The report of CSB's combustible dust study also listed five recommendations for OSHA. This notice addresses the first of these recommendations:
``Issue a standard designed to prevent combustible dust fires and explosions in general industry. Base the standard on current National Fire Protection Association (NFPA) dust explosion standards (including NFPA 654 and NFPA 484), and include at least

The second CSB recommendation requested that OSHA revise its Hazard Communication Standard (HCS) (29 CFR 1910.1200) to clarify the coverage and requirements related to combustible dust. This recommendation is being addressed in a separate rulemaking.

The third and fourth CSB recommendations suggested that OSHA, respectively, communicate with the United Nations Economic Commission for Europe the need to amend the Globally Harmonized System to address combustible dust hazards, and provide combustible dustrelated training through the OSHA Training Institute. Both of these recommendations have been accomplished.

The fifth CSB recommendation suggested that OSHA initiate a Special Emphasis Program for Combustible Dust, to include an outreach program focused on the information in OSHA's Safety and Health Information Bulletin, Combustible Dust in Industry: Preventing and Mitigating the Effects of Fire and Explosions. The Agency went beyond CSB's recommendation and implemented a National Emphasis Program (NEP) to increase OSHA's enforcement activities throughout the country and to focus on specific industry groups that experienced either frequent combustible dust incidents or combustible dust incidents with catastrophic consequences. The NEP was launched on October 17, 2007, and is ongoing. It was revised in 2008 to more closely focus on sugar plants.

E. Congressional Response

Interest intensified in regulatory action during the months after the sugarplant incident in 2008. Employee unions expressed support for CSB's rulemaking recommendations. On May 1, 2008, the U.S. House of Representatives introduced a bill
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entitled H.R. 5522, Worker Protection Against Combustible Dust Explosions and Fires Act of 2008. This bill directed OSHA to issue an interim combustible dust rule and an amendment to the HCS in 90 days, and a final rule in 18 months. H.R. 5522 was passed by the House and referred to the Senate.

Two Congressional hearings were held on H.R. 5522. The first hearing was held by the House Committee on Education and Labor on March 12, 2008, and the second hearing was held by the Subcommittee on Employment and Workplace Safety of the Senate Housing, Education, Labor and Pensions Committee on July 29, 2008. Assistant Secretary of Labor Ed Foulke testified for OSHA at these hearings; also testifying were representatives of CSB, NFPA, and the Georgia sugar plant that sustained the 2008 explosion.

On February 4, 2009, H.R. 849, Worker Protection Against Combustible Dust Explosions and Fires Act of 2009, was introduced into the current session of Congress. The provisions of this resolution are the same as H.R. 5522.

F. Existing OSHA Standards

The Agency does not have a single, comprehensive standard that addresses combustible dust hazards across all industries. Current OSHA standards provide limited protection from dust hazards in two ways: First, certain standards address some dust hazards for specific industries. Among these standards are the following:

Second, some general industry standards address one or more of the elements that can contribute to dust explosions, such as ignition sources and dust accumulations, or the standards require the communication of information that employers and workers need to address dust hazards. Among these standards are:

As noted earlier, OSHA's existing standards for combustible dust do not provide a comprehensive set of requirements to fully address all of the prevention and mitigation methods specific to combustible dust hazards. Accordingly, some ignition sources are specifically covered (e.g., electrical installations, powered industrial trucks), while other ignition sources are not covered (e.g., mechanical sparks, friction, open flames). Additionally, OSHA standards address the accumulation of fugitive dust (i.e., dust that escapes from equipment or areas where it is normally present), but do not include measures that would prevent the escape of dust in the first place. Also, many builtin engineering controls (including the design of facilities, explosion venting, suppression systems, and explosion protection systems) are not addressed in the OSHA standards. OSHA is asking a series of questions about the need to address these areas in a new combustible dust standard to afford adequate and complete protection to workers.

