Classified areas

Table 9.18 Areas classified as requiring Zone 2 electrical equipment...

Safety Barriers. Figure 1 illustrates an application employing intrinsically safe electrical circuits for the demilitarization of ammunition. Three separate areas are required for this application - one area, classified as non-hazardous, to serve as the control and loading area a second area, classified as hazardous, where the actual demilitarization is accomplished and a third area, classified as non-hazardous, is required for the hydraulic pump due to the level of noise produced. 

Level I. Areas classified as class 100, critical areas, involve operations in which the sterilized product containers and closures are exposed to the environment. The most stringent quality standards are imposed upon areas directly over the filling/closing operation (in the filling suite). Curtains or shroud borders are attached to the perimeter of the HEPA filter housing to maintain the air quality of the critical area. This type of area includes the aseptic filling suites and the sterility test LAFH. The areas classified as level I are as follows ... 

If area classified hazardous, give division, group, etc.. . 

Another special feature of intrinsic safety - i - also results from its appropriateness for zone 0 applications. Hazardous areas classified as zone 0 are characteristic of the presence of an explosive gas atmosphere at a high probability, e.g. in the interior of a ventilated tank. Thus, special safety precautions are required. 

Ozone Classifications. The CAA sets a new classification structure for ozone nonattainment areas based on the severity of the nonattainment problem. For each area classified under this section, the attainment date is as expeditious as practicable but no later than the date in the following table. The classification scheme is as follows ... 

The designation/classification process for ozone was described in the Federal Register (4). For areas classified marginal to extreme, virtually all requirements are additive (e.g., a moderate area has to meet all marginal and moderate requirements, unless otherwise specified). The requirements reduce emissions of VOC and NO, which are precursors to ozone. This paper focuses on the NO,i requirements for major stationary sources. 

The CAA NO, provisions for RACT apply in all ozone nonattainment areas classified moderate or higher and throughout an ozone transport region. The RACT provisions do not apply to marginal ozone nonattainment areas except in ozone transport regions. 

Ozone non-attainment areas are classified according to the severity of the pollution problem (see Figure 19.2). These areas also have to achieve VOC reduction as determined by the non-attainment classification. A 15 percent VOC reduction in non-attainment areas, classified as moderate and above, was required by 1996. Also, Section 182(c)(2)(B) requires that non-attainment areas classified as serious and above follow with a 3 percent VOC reduction per year. ... 

New Source Review. In areas classified as nonattainment for any regulated pollutant, a different set of special rules restricts the construction of new sources. The basic thrust of these NSR rules is to require that such new sources install state-of-the-art control technology and also provide supplemental reductions in emissions from neighboring sources to more than offset whatever new emissions would result from the new source even after best controls are ntUized.The principal requirements are as follows ... 

Indicating pressure switches provide both pressure indication and the switehing function. Switches installed into areas classified as hazardous, should either be explosion proof or used to switch very low electronic signals within the restraints of code directives. 

When using certain gases, it is desirable to maintain them at a set temperature for reasons related to the process and for safety. To do this, there are a number of different types of chillers and heaters. Circulating temperature controllers, use a temperature controlled liquid that is circulated through clam shell t)q)e jackets or coils placed around the cylinder. This type of system can have the actual control unit in a remote location and can easily be used in areas classified as hazardous. Another t5q)e controls the temperature of the air that is circulated through the cabinet. The air either transfers to or absorbs heat from the cylinder. Also available to heat cylinders are electrical resistance t5q)e devices. Some of these electrical devices cannot be installed into areas classified as hazardous. 

Where necessary, areas classified into zones are marked with a specified EX sign at their points of entry... 

In the case of new major stationary sources, the states try to stay or come into attainment through the New Source Review (NSR) program. The NSR program, sometimes called preconstruction permitting, addresses emissions from new major stationary sources i.e., entire facilities or major modifications to existing facilities. Requirements depend on whether the facility is in a non-attainment area or is in a prevention of significant deterioration (PSD) area. Major sources for these areas must obtain a permit before any construction or modification is started. CAA defines a major VOC source as one that emits 9.1 Mg/year in an area classified as severe. ... 

The use of classified trucks in areas classified as hazardous due to risk of fire or explosion as defined in ANSI/NFPA 505, Powered Industrial Trucks... 

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