Hazardous substance, definition

FDA. 1970. Food and Drug Administration. Part 191-Hazardous substances definitions and procedural and interpretive regulations. Carbon tetrachloride findings of fact and conclusions and final order regarding classification as banned hazardous substance. Federal Register. 35 13198-13205. 

Waste minimization generally considers all of the methods in the EPA hierarchy (except for disposal) appropriate to reduce the volume or quantity of waste requiring dispos (i.e., source reduction). The definition oi source reduction as applied in the Pollution Prevention Act, however, is any practice that reduces the amount of any hazardous substance, pollutant, or contaminant entering any waste stream... 

TLV-C is defined as the tlireshold limit concentration value ceiling that should not be c.xccedcd during any part of the working e.xposure. This ceiling limit places a definitive boundtiry on concentrations of toxic or otlicrwisc hazardous substances tliat should not be exceeded. 

In addition to hazardous substances, CERCLA addresses pollutants and contaminants, which are broadly defined to include any substance that is reasonably anticipated to cause illness or deformation in any organism. All three definitions specifically exclude petroleum and natural gas. 

The SFA requires the definition of respective substances, a comprehensive analysis of the system (i.e. boundaries), and it is always limited in its extent due to process properties and data availability. Within this chapter the implementation of SFA for tracing hazardous substances in international informal e-waste treatment has been proved to be a useful method. To assess the hazardous consequences and potential risks of the selected chemicals to humans and the environment caused by informal recycling activities in those regions, different models exist, from which four have been chosen according to their specific focus and various pros and cons. 

Petroleum, natural gas, and synthetic fuels are excluded from the definition of a hazardous substance, and the definitions of pollutants and contaminants under CERCLA this is known as the Petroleum Exclusion. Although the EPA has the authority to regulate the release or threatened release of a hazardous substance, pollutant, or contaminant, the release of petroleum, natural gas, and synthetic fuels from active or abandoned pits or other land disposal units is currently exempt from CERCLA. Such sites cannot use Superfund dollars for cleanup, nor can the EPA enforce an oil and gas operator, landowner, or other individual to clean up a release under CERCLA. Substances exempt include such materials as brine, crude oil, and refined products (i.e., gasoline and diesel fuel) and fractions. 

The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) gives a broader definition of hazardous substances, which includes the following ... 

Under the Department of Transportation (DOT) regulations, a hazardous material is any substance or material, including a hazardous substance and hazardous waste that is capable of posing an unreasonable risk to health, safety, and property when transported in commerce. DOT thus has broad authority to regulate the transportation of hazardous materials that, by definition, include hazardous substances as well as hazardous wastes. 

Besides the dangers originating from hazardous substances and the conflicting interests of the involved parties, the discussion surrounding chemicals policy is also characterised by problems of comprehension, e.g. between corporate practitioners and proponents of regulation theories and/or between experts and the public. We thus present some definitions at the start of this chapter, at least for the sake of improved terminological clarity ... 

Change one substance into another, which usually aids excretion or reduces toxicity One thousandth of a gram ATSDR definition - "An MRL is an estimate of the daily human exposure to a hazardous substance that is likely to be without appreciable risk of adverse noncancer health effects over a specified duration of exposure."... 

The definition of exempt waste requires further elaboration. Although this Report is concerned with classification of waste for purposes of disposal, NCRP recognizes that some materials that contain only low concentrations of regulated hazardous substances may have beneficial uses if they could be exempted from regulatory control as hazardous material. 

Given the definition of risk indexes (Rid in Equation 1.1 or 1.2 and assuming that risks from exposure to the different hazardous substances in waste are additive, waste classes are defined by the requirement on each waste class and associated disposal system that ... 

The system for classification and disposal of hazardous chemical waste under RCRA is neither comprehensive nor is it based strictly on considerations of risks posed by waste. As noted above, all hazardous chemical wastes are managed alike, regardless of hazard, and this policy extends to waste that contains only minuscule amounts of listed hazardous substances. In addition, many potentially important wastes that contain hazardous chemicals are excluded from the definition of hazardous waste and, thus, are not presently regulated under RCRA. The distinction between regulated and unregulated wastes is based primarily on the source of the waste, rather than its hazard. 

Allowing for exemption of waste materials that contain sufficiently small amounts of hazardous substances is a potentially important means of balancing the resources required to manage waste and the benefits in health risks averted. As a consequence of the discussion in Section 5.1, it is desirable that the definition of waste that can be exempted and, thus, managed as if it were nonhazardous should be risk-based. Furthermore, waste should be exempted based on the consideration that the associated risks should not exceed levels generally regarded as negligible. 

In many respects, the system for classifying and managing hazardous chemical waste under RCRA makes no distinction between highly hazardous waste and virtually innocuous waste that contains very low levels of hazardous substances. Furthermore, many wastes that contain hazardous chemicals, as well as radionuclides not regulated under AEA, are excluded from the definition of hazardous waste based on the source of the waste, even though the excluded wastes can be just as hazardous as other wastes that are deemed hazardous under RCRA. 

