“Incomprehensible jargon is the hallmark of a profession.”-Kingman Brewster
Jargon. A word that most of us have heard before. Many enjoy using certain phrases that amount to it, but others not so much. Every industry seems to have some jargon to explain ideas in a way to communicate with others efficiently. When you are new to a job though, it can be hard to get up to speed. The Process Safety world is no different, having what can seem to be endless words to learn. That should not be an excuse to lag, especially if it can lead to a safer workplace.
Words, Words, Words
In the process industry, engineers and operators alike create terms to pass information along quickly. Federal regulators and industry organizations like their own acronyms as well. Let us break down some essential terms that are used throughout Process Safety.
Industry Organizations
Some industries have helped develop proper practices and have been referenced in federal code regulations. More specifically, OSHA has used specific publications of codes from the American Petroleum Institute (API), International Society of Automation (ISA), International Electrotechnical Commission (IEC), and the National Fire Protection Agency (NFPA) for sources in some of its regulations.
The American Petroleum Institute (API) is the group that represents the oil and natural gas industry in the United States. They were formed in 1919 to set standards to improve “operational and environmental safety, efficiency and sustainability.” They continue to promote safety and are used as a resource for the OSHA Process Safety Management standard regarding highly hazardous chemicals.
The International Society of Automation (ISA) is a non-profit association founded in 1945 to develop standards as automation became more widely used in a variety of industries. They provide global standards, certifications for industry professionals, education, training. They also publish books and technical articles for their members and customers. OSHA has used ISA standards in their own regulations. For example, 1910.119(d)(3)(i)(F) requires the documentation of design codes and standards of Safety Instrumented Systems (SISs) used by an employer, which ties to S84.01 of ANSI/ISA code on the subject.
The International Electrotechnical Commission (IEC) is a membership organization that creates standards and terms of electrical apparatus and machines in response to Congress’s proposal after seeing the variety of methods that were displayed at the World’s Fair in 1904. They created the standards that regulate all electronics to this day. In fact, you have probably seen their IEC symbol on a power chord or adapter in the past. They are often referenced in OSHA electrical safety regulations.
The National Fire Protection Agency (NFPA) was created in 1896 to eliminate “death, injury, property and economic loss due to fire, electrical and related hazards.” The nonprofit organization created more than 300 standards to aide that mission. OSHA has used NFPA standards for their subsections and in their nonmandatory appendices.
Process Safety Management and Its Parts
Process Safety Management (PSM) is OSHA’s standard that is meant to prevent unwanted releases of hazardous chemicals, where employees and others could be exposed to those hazards. The standard can be found at CFR 29.1910.119 and consists of 14 elements that OSHA requires to be addressed for covered processes. Some terms that are commonly associated with the elements are: Piping and Instrumentation Diagram (P&ID), Process Flow Diagram (PFD), Process Hazard Analysis (PHA), Pre-startup Safety Review (PSSR), and Management of Change (MOC).
P&IDs and PFDS are thrown around together and are mentioned in multiple elements of PSM. Piping and Instrumentation Diagrams (P&IDs) are schematics of a process that includes detailed piping, equipment, and controls instruments. Process Flow Diagrams (PFDs) cover a process showing major pieces of equipment and unit processes. These diagrams are required for multiple points of PSM, such as Process Safety Information (PSI) and Process Hazard Analysis.
Process Hazard Analysis (PHA) is the process to consider probable hazards, safeguards, and recommendations to make a process safer. This process is required as the third element in the PSM standard. OSHA has listed acceptable methods to complete this process: What-If, Checklist, and Hazard and Operability Study (HazOp). While What-If and Checklist are self-explainable, HazOp is more complicated. HazOp is a systematic approach to identify possible hazards by using deviation-cause-safeguard-recommendation general formulae. This method is most popular among new and complex processes since it is thorough and systematic. This method relies more on itself rather than the people in the group who perform it.