G. Consensus and Industry Standards

NFPA issues a number of national consensus standards that address the hazards of combustible dust. For example, NFPA 654, Standard for the Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids, addresses the hazards of combustible dust in a general manner. Specific industries are excluded from NFPA 654, but are covered by other NFPA standards, including NFPA 61, Standard for the Prevention of Fires and Dust Explosions in Agricultural and Food Processing Facilities; NFPA 484, Standard for Combustible Metals; NFPA 655, Standard for Prevention of Sulfur Fires and Explosions; and NFPA 664, Standard for the Prevention of Fires and Explosions in Wood Processing and Woodworking Facilities.

These five NFPA combustible dust standards have mandatory secondary references to a large number of other standards. The 2006 edition of NFPA 654 mandates compliance with 36 other NFPA standards. These 36 secondary references, in turn, reference additional standards. In effect, no one standard comprehensively addresses the hazards of combustible dust, which may pose difficulties for some employers trying to develop programs to mitigate combustible dust hazards. In addition, the provisions of these five NFPA standards differ, which may add to these difficulties. Some elements of protection are addressed in some standards but not in others; other elements are addressed in different ways in the various standards. For example, NFPA 61, 484, and 654 contain provisions for drive belts, while NFPA 655 and 664 have no provisions directly addressing drive belts.

In addition to the NFPA standards listed above, NFPA issues a number of standards that cover the design and installation of protection systems specific to deflagration and explosion hazards, including combustible dust. Two of these standards are NFPA 68, Standard on Explosions Protection by Deflagration Venting, and NFPA 69, Standard on Explosion Prevention Systems. NFPA also has a series of standards that cover automatic fire suppression and alarm systems for a variety of facilities and hazards, but are not specific to combustible dust, deflagrations, or explosions.

A large majority of State and local jurisdictions in the United States have adopted the NFPA standards because both of the model fire codes used in this country (i.e., International Code Council's International Fire Code, and NFPA's Fire Code) make these NFPA standards mandatory. However, the 2006 report on CSB's combustible dust study indicates that enforcement of these fire codes at the State and local level is ``inconsistent and largely ineffective.'' For example, the 2008 sugarplant incident occurred in Georgia, a State having a fire code that mandated compliance with, among other combustible dust related consensus standards, NFPA 61, Standard for the Prevention of Fires and Dust Explosions in Agricultural and Food Processing Facilities.

NFPA standards are updated on a regular basis, usually every three years. In the Agency's experience, consensus standards incorporated by reference into OSHA rules quickly become out of date, making it difficult for employers to comply when the outofdate consensus standards become difficult to obtain. Furthermore, OSHA cannot legally update NFPA or other consensus standards used in its rules by referring to the ``current'' or ``most recent'' edition of the consensus standards.

Despite the aforementioned challenges with the application and enforcement of NFPA standards, the standards are used to a significant extent throughout industry, particularly by large companies, engineering consultants, and firms designing facilities with combustible dust hazards. Therefore, OSHA is asking for comment [[Page 54340]]
on how best to incorporate the provisions of the consensus standards. H. National Emphasis Program Analysis

OSHA analyzed the results of its Combustible Dust National Emphasis Program (NEP) to better understand where combustible dust hazards exist and where improvements may be needed to ensure that workers are protected from combustible dust hazards. Between November 1, 2007, and February 24, 2009, OSHA conducted 813 inspections under this NEP665 in States under Federal OSHA authority, and 148 in States having an OSHAapproved State Plan. OSHA cited employers for 3,662 violations.

Of the 665 Federal NEP inspections, 160 citations were issued under the General Duty Clause (GDC) for hazards related to combustible dust. Therefore, the rate of GDC usage for combustibledustrelated hazards in the NEP inspections was 24 percent during the time period noted above (These statistics were derived from the information available at the time this notice was developed; the numbers may change over time through the informal conference and settlement process.)

