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Reducing Agent
In a reduction reaction (which always occurs simultaneously with an oxidation reaction) the reducing agent is the chemical or substance which 1) combines with oxygen and 2) loses electrons in the reaction. See also, "Oxidizing Agent". Importance: If a material is listed as a reducing agent on the MSDS, precautions must be taken in the handling and storage of the substance. Keep separate from oxidizing agents.
Redundancy
The existence of more than one means of performing a required function or for representing information.
Redundant
A parallel path in a system structure to improve the system safety or reliability.
Reflux
A system condition in which a component in the reaction system (usually a solvent or diluent) is continuously boiled off, condensed in a nearby condenser and subsequently re-supplied to the reaction system. Reflux is often applied to operate at a preset temperature or to avoid operating at unacceptably high temperatures.
Refrigerated Liquid
A gas that is maintained as liquid at temperatures at or below ambient temperature to reduce the storage pressure. This includes fully refrigerated LP-Gas for pressures near atmospheric pressure but not exceeding 15 psi (103 kPa) and semi refrigerated LP-Gas for pressures above 15 psi (103 kPa). (NFPA 58)
Related criteria
Audit criteria derived from good, successful, common, or best practices in PSM that are not considered compliance issues, but supplement and improve a PSM program that meets the minimum compliance requirements. The evaluation of PSM management systems and the internal controls they impose are performed using related criteria.
Reliability
Core attribute of a protection layer related to the probability that the equipment operates according to its specification for a stated period of time under all relevant conditions.
Reliability Analysis
The determination of reliability of a process, system, or equipment.
Reliability Parameters
The collection of mathematically defined properties (e.g., Reliability, Availability, Dependability) used in reliability engineering to describe the behavior of systems and their elements, such as chemical processes, process systems, equipment and their components. (See Appendix E.)
Reliability-Centered Maintenance (RCM)
A systematic analysis approach for evaluating equipment failure impacts on system performance and determining specific strategies for managing the identified equipment failures. The failure management strategies may include preventive maintenance, predictive maintenance, inspections, testing, and/or one-time changes (e.g., design improvements, operational changes).
Remaining Life
An estimate, based on inspection results, of the time it will take for an equipment item to reach a defined retirement criterion (e.g., minimum wall thickness).
Repair Time
The time necessary to identify and repair a fault. The average detection and repair time is called the MTTR. Dimension (Time).
Repeat-back
A method of communication that requires the receiver to repeat the message back to the sender to validate that the appropriate message was received.
Replacement-in-kind (RIK)
An item (equipment, chemical, procedure, etc.) that meets the design specification of the item it is replacing. This can be an identical replacement or any other alternative specifically provided for in the design specification, as long as the alternative does not in any way adversely affect the use of the item or associated items.
Representative Set (of incidents)
A selection of incidents designed so as to contain one or more incidents from each of the three incident classes (localized, major, and catastrophic).
Representative Unit
A unit part of a unit that is covered by the PSM program that is being audited. When the potential scope of the audit would include a large number of units or equipment, focus units are sometimes used to help the auditors select records and documents for review, and people to interview, so that these inputs are sampled from a small number of selected units which are then considered typical of all covered units.
Resolution
Management's determination of what needs to be done in response to an audit finding (and/or associated recommendation), incident investigation team recommendation, risk analysis team recommendation, and so forth. During the resolution step, management accepts, rejects for cause, or modifies each recommendation. If the recommendation is accepted, an action plan for its implementation will typically be identified as part of the resolution. (See Implementation.)
Resources
The labor effort, capital and operating costs, and other inputs that must be provided to execute work activities and produce work products.
Respiratory System
The breathing system; in includes the lungs and air passages (trachea or "windpipe", larynx, mouth, and nose) to the air outside the body, plus the associated nervous and circulatory supply. Importance: Inhalation is the most common route of exposure in the occupational workplace.
Responsibility
The single person who has been assigned and has accepted the ultimate accountability for the development and or implementation a program, its separate activities, as well as its success or failure. There can be only one person with the ultimate responsibility for something. Although accountability enters into this definition, that term is used separately in this book.
Restart, Cold Start
Restart of the PES and its Application Program after all dynamic data (Variables such as I/O Image, internal Registers, Timers, Counters, etc., and Program Contexts) are reset to a predetermined state. A Cold Restart may be automatic (e.g., after a Power Failure, a loss of information in the dynamic portions of the memories of manual (e.g., push-button reset, etc.)).
Restart, Hot Restart
Restart after power failure which occurs within the process dependent maximum time allowed for the PES to recover as if there had been no power failure. All I/O-information and other dynamic data as well as the Application Program context are restored or unchanged. Restart capability requires a separately powered real time clock or timer to determine elapsed time since the power failure was detected and a user accessible means to program the process dependent maximum time allowed.
Restart, Warm Restart
Restart after Power Failure with a user programmed predetermined set of dynamic data and a system predetermined Application Program context. A Warm Restart is identified by a status flag or equivalent means made available to the Application Program indicating that the Power Failure shutdown of the PES was deleted in the RUM mode.