A Pre-startup Safety Review (PSSR) is a process ran prior to the start-up of a facility to ensure that the installations meet the operating intent and to catch/reassess any potential hazards. This is one of the 14 elements described in OSHA’s PSM standard. A PSSR should be performed if significant changes were made to the process and is normally done in conjunction with Management of Change (MOC).
Management of Change (MOC) is the set of procedures a company must have to manage changes to the process, whether chemical, technological, equipment or procedure based. This is the 10th element in OSHA’s PSM standard.
Recognized and Generally Accepted Good Engineering Practice (RAGAGEP) is an acronym that OSHA coined to represent existing practices that are found in industries and codes that would fall under OSHA existing regulations, such as the PSM standard. It’s a general term for sure, but it serves as good starting point for Mechanical Integrity (MI) programs and facility siting.
LOPA and its Parts
Layer of Protection Analysis (LOPA) goes hand-in-hand with Process Hazard Analysis. LOPA is a process that assesses risk and evaluates hazards. It is regarded as a good follow-up for PHAs, as it can help quantify if the current safeguards are suitable enough to reduce risk to an acceptable level. It should be of no surprise that a LOPA is considered a Quantitative Risk Analysis (QRA). QRAs are processes that numerically analyze the effects of individual risks along with other uncertainty sources to meet the desired risk reduction. The results from the LOPA reports can be used to set Safety Requirement Specifications (SRS) for Safety Instrument Systems (SIS).
SIS and Components
Safety Instrumented Systems are systems designed for operating safety devices and ensuring the emergency stop is implemented whenever the process exceeds operational thresholds. These systems are a step up from Basic Process Control Systems (BPCS), as those are made to keep the process within the threshold for operation. Safety Instrumented Systems can be configurable to different tiers of reliability and carry different Safety Integrity Levels (SIL). An example would be High-Integrity Pressure Protection System (HIPPS), which are designed to prevent over-pressurization at a plant. Another could be a Burner Management System (BMS) which enables the safe start-up, operation, and shutdown of multiple burners for a boiler.
Safety Instrument Systems are made of Safety Instrumented Functions (SIF). SIFs are the pieces and controller that detect a specific hazard and brings the process to a safe state when operating thresholds are exceeded. Most SIFs are designed to reach a specific SIL rating to contribute to the Safety Requirements Specification (SRS). The SRS is a report that describes every required safety function that is performed by a SIS along with the how well they must perform.
SIFs are made of Independent Layers of Protection (IPL), which are devices, systems, or actions that can prevent a scenario from proceeding to an undesired consequence without being affect by the initiating event or another layer action. All SIFs are safeguards, but not all safeguards are SIFs. SIFs must meet the following attributes:
- Independent
- Functional
- Integrity
- Reliable
- Validated
- Maintained and Audited
- Access security
- Management of Change
To determine the SIL level, some calculations must be made of historical empirical data from the field. These calculations result in an Average Probability of Failure on Demand (PFDAVG). This probability will determine what SIL rating the SIF is able to achieve.
Risk and Consequence Analysis
OSHA has a lot to say on Process Safety Management, but the EPA has their own rule: Risk Management Program (RMP). Where OSHA is concerned with employee safety, the EPA’s focus is on the surroundings and the environment. Part of the RMP rule requires Offsite Consequence Analysis (OCA). OCA is a hazard assessment that evaluates the potential impacts that an accidental release would have on an area with modeling scenarios.
Process Hazard Analysis requires risk criteria as a basis which is a group of risk levels an employer can tolerate at different likelihoods. OSHA requires that risk tolerance criteria (RTC) be used, but doesn’t enforce a specific set, so these are often somewhat unique on a company basis.
Photo credit: Patrick Tomasso via Unsplash
There’s Always More
It is not surprising that there are more terms and acronyms that make up the jargon in Process Safety. Hopefully, the explanations above provide a jumping off point. If you would like further explanation on a topic, please don’t hesitate to reach out to us over at Bluefield. We would be happy to help inform and continue to make the world a safer place.