The 160 GDC violations referenced 32 different industry or consensus standards developed by 6 different standardsdeveloping organizations. The eleven most frequently referenced consensus standards were as follows, in descending order of frequency:

It has been necessary to cite the GDC extensively to address the various aspects of combustible dust hazards. GDC citations focused on each of the elements that could contribute to a dust fire or explosion, including containment or control of dust, isolation or control of ignition sources, and explosion venting or suppression systems. The following hazards were the most commonly cited GDC violations:

This list provides some indication of the areas in which current standards do not cover combustible dust hazards in general industry. Only the last two items on the list are administrative or operational in nature, involving maintenance, work practices, policies, and procedures. The other ten items involve engineering controls, such as fixed facilities or protection features built into the plant or the processing systems. These specific GDC violations point to areas that may be appropriate to cover in a prospective OSHA standard for combustible dust. Therefore, OSHA arranged the questions it is asking to solicit information separately for engineering controls and administrative controls.

The main finding of this NEP analysis is the unusually high rate of GDC use in combustible dust inspections (24 percent). Ordinarily, the GDC is used on a much more limited basis. For the same time period between November 1, 2007 and February 24, 2009, the 48,969 Federal OSHA inspections that were conducted outside the NEP yielded 1,736 GDC citations (a rate of 3.5 percent). Therefore, the GDC was used almost seven times as often for combustibledustrelated citations than for all other citations. This unusually high proportion suggests the need for a comprehensive OSHA standard.

I. Regulatory Issues

The CSB recommended that OSHA issue a standard to prevent combustible dust fires and explosions. The CSB determined that many tragic accidents in the past decade could have been avoided or minimized if employers had complied with applicable national consensus standards. OSHA recognizes that regulatory action needs to be considered as part of its overall approach to protecting workers from combustible dust hazards. The Agency already has made significant efforts to address the need for additional information and training on combustible dust hazards. Among these efforts are OSHA's SHIB, fact sheet, and poster; additional information provided on the Agency's Web site; outreach to employers; and specialized training for compliance officers. In addition, through the NEP, OSHA also enhanced compliance through strengthened enforcement of existing standards and citations under the General Duty Clause.

The existing regulatory regime is fragmented and incomplete. The Agency's analysis of the combustible dust NEP, above, shows that existing OSHA standards do not regulate important elements of combustible dust hazards. The consensus standards related to combustible dust are large, complex, numerous, and interrelated, which make it difficult for employers to comply with them. In addition, where these consensus standards have been adopted as part of State or local codes, available evidence shows that they are poorly enforced at the local and State levels.\18\ Therefore, OSHA has preliminarily concluded that national consensus standards alone, even when
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adopted by State or local governments, are insufficient to adequately protect workers from these hazards.
\18\ U.S. Chemical Safety and Hazard Investigation Board Investigation Report No. 2006H1, Combustible Dust Hazard Study; November 2006, page 68.

As noted earlier, combustible dust hazards are present in a wide range of industries. Many different materials, both organic and inorganic, can produce dust capable of fueling explosions. OSHA plans to evaluate affected industries to determine the most effective way to regulate the combustible dust hazards present in these industries. It may be appropriate for OSHA to treat specific industries differently, based at least in part on current national consensus standards.

OSHA must consider many factors in developing a comprehensive standard for combustible dust. Some of these factors relate directly to the characteristics of the hazard and the range of variables encountered in the workplace, which affect the combustibility or explosibility of dusts. For any dust materials having a specific chemical composition, the chance of a combustible dust deflagration depends on many variables, including:

Many more variables come into play for combustible dust incidents than for scenarios involving flammable gases, flammable liquids, or largersized flammable solids. The ignition of vaporair mixtures, especially at rest, is much more predictable and reproducible than the ignition of combustible dust. Consequently, some mitigation methods used to address combustible dust hazards are not straightforward. Prescriptive requirements may not be reasonable or effective in such a scenario.