Retrofit, Update, and Revalidate
To correct substantive deficiencies in the prior PHA, and then update and revalidate it (See Update and Revalidate).
Revealed Failure
A failure that may be immediately or almost immediately apparent through an alarm or indicator system. This can lead to corrective action within a relatively short period of time.
Revealed Faults
A failure may be immediately or almost immediately apparent through an alarm or indicator system. This can lead to corrective action within a relatively short period of time.
Risk
A measure of human injury, environmental damage, or economic loss in terms of both the incident likelihood and the magnitude of the injury or loss.
A simplified version of this relationship expresses risk as the product of the Frequency and the Consequence of an incident (i.e., Risk = Frequency x Consequence). For example, Frequency may be expressed as "events/year" and Consequence as "impact/event" (F = 1 release/year; C = 1 fatality/release; with R = 1 fatality/year for the release scenario).
Risk Acceptance Criteria
See Risk tolerance criteria.
Risk Analysis
The estimation of scenario, process, facility and/or organizational risk by identifying potential incident scenarios, then evaluating and combining the expected frequency and impact of each scenario having a consequence of concern, then summing the scenario risks if necessary to obtain the total risk estimate for the level at which the risk analysis is being performed.
Risk Assessment
The process by which the results of a risk analysis (i.e., risk estimates) are used to make decisions, either through relative ranking of risk reduction strategies or through comparison with risk targets.
Risk Based Approach
A quantitative risk assessment methodology used for building siting evaluation that takes into consideration numerical values for both the consequences and frequencies of explosion, fire, or toxic material release.
Risk Based Inspection
A risk assessment and management process that is focused on loss of containment of pressurized equipment in processing facilities, due to material deterioration. These risks are managed primarily through equipment inspection.
Risk Based Process Safety (RBPS)
The Center for Chemical Process Safety's process safety management system approach that uses risk-based strategies and implementation tactics that are commensurate with the risk-based need for process safety activities, availability of resources, and existing process safety culture to design, correct, and improve process safety management activities.
Risk Contour
Lines that connect points of equal risk around the facility ("isorisk" lines).
Risk Control Measure
Characteristic associated with a process that is expected to reduce the likelihood and/or severity of a loss event.
Risk Escalation
A risk management system whereby an increasingly higher level of authorization is required to sanction the continued tolerance of increasingly higher levels of risk. Some organizations use the term risk elevation.
Risk Estimation
Combining the estimated consequences and likelihood of all incident outcomes from all selected incidents to provide a measure of risk.
Risk Evaluation
Comparison of results of a qualitative or quantitative risk analysis coupled with an appraisal of the significance of the results, both overall and from individual events.
Risk Evaluation Criteria
A qualitative or quantitative expression of the level of risk that an individual or organization is willing to assume in return for the benefits obtained from the associated activity.
Risk Factor
Along with the probability that an event will occur (risk) are those factors of behavior, lifestyle, environment, or heredity associated with increasing or decreasing that probability.
Risk Management
The systematic application of management policies, procedures, and practices to the tasks of analyzing, assessing, and controlling risk in order to protect employees, the general public, the environment, and company assets, while avoiding business interruptions. Includes decisions to use suitable engineering and administrative controls for reducing risk.
Risk Matrix
A tabular approach for presenting risk tolerance criteria, typically involving graduated scales of incident likelihood on the Y-axis and incident consequences on the X-Axis. Each cell in the table (at intersecting values of incident likelihood and incident consequences) represents a particular level of risk.
Risk Targets
Objective-based risk criteria established as goals or guidelines for performance.
Risk Tolerance
The maximum level of risk of a particular technical process or activity that an individual or organization accepts to acquire the benefits of the process or activity.
Risk Tolerance Criteria
A predetermined measure of risk used to aid decisions about whether further efforts to reduce the risk are warranted.
Risk-Based Inspection (RBI)
A systematic approach for identifying credible failure mechanisms and using equipment failure consequences and likelihood to determine inspection strategies for equipment.
Roll Over
The spontaneous and sudden movement of a large mass of liquid from the bottom to the top surface of a refrigerated storage reservoir due to the instability caused by an adverse density gradient. Rollover can cause a sudden pressure increase and can affect vessel integrity.(API 2510)
Root Cause Analysis (RCA)
A formal investigation method that attempts to identify and address the management system failures that led to an incident. These root causes often are the causes, or potential causes, of other seemingly unrelated incidents. Identifies the underlying reasons the event was allowed to occur so that workable corrective actions can be implemented to help prevent recurrence of the event (or occurrence of similar events).
Root Causes
A fundamental, underlying, system-related reason why an incident occurred that identifies a correctable failure(s) in management systems. There is typically more than one root cause for every process safety incident.
Round Robin
A process involving an exchange of samples intended to transfer analytical capabilities from the client to the toller to support the toll project.