Chronic toxicity or skin effects are not known narcotic in high doses TSCA listed Precaution Flamm. 

Another important definition and terminology is the so-called application factor , which is applied for converting data from one exposure period or end point to another, e.g. from an acute EC50 (measured) to a chronic NOEC (predicted). For surfactants, application factors from 10 to 1000 are generally used when missing data for chronic toxicity have to be derived from acute toxicity tests. The stringency of the acute test influences the dimension of the application factor. 

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