Another factor involves whether and how to integrate current and future national consensus standards into a regulatory scheme. One means of doing so may be for OSHA to require compliance with various NFPA standards, rather than to develop a governmentunique standard. Some of the issues with this approach are discussed earlier in section I(G) of this notice. Another approach may be to reference NFPA standards as acceptable compliance options.

OSHA must also consider the interrelationship of a combustible dust standard and other OSHA standards that address different features of the hazard, for example, the hazard communication, electrical, grain handling, and other standards noted earlier in section I(F) of this notice.

The information currently available indicates that the risk of combustible dust explosions is considerable and that a single, comprehensive standard addressing all of these hazards will likely provide clarity for employers and increased safety for exposed workers. OSHA is requesting information and comment from the public to evaluate what regulatory action it should take to further address combustible dust hazards within the general industry standards.

II. Request for Data, Information, and Comments

OSHA is providing the following questions to facilitate the collection of needed information and to facilitate public comment on relevant issues. OSHA invites commenters to respond to any questions for which they have specific knowledge, data, or information, regardless of their involvement with combustible dust, e.g., employer, employee, consultant, researcher, fire or building code enforcement official. Commenters also are encouraged to address any aspect of combustible dust safety that they believe would assist the Agency in considering appropriate regulatory action on the matter. OSHA requests that commenters provide a detailed response to questions, including a rationale or reasoning for the position taken, rather than simply replying ``yes'' or ``no.'' Also, relevant data that may be useful to OSHA's deliberations, or that may assist it in conducting an analysis of the impacts of future Agency actions, should be submitted. To assess the costs, benefits, or feasibility of any possible regulatory intervention, the Agency needs specific quantitative information on various safety measures. Therefore, for those recommendations involving specific interventions, any data in terms of costs and benefits associated with the recommendation would be helpful. To assist it in analyzing comments, OSHA requests that commenters reference the question number to which they are responding.

A. Industry Background

OSHA is interested in determining the extent of combustible dust hazards. The following questions address the extent of the hazards, and provide a context in which to understand your answers to subsequent questions.

1. What business are you in? What NAICS industry or industries are you in?

2. How many employees do you have? How many are production employees? How many employees work in areas where combustible dusts are present? What types of jobs do they perform?

3. What is the area of your facility? What percentage of this area has combustible dusts normally present? What percentage is subject to possible fugitive dust accumulations?

4. What type or types of combustible dusts are present?

5. Would you expect other firms in your industry to have similar combustible dusts hazards or are the products or processes that generate combustible dust in your facility unusual for your industry? Why?

B. Definition of Combustible Dust

No single, universally accepted definition of combustible dust is available. Even among standards promulgated by the same standards developing organization, the definitions vary significantly. NFPA 654 and 655 define combustible dust in general terms without regard for particle size. This approach recognizes that factors such as particle shape, agglomeration, and other characteristics listed earlier in this notice, can affect explosibility. Other standards (such as NFPA 61, 484, and 664) define combustible dust in terms of a minimum particle size. The definition in previous editions of NFPA 654 (which may still be used in some areas of the country) was also sizebased.\19\ Furthermore, OSHA's grain standard uses a sizebased definition for ``fugitive grain dust.''
\19\ The 2006 edition of NFPA 654 explains in Annex section A.3.3.4 the reason that the previous sizebased definition is no longer used: ``Dusts traditionally have been defined as a material 420 [micro]m or smaller (capable of passing through a U.S. No. 40 standard sieve). Combustible particulates with an effective diameter of less than 420 [micro]m should be deemed to fulfill the criterion of the definition. However, flat plateletshaped particles, flakes, or particles of fibers with lengths that are large compared to their diameter usually do not pass through a 420 [micro]m sieve yet still pose a deflagration hazard.''

