AUTHORITY HAVING JURISDICTION: The organization, political subdivision, office, or individual charged with the responsibility of administering and enforcing the provisions of this standard.
BUILDINGS: Structures, usually enclosed by walls and a roof, constructed to provide support or shelter for an intended occupancy .
DESIGN STRENGTH: The product of the nominal strength and a resistance factor.
ESSENTIAL FACILITIES: Buildings and other structures that are intended to remain operational in the event of extreme environmental loading from flood, wind, snow, or earthquakes.
FACTORED LOAD: The product of the nominal load and a load factor.
HIGHLY TOXIC SUBSTANCE: As defined in 29 CFR 1910.1200 Appendix A with Amendments as of February 1, 2000.
IMPORTANCE FACTOR: A factor that accounts for the degree of risk to human life, health, and welfare associated with damage to property or loss of use or functionality.
LIMIT STATE: A condition beyond which a structure or member becomes unfit for service and is judged either to be no longer useful for its intended function (serviceability limit state) or to be unsafe (strength limit state).
LOAD EFFECTS: Forces and deformations produced in structural members by the applied loads.
LOAD FACTOR: A factor that accounts for deviations of the actual load from the nominal load, for uncertainties in the analysis that transform the load into a load effect, and for the probability that more than one extreme load will occur simultaneously.
LOADS: Forces or other actions that result from the weight of all building materials, occupants and their possessions, environmental effects, differential movement, and restrained dimensional changes. Permanent loads are loads in which variations over time are rare or of small magnitude. All other loads are variable loads (see also "nominal loads").
NOMINAL LOADS: The magnitudes of the loads specified in this standard for dead, live, soil, wind, snow, rain, flood, and earthquake.
NOMINAL STRENGTH: The capacity of a structure or member to resist the effects of loads, as determined by computations using specified material strengths and dimensions and formulas derived from accepted principles of structural mechanics or by field tests or laboratory tests of scaled models, allowing for modeling effects and differences between laboratory and field conditions.
OCCUPANCY: The purpose for which a building or other structure, or part thereof, is used or intended to be used.
OTHER STRUCTURES: Structures, other than buildings, for which loads are specified in this standard.
P-DELTA EFFECT: The second order effect on shears and moments of frame members induced by axial loads on a laterally displaced building frame.
RESISTANCE FACTOR: A factor that accounts for deviations of the actual strength from the nominal strength and the manner and consequences of failure ( also called "strength reduction factor").
RISK CATEGORY: A categorization of buildings and other structures for determination of flood, snow, ice, and earthquake loads based on the risk associated with unacceptable performance. See Table 1.5-1.
STRENGTH DESIGN: A method of proportioning structural members such that the computed forces produced in the members by the factored loads do not exceed the member design strength (also called "load and resistance factor design").
TEMPORARY FACILITIES: Buildings or other structures that are to be in service for a limited time and have a limited exposure period for environmental loadings.
TOXIC SUBSTANCE: As defined in 29 CFR 1910.1200 Appendix A with Amendments as of February 1, 2000.
|Use or Occupancy of Buildings and Structures||Risk Category|
|Buildings and other structures that represent low risk to human life in the event of failure.||I|
|All buildings and other structures except those listed in Risk Categories I, III, and IV.||II|
|Buildings and other structures, the failure of which could pose a substantial risk to human life.
Buildings and other structures, not included in Risk Category IV, with potential to cause a substantial economic impact and/or mass disruption of day-to-day civilian life in the event of failure.
Buildings and other structures not included in Risk Category IV (including, but not limited to, facilities that manufacture, process , handle,store, use, or dispose of such substances as hazardous fuels, hazardous chemicals, hazardous waste, or explosives) containing toxic or explosive substances where the quantity of the material exceeds a threshold quantity established by the authority having jurisdiction and is sufficient to pose a threat to the public if released.a
|Buildings and other structures designated as essential facilities.
Buildings and other structures, the failure of which could pose a substantial hazard to the community.
