Defining hazards

Hazardous Wastes The U.S. EPA has defined hazardous waste in RCRA regulations, CFR Parts 260 and 261. A waste may be hazardous if it exhibits one or more of the following characteristics (1) ignitability, (2) corrosivity, (3) reactivity, and (4) toxicity. A detailed definition of these terms was first published in the Federal Register on May 19, 1980, pages 33, 121-122. A waste may be hazardous if listed in Appendix Wll. 

The U.S. Environmental Protection Agency, Office of Solid Waste Management Programs, defines hazardous waste as "wastes or combinations... 

The use of electrical equipment in hazardous areas is covered by British Standards BS 5345 and BS 5501. The code of practice, BS 5345, Part 1, defines hazardous areas as those where explosive gas-air mixtures are present, or may be expected to be present, in quantities such as to require special precautions for the construction and use of electrical apparatus. Non-hazardous areas are those where explosive gas-air mixtures are not expected to be present. 

In most cases, data that are obtained through theoretical approaches (literature, data bases, software programs) may not be sufficient for final plant design. Experimental work is usually required on various scales depending on the extent of reactivity. Therefore, the application of well designed experimental test methods is of prime importance to define hazardous conditions. Numerous test methods are available using a variety of sample sizes and conditions. 

Hazard is commonly defined as the potential to cause harm . A hazard can be defined as aproperty or situation that in particular circumstances could lead to harm (Smith et al., 1988). Risk is a more difficult concept to define. The term risk is used in everyday language to mean chance of disaster . When used in the process of risk assessment it has specific definitions, the most commonly accepted being The combination of the probability, or frequency, of occurrence of a defined hazard and the magnitude of the consequences of the occurrence (Smith et al., 1988). 

California criteria for defining hazardous wastes that are ignitable and reactive are identical to Federal criteria for hazardous wastes under RCRA defined at 40 CFR, Part 261. The California corrosivity criteria differ from the Federal criteria only in the addition of a pH test for nonaqueous wastes. 

Because each state has its own criteria for defining hazardous wastes, the plant manager of an industrial site having hazardous substances should contact the local state environmental protection agency for the details. 

Table 1 can be used as a guide to define hazardous wastes from textile plants. Besides the direct toxicity of substances like chlorinated hydrocarbons, organo-Hg compounds, or concentrated alkaline solutions, other parameters have been defined with regard to problems during biodegradation or accumulation in the sludge from CWWT. A particular situation is found with colored effluents, where limits for spectral absorption have been defined. While the toxicity of textile dyes is comparably low, these limits were derived from the visual aspect of the water released from a textile plant because they look unhealthy. ... 

Legislation on packaging and labelling of dangerous substances defines hazardous chemicals under the following categories ... 

Given the definition of solid waste described above, Section 1004(5) of RCRA (1976) then defines hazardous waste as follows ... 

Define hazards and hazardous of EUC and EUC control system for all reasonably foreseeable circumstances... 

Hazard is the likelihood that the known toxicity of a material will be exhibited under specific conditions of use. It follows that the toxicity of a material, ie, its potential to produce injury, is but one of many considerations to be taken into account in assessment procedures with respect to defining hazard. The following are equally important factors that need to be considered physicochemical properties of the material use pattern of the material and characteristics of the environment where the material is handled source of exposure, normal and accidental control measures used to regulate exposure the duration, magnitude, and frequency of exposure route of exposure and physical nature of exposure conditions, eg, gas, aerosol, or liquid population exposed and variability in exposure conditions and experience with exposed human populations. 

On the other hand, RCRA defines hazardous waste as a solid waste or combination of solid wastes [1,18,20,22], which because of its quantity, concentration, or physical, chemical or infectious characteristics may (a) cause, or significantly contribute to an increase in mortality or an increase in serious... 

It would appear to be worthwhile to support efforts to develop risk assessment approaches along the lines I have discussed rather than join a consensus saying that it cannot be done, or in supporting selecting mathematical models which arbitrarily define hazards and risks. 

Some organizations feel it is appropriate that only those processing units that meet defined hazards criteria participate in the process safety metrics systems. 

Subtitle C establishes the hazardous-waste management system, which includes defining hazardous. According to RCRA, solid waste is determined to be hazardous because its quantity, concentration, or characteristics (referring to ignitability, corrosivity, reactivity, or toxicity) may ... 

The EPA criteria defining hazardous and toxic waste were used as guidelines in this study. The EPA criterion for toxicity of wastes is based on an extraction procedure to identify toxic wastes likely to leach into the groundwater. The... 

Heavy metals reaching the soil remain present in the pedosphere for many years even after removing of the pollution sources and increased amounts of heavy metals in soils of urban areas have been reported (Chen et al., 1997 Pichtel et al., 1997). However, it is known that the severity of pollution not only depends by heavy metal total content in soil, but more by the amount of their mobile and bioavailable forms, which are generally controlled by the texture as well physicochemical properties of soils. Therefore, to define hazards and to propose treatments and eventually new more appropriate utilisation of soils in urban areas the speciation, geochemistry and behaviour of heavy metals in soil have to be investigated. 

The subject of risk assessment is complex. There have been many different terms used and it is important to appreciate alternative views on the scope of the subject and the definitions used in risk assessment. Bef( e examining principles it is first necessary to define hazard, harm and risk. 

In 1983 an important report [1] appeared which defined hazard and risk. It emanated from the United Kingdom s Royal Society, and resulted from a study group concerned with risk assessment for engineering and health risks. Definitions of hazard and risk were further elaborated by a Working Party of the United Kingdom s Institution of Chemical Engineers... 

The information used to classify a chemical substance as dangerous , either to health or the environment, can be used for hazard assessment, which can be combined with chemical exposure data to produce a risk assessment. Further information on toxicity or exposure may be needed to refine the risk assessment, before any necessary risk management action is taken to ban or restrict the use of the chemical. (See also chapter by Cowie and Richardson.) Defined hazard and risk assessment procedures may be used by regulatffls, or informal assessments based on practical experience can be undertaken by chemical users, either voluntarily or to fulfil statutory obligations. 

Part 173 of the regulations, among other things, defines hazardous materials for transportation purposes and prescribes certain requirements to be observed in preparing them for shipment by air, highway, rail or water, or any combination of these modes of transportation. 

The GHS defines hazard categories for many, but not all, chemical hazards. Immune system effects and neurotoxicity, for exam-... 

Wastes defined as hazardous under RCRA include characteristic and listed wastes. An RCRA-defined hazardous waste is a waste that appears on one of four lists (F list, K list, U list, or P list) or exhibits at least one of four characteristics (ignitability, corrosivity, reactivity, or toxicity). Criteria for identifying characteristic hazardous wastes are included in Title 40, CFR part 261, subpart C. Listed wastes from industrial sources are itemized in 40 CFR part 261, subpart D. Other regulations that are relevant to the technology include the requirement to characterize the waste for a hazardous waste generator (40 CFR part 262.11), the requirement to determine if the hazardous waste is restricted from land disposal [40 CFR 268.7(a)], requirements for on-site storage of waste for up to 90 days [40 CFR 262.34(a)], or 40 CFR 264.553 for storage of waste in a temporary unit for up to 1 year prior to disposal. 

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