Many different materials may form combustible dust, and several laboratory tests are available to characterize them. Some of these tests help determine a dust's basic explosibility. Other tests yield results on the degree of
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explosibility; these tests are useful for designers of builtin protective features or systems. In some cases, the hazards of certain dusts are widely known (for example, wood dust). In these cases, basic testing to determine whether the dust is explosive may not be necessary. OSHA is interested in data on the extent to which different materials are, or may form, combustible dust.

6. Do you determine whether a dust is considered a combustible dust by reference to data, testing, or some other means? Please explain.

7. What additional tests do you conduct to determine the level of combustibility of a particular dust?

8. Do you have any dusts that you assume to be combustible, and, thus, preclude the need or expense of testing? If so, please indicate what type of dust.

9. Certain definitions, in particular those definitions based on particle size alone, would not cover some materials that can present an explosion hazard in certain situations. Accordingly, identify any dusts that can explode that would not be included in your definition. Would your definition include some dusts for which explosions are very rare or unknown? If so, which ones?

C. Hazard Recognition

The CSB report on its combustible dust hazard study, as well as the investigative reports of specific combustible dust incidents discussed above, show a pattern of employers and workers being either unaware of the hazards posed by combustible dust, or of the seriousness of the hazards. As a result, many workers were not adequately protected from these hazards. Employers who have recognized the hazards were made aware of them in a variety of ways. OSHA is interested in data on the contributions of inhouse experts, outside consultants, insurance representatives, and local or State code authorities in improving awareness of the hazard.

10. How did you become aware that you had combustible dust present in your facility?

11. Who is responsible for determining if a dust is combustible? What expertise do they have?

12. How do you determine if dust is combustible? Do you use published data, and if so, from what source? Do you sample dust for laboratory testing, and if so, how often? Do you rely on labels or data sheets, including MSDSs, developed by others? Do suppliers provide you with information related to combustible dust? Please explain.

13. To what extent do the local code authorities, insurance representatives, or other outside experts determine the presence of combustible dust in your facility?

D. Hazard Assessment

Hazard assessments are systematic approaches to evaluating a hazard and selecting control or mitigation methods. CSB's report on its combustible dust hazard study recommends hazard assessments as necessary for the mitigation of combustible dust hazards. It should be noted that NFPA 654 refers to a hazard assessment as a ``Process Hazard Analysis.'' In addition to information about how employers perform hazard assessments, OSHA is also interested in the extent to which experts (both external and onstaff) are involved in hazard assessments.

14. Do you conduct assessments of combustible dust hazards? How often? What assessment method do you use? Describe the information you use in performing the assessment, as well as the information the assessment yields and how you use this information.

15. On whom do you rely for technical assistance when performing the assessment? Inhouse staff, local/State authorities, insurance representatives, or consultants?

16. How do you decide when outside expertise or assistance is necessary? How do you assess the capability of outside experts?

17. Are your employees involved in the hazard assessment? Does their involvement improve the assessment? Does their involvement improve their understanding of the hazard and its mitigation? E. Hazard Communication and Training

OSHA's Hazard Communication Standard (HCS), 29 CFR 1910.1200, comprehensively addresses the evaluation of the potential hazards of chemicals and the communication of hazard information to workers. Regarding dusts and other particulates, as with all chemicals covered by the HCS, a hazard evaluation must be conducted, taking into consideration all discernible hazards, including explosibility. It is incumbent upon manufacturers and importers to provide information on the potential for, and control of, combustible dusts.

The HCS standard has three main components that are essential to the effective functioning of a program. First, chemical manufacturers and importers must review available scientific evidence concerning the physical and health hazards of the chemicals they produce or import to determine if they are hazardous. This procedure is called a hazard determination or hazard evaluation. Second, for every chemical found to be hazardous, the chemical manufacturer or importer must develop Material Safety Data Sheets (MSDSs) and container labels to be transmitted to downstream users of the chemicals. Employers are required to maintain an MSDS in the workplace for each hazardous chemical that they use. Third, all employers must develop a written hazard communication program and provide information and training to employees about the hazardous chemicals in their workplace.