The basic framework for the waste classification system developed in this Report is depicted in Figure 6.1. Starting with the objectives that the classification system should apply to any waste that contains radionuclides or hazardous chemicals and that all such waste should be classified based on risks to the public posed by its hazardous constituents, the fundamental principle of the proposed system is that hazardous waste should be classified in relation to disposal systems (technologies) that are expected to be generally acceptable in protecting public health. This principle leads to the definitions of three classes of waste, and to quantification of the boundaries of the different waste classes based on considerations of risks that arise from different methods of disposal. The boundaries normally would be specified in terms of limits on concentrations of hazardous substances. At the present time, nearly all hazardous and nonhazardous wastes are intended for disposal in a near-surface facility or a geologic repository, and these are the two types of disposal systems assumed in classifying waste. The three waste classes and their relationship to acceptable disposal systems are described in more detail in Section 6.2. 

NCRP assumes that the risk from disposal of any hazardous substance in waste can be described by means of a dimensionless risk index. The risk index for the ith hazardous substance is defined as the calculated risk from disposal of that substance, based on an assumed exposure scenario, relative to a specified allowable risk for the assumed type of disposal system. Based on this definition, the risk index is written as ... 

The risk index in Equation 6.2 is expressed in terms of risk (i.e., the probability that an adverse response will occur during an individual s lifetime). This definition is consistent with the fundamental objective of developing a risk-based hazardous waste classification system. However, the use of health risk per se in calculating the risk index presents some difficulties because risk is not proportional to dose for substances that cause deterministic effects. For this type of substance, the risk is presumed to be zero at any dose below a nominal threshold. Since the allowable dose should always be less than the threshold in order to prevent the occurrence of adverse responses, expressing the risk index in terms of risk would result in an indeterminate value and, more importantly, a lack of distinction between doses near the nominal thresholds and lower doses of much less concern. For any hazardous substance, including carcinogens for which risk is assumed to be proportional to dose without threshold, it is generally useful to express the risk index as the ratio of a calculated dose [e.g., sieverts, mg (kg d)-1] to an allowable dose that corresponds to an allowable risk ... 

The risk index defined in Equation 6.1 (see Section 6.2.1) is intended to provide a measure of the potential risk that arises from disposal of any waste that contains hazardous substances. In Section 6.3, the general definition of the risk index is elaborated and recommendations on suitable approaches to calculating the risk index for individual hazardous substances are presented. For purposes of developing a comprehensive and risk-based waste classification system, a simple method of calculating the risk from disposal of mixtures of hazardous substances is needed. The method must take into account that the allowable concentrations of particular hazardous substances in waste of a given class generally will be lower when multiple substances are present than when only a single substance is present. Such a method is presented and discussed in this Section. 

Given the qualitative definitions of the three waste classes, the boundaries of the waste classes would be quantified based on explicit descriptions of how the definitions are related to risk. The boundaries would be expressed in terms of limits on amounts (concentrations) of individual hazardous substances, with specified rules for how to classify waste that contains mixtures of hazardous substances, such as the sum-of-fractions rule for mixtures of substances that induce stochastic effects. Specifically, waste would be classified as exempt if the risk that arises from disposal in a municipal/industrial landfill for nonhazardous waste does not exceed negligible (de minimis) levels. Use of a negligible risk to quantify limits on concentrations of hazardous substances in exempt waste is appropriate because the waste would be managed in all respects as if it were nonhazardous. Nonexempt waste would be classified as low-hazard if the risk that arises from disposal in a dedicated near-surface facility for hazardous wastes does not exceed acceptable (barely tolerable) levels. An essential condition of the definitions of exempt and low-hazard waste is that an acceptable (barely tolerable) risk must be substantially greater than a negligible risk. Waste would be classified as high-hazard if it would pose an unacceptable (de manifestis) risk when placed in a dedicated near-surface facility for hazardous wastes. 

Green chemistry is also known as environmentally benign chemistry, or sustainable chemistry. Perhaps the most widely accepted definition of green chemistry is the one offered by chemists Paul Anastas and John Warner, who defined green chemistry as the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances. 

There is no universally accepted definition of "risk assessment." Some define it narrowly to mean only the identification of a hazardous substance. Others interpret it to mean the full range of activities, including the risk-benefit analysis and the economic considerations used to make a regulatory decision. 

What is an OSHA Hazardous Chemical Under HCS, each manufacturer or importer had to determine the hazards of the chemicals it manufactured or imported. These were broken down into many different physical and health hazards. If a substance possessed any of these properties, it was, by definition, a hazardous chemical and therefore had to have an MSDS created for it, listing certain properties and hazards in a loosely specified form. Even if, after testing, it was determined that the chemical did not fall into any of these 23 categories but was listed in certain other references, the standard said that it was also hazardous, by definition. 

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