Classification of hazardous

Electrical apparatus for explosive gas atmospheres Classification of hazardous areas 5572/1994 BS EN 60079-10/1996 ... 

Classification of hazard areas according to the probability of a flammable concentration of vapour occurring (to BS 5345 Part 1)... 

Englehardt, J. D. (1993). Pollution Prevention Technologies A Review and Classification. of Hazardous Materials 35, 119-50. 

FPN No. 1) As a guide in determining when flammable gases are present continuously, for long periods, or under normal conditions, refer to. Recommended Practice for Classification of Locations for Electrical Installations of Petroleum Facilities, API RP 500-1991, Electrical Apparatus for Explosive Gas Atmospheres, Classifications of Hazardous Areas, lEC 79-10 and. Institute of Petroleum Area Classification Code for Petroleum Installations, IP 15. 

Classification of hazard areas according to the probability of a flammable concentration of vapour occurring (to BS 5345 Part 1) Zone 0 Area in which an explosive gas-air mixture is continuously present, or present for long periods Zone 1 Area in which an explosive gas-air mixture is likely to occur in normai operation Zone 2 Area in which an explosive gas-air mixture is not likely to occur in normal operation, and if it occurs will exist only for a short time Safe area By implication, an area that is not classified Zone 0, 1 or 2 is deemed to be a non-hazardous or safe area with respect to BS 5345 ... 

Hazardous waste identification To facilitate the proper identification and classification of hazardous waste, RCRA begins with hazardous waste identification procedures. 

The classification of hazardous locations involves the determination of four factors ... 

For complete definitions and classification of hazardous electrical environments, consult Article 500 of the NEC. 

Hazardous places are classified in terms of zones (divisions) on the basis of the frequency and duration of the occurrence of an explosive atmosphere (IEC 60079-10 200X, Classification of Hazardous Areas European Standard EN 50281-3 200X, Classification of Areas Where Combustible Dusts Are or May Be Present ). 

All personnel should have a detailed knowledge of UN Classification of hazardous or dangerous chemicals and other regulations pertaining to storage and transportation of explosives in order to reduce the inherent hazards associated with the explosives-related work. 

Classification of Hazardous Reactions Generated from the Reaction of... 

Classification of Hazardous Reactions Generated from the Reaction of Water with Water-Reactive Materials (from Refs 1,2,3 8t 5)... 

Second, waste that contains hazardous substances is classified based on considerations of health risks to the public that arise from waste disposal. The existing classification systems for radioactive and chemical wastes in the United States are not based primarily on considerations of health risks to the public. Rather, classification of hazardous wastes has been based primarily on the source of the waste or the presence of particular hazardous substances. The absence of risk-based waste classifications has had a number of undesirable ramifications ... 

Over the last several decades, separate classification systems have been developed for radioactive and hazardous chemical wastes based on a variety of considerations, the most prevalent being the source of the waste. These classification systems have served their intended purpose of facilitating development of health-protective strategies for waste management and disposal reasonably well. However, they have exhibited a number of shortcomings and undesirable ramifications, which indicate that a new approach to classification of hazardous wastes would be beneficial. 

This Report is concerned with classification of hazardous wastes. Wastes are materials deemed to have no further beneficial use to their present custodian, although these materials may be useful to others. Unless otherwise indicated, the term hazardous as used in this Report refers to the presence of radionuclides, hazardous chemicals, or both. This term also may refer to certain characteristics of materials that pose a hazard, such as ignitability, corrosivity, or reactivity. 

The primary purpose of this Report is to present NCRP s recommendations on classification of hazardous wastes. The Report is directed at a multidisciplinary audience with different levels of technical understanding in the fields of radiation and chemical risk assessment and radioactive and chemical waste management. Anew hazardous waste classification system is proposed that differs from the existing classification systems for radioactive and hazardous chemical wastes in two fundamental respects. First, hazardous waste would be classified based on considerations of health risks to the public that arise from disposal of waste. Hazardous waste would not be classified based, for example, on its source. Second, the classification system would apply to any hazardous waste, and separate classification systems for radioactive and hazardous chemical wastes would not be retained. In the proposed system, waste would be classified based only on its properties, and the same rules would apply in classifying all hazardous wastes. 

This Report is concerned with classification of hazardous waste for purposes of disposal. However, the principles and concepts embodied in the waste classification system could be applied in classifying hazardous materials for any other purpose. The classification system is intended to be applied to hazardous waste prior to disposal. It is not intended to be applied to screening or ranking of contaminated sites, including existing hazardous waste disposal sites, because these activities involve site-specific considerations that cannot be included in a generally applicable waste classification system. However, any wastes exhumed from contaminated sites that then require disposal would be included in the waste classification system. 

NCRP s recommendations on classification of hazardous wastes are intended to address deficiencies and inconsistencies in the separate systems for classification and disposal of radioactive and hazardous chemical wastes in the United States summarized previously. The most important of these include ... 

Each of these issues is addressed in presenting NCRP s recommendations on classification of hazardous waste in the following section. 

Waste classification systems are not transparent or defensible. There exist numerous classification systems for different wastes having a variety of bases and implementation rules that are not tied to any consistent set of principles. As a consequence, the overall classification of hazardous waste is not transparent to... 

The states of Washington and California have considered a classification of hazardous chemical waste based on risk and have developed a category of extremely hazardous waste (California, 1999 Mehlhaff et al., 1979 NAS/NRC, 1999b). However, the requirements for treatment and disposal of extremely hazardous waste differ little from those applied to other hazardous waste. Thus, the designation of a class of extremely hazardous waste based on relative hazard has had little effect on waste management and disposal. 

Under current EPA regulations, a chemical waste is either hazardous or it is not, and there is no further classification of hazardous chemical waste with respect to the degree of hazard. Some states have defined classes of hazardous chemical waste (e.g., extremely hazardous waste) but, in practice, the requirements on management and disposal of all hazardous wastes have resulted in essentially the same approaches being used regardless of hazard. When a hazardous chemical waste is mixed with a nonhazardous solid waste, the entire waste is classified as hazardous unless the former is a characteristically hazardous waste that does not contain any listed waste and mixing with the nonhazardous waste removes the hazardous characteristic. 

Classification of hazardous waste based on risk requires assumptions about allowable risks from exposure to hazardous substances. Therefore, an understanding of current approaches to risk management for radionuclides and hazardous chemicals, especially their differences and how they can be reconciled, is important in classifying waste. 

Fig. 6.2. Decision diagram for classification of hazardous waste using the risk index (RI).

This Section provides example applications of the recommended risk-based waste classification system to a variety of hazardous wastes to illustrate its implementation and potential ramifications. Disposal is the only disposition of waste considered in these examples. In Section 7.1.1, a general set of assumptions for assessing the appropriate classification of hazardous wastes is developed, including a variety of assumed exposure scenarios for inadvertent intruders at waste disposal sites and assumed negligible and acceptable risks or doses from exposure to radionuclides and hazardous chemicals. Subsequent sections apply the methodology to several example wastes. 

Despite the best efforts of pollution prevention and recycling programs, hazardous wastes are being, and will continue to be, generated. Classification of hazardous waste is necessary for cost-effective waste management. 

The most appropriate primary basis for classification of hazardous waste is the risk to human health posed by waste. Furthermore, the health risks of primary concern in classifying hazardous wastes are risks to the public that arise from waste disposal, since permanent disposal is the intended disposition of most waste materials having no further use to their present custodian. 

MEHLHAFF, L.C., COOK, T. and KNUDSON, J. (1979). A quantitative approach to classification of hazardous wastes, Solid Waste Manage. 21, 70-86. 

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