Regarding combustible dusts, anticipated operations, uses, and downstream material processing that generate dusts should be considered normal conditions when using a substance. These conditions include operations and uses such as abrasive blasting, cutting, grinding, polishing, or crushing materials; conveying, mixing, sifting, or screening dry materials; and the buildup of dried residue from processing wet materials.

The HCS requires chemical manufacturers and importers to develop an MSDS for each hazardous chemical they produce or import. The following MSDS requirements are applicable to combustible dust hazards: Chemical and common names of the hazardous chemical and all ingredients determined to present a physical hazard, physical and chemical characteristics of the hazardous chemical, any generally applicable precautions for safe handling and use, any generally applicable control measures, date of MSDS preparation or last revision, and the name, address, and telephone number of the responsible party preparing the MSDS.

During its combustible dust study, CSB reviewed MSDSs of 140 known substances that produce combustible dusts, and found that information regarding potential combustible dust hazards was poorly or inadequately transmitted to employers and workers; according to this report, 41 percent of the MSDSs reviewed in the CSB study did not warn users about potential explosion hazards. Of the remaining 59 percent of MSDSs sampled, most of the information was not stated in a place or manner clearly recognized by employees, or not specific to hazards related to combustible dusts. The CSB concluded that many of the MSDSs did not identify the potential for combustible dust explosions that could reasonably have been anticipated during downstream material processing.

Training is also a critical component of any program to control combustible dust and prevent fires and explosions. Employees need to understand the
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hazards, how to prevent the hazards, and what to do in the event of a fire or explosion.

The following questions address MSDSs and training related to combustible dust hazards.

18. Do the MSDSs you develop or use identify the risks associated with combustible dust hazards? Do they list mitigation measures? Are you aware of MSDSs that should identify combustible dust as a hazard and do not? If so, please explain.

19. Do you communicate information on the risks of, and controls for, combustible dust hazards to your employees as a part of your hazard communication program?

20. Do you train your employees on the hazards of combustible dust and its mitigation? Do you also provide refresher training? What is covered in each type of training that you provide? How many of your employees receive each type of training that you provide? How many hours of training is provided and at what frequency (on hire, annually, as needed)? Who provides the training? What are their qualifications? Do you use standardized training materials (such as films, books, and computer classes)?

21. Do you have any means of determining if employees understand the training? Do you have any means of determining if employees are applying the training? If so, describe these means.

F. Consensus, Industry, and Insurance Standards

Under the OSH Act, OSHA must consider the provisions of national consensus standards, such as those promulgated by NFPA, in its rulemaking efforts. In addition to this mandate, OSHA may consider standards that are not developed using the consensus standards process when determining appropriate protective measures for employees. The following questions refer to these standards.

22. Do you follow the provisions in NFPA standards for combustible dust? If so, which standards? Is this use voluntary, or based on mandates by local authorities, insurance carriers, or other entities? Do you have any difficulty in using the NFPA standards because of conflicting definitions, varying requirements, secondary references to other standards, or any other reason? If so, describe these difficulties.

23. Do you use FM Global Property Loss Prevention Data Sheet 776, Prevention and Mitigation of Combustible Dust Explosions and Fires, as an aid in determining how to mitigate the hazards of combustible dust? Is this use voluntary or mandated by your insurance carrier?

24. Are there any other standards or guides you use to address the hazards of combustible dust? If so, please indicate which ones, or describe them.