Buildings and other structures (including, but not limited to, facilities that manufacture, process , handle, store, use, or dispose of such substances as hazardous fuels, hazardous chemicals , or hazardous waste) containing sufficient quantities of highly toxic substances where the quantity of the material exceeds a threshold quantity established by the authority having jurisdiction and is sufficient to pose a threat to the public if released.a
Buildings and other structures required to maintain the functionality of other Risk Category IV structures.
|N||Lateral notional load used to evaluate conformance with minimum structural integrity criteria.|
|Fx||A minimum design lateral force applied to level x of the structure and used for purposes of evaluating structural integrity in accordance with Section 1.4.2.|
|Wx||The portion of the total dead load of the structure, D, located or assigned to level x.|
|Lr||Roof live load.|
Acceptable strength shall be demonstrated using one or more of the following procedures:
- the strength procedures of Section 184.108.40.206,
- the allowable stress procedures of Section 220.127.116.11, or
- subject to the approval of the authority having jurisdiction for individual projects, the performance-based procedures of Section 18.104.22.168.
- 1.2D + 1.0N + L + 0.2S
- 0.9D + 1.0N
- D + 0.7N
- D + 0.75(0.7N) + 0.75L+ 0.75(Lr or S or R)
- 0.6D + 0.7N
|Fx||=||the design lateral force applied at story x and|
|Wx||=||the portion of the total dead load of the structure, D, locatedor assigned to level x.|
Structures explicitly designed for stability, including second order effects, shall be deemed to comply with the requirements of this section.
When the building code or other referenced standard specifies an Occupancy Category, the Risk Category shall not be taken as lower than the Occupancy Category specified therein.
|Risk Category from
|Snow Importance Factor,
|Ice Importance Factor-Thickness,
|Ice Importance Factor-Wind,
|Seismic Importance Factor,
To qualify for this reduced classification, the owner or operator of the buildings or other structures containing the toxic, highly toxic, or explosive substances shall have an RMP that incorporates three elements as a minimum: a hazard assessment, a prevention program, and an emergency response plan.
As a minimum, the hazard assessment shall include the preparation and reporting of worst-case release scenarios for each structure under consideration, showing the potential effect on the public for each. As a minimum, the worst-case event shall include the complete failure (instantaneous release of entire contents) of a vessel, piping system, or other storage structure. A worst-case event includes (but is not limited to) a release during the design wind or design seismic event. In this assessment, the evaluation of the effectiveness of subsequent measures for accident mitigation shall be based on the assumption that the complete failure of the primary storage structure has occurred. The off site impact shall be defined in terms of population within the potentially affected area. To qualify for the reduced classification, the hazard assessment shall demonstrate that a release of the toxic, highly toxic, or explosive substances from a worst-case event does not pose a threat to the public outside the property boundary of the facility.
As a minimum , the prevention program shall consist of the comprehensive elements of process safety management , which is based upon accident prevention through the application of management controls in the key areas of design, construction, operation, and maintenance . Secondary containment of the toxic, highly toxic, or explosive substances (including, but not limited to, double wall tank, dike of sufficient size to contain a spill, or other means to contain a release of the toxic, highly toxic, or explosive substances within the property boundary of the facility and prevent release of harmful quantities of contaminants to the air, soil, ground water, or surface water) are permitted to be used to mitigate the risk of release. Where secondary containment is provided, it shall be designed for all environmental loads and is not eligible for this reduced classification. In hurricane-prone regions, mandatory practices and procedures that effectively diminish the effects of wind on critical structural elements or that alternatively protect against harmful releases during and after hurricanes are permitted to be used to mitigate the risk of release.
As a minimum, the emergency response plan shall address public notification, emergency medical treatment for accidental exposure to humans, and procedures for emergency response to releases that have consequences beyond the property boundary of the facility. The emergency response plan shall address the potential that resources for response could be compromised by the event that has caused the emergency.
Occupational Safety and Health Administration
200 Constitution Avenue, NW
Washington, DC 20210
OSHA Standards for General Industry, 29 CFR (Code of Federal Regulations) Part 1910.1200. Appendix A with Amendments as of February 1, 2000, United States Department of Labor, Occupational Safety and Health Administration, Washington, DC, 2005