G. State and Local Codes

NFPA standards carry the force of law when adopted by a jurisdiction (Federal, State, county, or municipal); these standards also can be mandated by an insurance company or other entity. In some cases, even when not mandated, employers comply with these standards (or portions of them) as a matter of policy. Many State fire codes contain mandatory references to NFPA's combustible dustrelated standards either directly, or by the adoption of a model fire code. The two model fire codes used in this country (i.e., International Code Council's International Fire Code and NFPA's Fire Code) both mandate compliance with NFPA's combustibledustrelated standards. Despite the existence of consensus and insurance standards, and State fire codes, major incidents continue to occur, as described earlier in this notice.

The CSB's 2006 report on its combustible dust hazard study concluded that State and local enforcement of NFPA standards was inadequate to protect workers. The reasons found include limited resources, insufficient training, and enforcement efforts that concentrate on facilities other than industrial facilities.

OSHA's National Emphasis Program for combustible dust has resulted in many employers abating combustible dust hazards in their facilities. Some employers voluntarily upgraded their facilities, procedures, and policies based on outreach and guidance material made available by a variety of organizations (including OSHA) or in response to the publicity surrounding major dust explosions. These efforts increased worker and employer awareness of the benefits of complying with NFPA standards. Nevertheless, it is difficult to project trends for hazards that result in infrequent, major incidents such as combustible dust explosions. Because of the variability of the many components required for a significant combustible dust explosion, facilities can operate for decades without an incident, yet suffer a catastrophic event after a slight change in conditions. The following questions address enforcement issues involving combustible dust.

25. Does the fire or building code (State, local, or other) in your area specifically address the hazards of combustible dust? If so, how?

26. Has your facility been inspected by State or local authorities? Is this a regular occurrence? If so, at what frequency? Were these inspections initiated by the authorities, or did you take the initiative to contact them? Did the inspections include combustible dust hazards? Did the inspection officials have expertise on combustible dust hazards? What action did you take as a result of State or local inspections?

27. Do you know if State or local enforcement efforts have been effective in controlling combustible dust hazards? If you have information on any studies of this issue other than the CSB's study (for example, studies conducted by insurance organizations, code authorities, trade associations, consultants, or unions), please provide information on them.

H. Engineering Controls

Various methods of controlling occupational hazards fall into a hierarchy in order of their effectiveness. A typical hierarchy (beginning with the most effective method) is:

Administrative controls include work practices, personnel scheduling, operational procedures, and equipment maintenance. Engineering controls are fixed measures that are built into a facility or processing equipment to either remove a hazard (i.e., preventing it from occurring) or to minimize the effects of an incident (after a fire or explosion has begun). OSHA believes that, for combustible dust hazards, these two types of engineering controls may belong at different levels in the hierarchy. Those engineering controls that prevent the occurrence of an incident, hereinafter referred to as ``primary engineering controls,'' belong where they are normally seen in the hierarchy; ahead of administrative controls. Those engineering controls that minimize deaths, injuries, or damage after a fire or explosion has begun, hereinafter referred to as ``secondary engineering controls,'' may be more appropriately placed in the hierarchy after administrative controls. Therefore, OSHA has grouped the questions in this section into two categories: (a) Primary engineering controls, and (b) secondary engineering controls.

Collectively, primary and secondary engineering controls often include features of building design, processing
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systems, ventilation systems, protective systems, and alarm systems. In NFPA 654, these provisions are not retroactive; that is, facilities, equipment, structures, or installations that existed or were approved prior to the standard becoming effective may remain as is. While retrofitting of most equipment is not mandated under this standard, it allows the authority having jurisdiction to require retrofitting of equipment or features in situations presenting an unacceptable degree of risk.

If OSHA were to incorporate provisions for engineering controls in a combustible dust standard, it would need to address whether any of these controls should be (1) retrofitted for all existing facilities immediately, (2) mandated after a specified date or period (i.e., a delayed effective date), or (3) required only for facilities built after a specified date or period (i.e., a ``grandfather'' clause). The Agency is, therefore, asking the following questions regarding engineering controls.

28. Do your facilit

FOR FURTHER INFORMATION CONTACT

Information regarding this ANPR is available from the following sources: