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An Overview of OSHA's Process Safety Management Standard

Robert B. Coulter, P.E.

Course Outline

This two hour online course provides a basic understanding of OSHA's Process Safety Management Standard, 29 CFR 1910.119

This course includes a multiple choice quiz at the end.

Learning Objective

At the conclusion of this course, the student will:

         Have an understanding of the applicability of OSHA's Process Safety Management (PSM) standard

         Have a basic knowledge of the requirements of the PSM standard

About the Author

Robert B.Coulter, PE, is a provider of safety, process engineering and environmental consulting services including inhouse training on safety and environmental topics. For more information, visit his website at

Course Introduction

This course provides the user with an overview of the OSHA PSM (1910.119) standard which governs the management of processes involving highly hazardous chemicals. The course will show the conditions that will trigger compliance to the PSM standard and give a brief description of the specific elements (or requirements) of the standard.

Course Content


In 1992 OSHA issued the Process Safety Management standard to reduce the risk to employees from potential catastrophic incidents related to the processing of highly hazardous chemicals. This regulation was motivated, in part, by chemical disasters occurring in Bhopal, India and Pasadena, Texas in the 1980s. Although a relatively short standard, the scope is broad and in-depth. Many consider this to be the most difficult OSHA standard in terms of interpretation and compliance.


Compliance to the PSM standard will be required for each process meeting EITHER of the following criteria:

         Involves a chemical equal to or exceeding its threshold level listed in Appendix A of the PSM standard (1910.119)

         Involves a flammable liquid or flammable gas equal to or exceeding 10,000 pounds

The term "process" should be interpreted broadly because few exceptions are allowed. Generally, storage tanks operated strictly as such are exempt. Also, retail, fuel burning, oil/gas drilling, and remote unoccupied facilities may be exempted.

In calculating the amount of a listed chemical or flammable in a process, one may allow for mixtures by multiplying by the appropriate percentage. For example, if a process contains no more than 12,000 pounds of a grain alcohol (ethanol) and water mixture, where the ethanol percentage is 75%, then the maximum quantity of ethanol would only be (75% X 12,000) or 9000 pounds. This would not be a regulated process under PSM.

Separate processes, at the same facility, that each has less than a threshold quantity of a listed chemical or flammable may be exempted. This does not apply if the processes can be connected in some reasonable way. For example, a solitary pipeline connecting two processes (or a shared dike system) would require that the threshold quantity be calculated by summing the quantities in both processes. To extend the example, two reactors located in different buildings that each has more than 500 pounds of formaldehyde, whose threshold level is a thousand pounds, would be considered a single process if a single pipeline connected the two reactors. This would cause the threshold quantity to exceed the 1000 pounds limit and require the process to follow the PSM standard.

Requirements for Applicable Processes:

There are fourteen separate requirements, or elements, of the standard. Each element must be followed for all applicable processes. The letter following the name of each element is the reference to the corresponding paragraph in the standard. The elements and a description of each are:

1. Employee Participation (c)

Employees involved in applicable processes must be included in the development of compliance plans and procedures for each element of PSM. This, in almost all cases, will include a representative number of operators and maintenance personnel working on the applicable processes.

A written "Employee Participation Plan" must be made that outlines the role of employees in the PSM compliance program. One key aspect of this plan is the role of employees in the Process Hazards Analysis element (see below). It is recommended that this plan and other PSM procedures/documents be kept in a secure and controlled location. The plan must; however, be readily available to employees.

All information that an employer would use to develop compliance plans for PSM must be available to employees for inspection. This particularly applies to all Process Safety Information (See Process Safety Information element below).

2. Process Safety Information (d)

A compilation of all Process Safety Information (PSI) related to a process must be completed prior to conducting a Process Hazards Analysis (PHA) on that process. Process Safety Information is a description of all the known hazards of a process and the controls in-place to reduce the risks of the hazards.

A "compilation" generally means that the PSI is accessible in one location as opposed to being "scattered" throughout various files or documents.

"Known Hazards" are those hazards in a process known before the PHA. OSHA does not use the word "known" but this seems to be implied because OSHA specifies that the PSI be compiled BEFORE performing a PHA.

"Controls" is another word that should be interpreted broadly. These are basically ALL measures, administrative or technical, that is in-place to minimize the known hazards. An example of an administrative control is an Emergency Action Plan. An example of a technical control is a safety interlock that shuts off a feed pump when a tank is full. (Some prefer the term "engineering control" instead of technical control.)

OSHA groups PSI into three categories:

         Hazards of the chemicals and flammables in the process

         Information related to the technology of the process

         Information related to the equipment in the process

Examples of "hazards" include characteristics like toxicity, flammability, and permissible exposure limit (PEL). Many of these characteristics are normally listed in the Material Safety Data Sheet (MSDS) for the chemical or flammable. OSHA will normally accept the MSDS (placed in the PSI compilation) as complying with this part. A list of required chemical characteristics are listed in paragraph (d) of the standard (see 1910.119 link below).

The next two categories, technology and equipment, involve the "controls" of the process as mentioned above. The technology information refers to the overall design of the system and its operational limits. The equipment information relates to the specific equipment in the process. In both cases the information is meant to show the hazards identified in the process, the potential consequences on employees, and the design basis of the "controls" that are meant to reduce the risk of the hazards. OSHA mandates that certain "controls" be specifically listed in the PSI. This includes electrical classification, pressure relief design, and all pertinent design codes. (see paragraph (d) of the standard for a listing of all required "controls") OSHA considers these particular controls of such high importance that it is advised that an adequate explanation be provided in the PSI for any absence of these particular controls in a process. For example, one should provide a statement explaining that a process has no flammable chemicals for justifying the absence of explosion-proof motors.

3. Process Hazards Analysis (e)

Process Hazards Analysis (PHA) is a cooperative effort of individuals to determine the hazards in a process. The term PHA is often referred to the actual meeting of the individuals (or PHA team) as well as the documentation produced by the team. The team must determine the possible effects of these hazards on employees and the existing controls in-place to reduce the risk of the hazards. Where the team determines that a control is absent or inadequate for a hazard, a recommendation is issued to correct the deficiency.

It is important to note that the team must identify all hazards regardless of any existing controls that may be in-place to reduce the hazard. For example, it would be incorrect to not list an overpressurization hazard because of the presence of a pressure relief valve on a tank. The overpressurization should be listed as a hazard indicating the possible effects (injuries, etc.) on employees. The pressure relief valve would be listed as a technical (engineering) control. The team should consider the consequences of the failure of controls also. For example, the possibility of the failure of the relief valve must be considered.

OSHA will accept any of several generally known methodologies for doing PHAs. Two of the most popular are what if/Checklist and HAZOP. OSHA lists all the acceptable methodologies in paragraph (e) of the standard. A person with technical knowledge of the process and a person knowledgeable of the particular PHA methodology used must be present on the PHA team. OSHA does not specify a minimum time length of the PHA sessions. The team is free to decide the pertinent topics of discussion. OSHA; however, mandates that all PHAs must include a discussion of the facility (or process) sitting, human factors (human error or fatigue), and all previous incidents that were catastrophic or potentially catastrophic.

A system must be in-place for resolving the recommendations of the PHA team. All recommendations should be resolved as soon as possible. This system should document the expected completion time of the recommendation. All employees affected by the recommendation should be notified. Specifications concerning the process should be revised accordingly.

All PHAs must be reviewed at least every five years. The reviewing team must have the same qualifications as a standard PHA team mentioned above. The PSM standard became law in 1992. During the five year period between 1992 and 1997, all applicable processes in the US were required to have their first PHAs completed. Since it is now past 1997, all PHAs are either of the "review-type" or concern new processes. New processes should have their PHAs completed before startup. A good time for this is when the design is complete and the process equipment has not yet been purchased.

4. Operating Procedures (f)

An employer must have written operating procedures for each applicable process. The procedure must show the proper steps to operate the process safely. The procedure must include steps for startup, shutdown, temporary startup and shutdown (if applicable), and emergency shutdown. The procedure must also include all aspects of the PSI and PHA that are relevant to the operation of the process. The minimal specific requirements are listed in paragraph (f) of the standard. This includes items like the consequences of process deviations, hazards of the process, and controls in-place to reduce the hazards. It does not appear that OSHA wants redundant documentation of ALL the PSI embedded in the procedure. For example, the presence of a high temperature alarm and the response to the alarm should be included in the procedure because it has relevance to the operation. Conversely, the fact that a particular motor has a certain electrical classification rating does not appear to be something that needs to be mentioned in the operating procedure.

The operating procedures should be reviewed and/or revised as a result of changes to the process. The procedures must be certified at least once per year to be valid.

The employer must also have in-place safety procedures to cover control of hazardous energy and materials (Lockout/Tagout and Breakdown procedures) and entry into hazardous areas / confined spaces. Confined spaces and control of hazardous energy are also regulated by OSHA standards, 1910.146 and 1910.147, respectively.

5. Training (g)

It follows from the previous element that training would be required for operators. The operating procedures serve as the basis for this training. The training should include all aspects of operation with emphasis on the precautions needed to reduce the risk of a hazardous incident. Training on related safety procedures must also be done.

All operators should receive initial training before being allowed to operate an applicable process. The current operators of existing processes should receive refresher training at least every three years. The frequency of this training should be increased if the process is subject to change. Operators should be consulted concerning the frequency of training for a given process.

All training should be documented. At a minimum this should be the employee's identity, date of training, and the means used to verify the employee understood the training. The usual method is testing.

6. Contractors (h)

Employers have certain obligations to contractors working on or near applicable processes. The employer must inform the contractor of all the hazards associated with applicable processes. This should be consistent with the manner that regular employees are instructed per elements (f) and (g) above. The contractors must also be informed of the facility emergency action plan and the proper action to be done in the event of an emergency.

The contractor's company has obligations also. The contracting company must ensure that all its employees working in a client's PSM processes are familiar with the hazards and have the necessary training to perform their job safely. This includes the emergency action plan and related safety procedures for the client's facility. The contracting company must document all training for its employees in a similar manner as mentioned in the training element above.

The employer must evaluate the performance of new and existing contractors to ensure that they have the proper skills to perform work associated with the applicable processes. A separate injury/illness log should be made for contractors working in applicable process areas. The employer should use this criterion for selecting and/or retaining contractors. For example, a contracting company that fails to adequately train its employees on confined space entry may no longer be used.

The term "contractor" is meant by OSHA to refer to "process" type contractors. Contractors who would not be associated with PSM process areas would not be regulated by this element. Also, it appears that OSHA is interpreting "contractor" to apply to contractors whose work tends to be more of a maintenance nature. If a contractor actually performed operations on a process it is assumed that OSHA would want all the elements to apply.

7. Pre-Startup Safety Review (i)

A pre-startup safety review (PSSR) is a verification that a facility has been installed according to its design, and that all pertinent operating, maintenance, and safety procedures are valid and in-place. Whenever a change occurs to a facility where the Process Safety Information (PSI) changes, then a pre-startup safety review is required. Changes that are not significant enough to cause and change in the PSI need only follow the element (l), Management of Change.

The word "facility" is used here instead of "process". The facility is all those things (pipes, vessels, building) that contain a process. To avoid confusion, it is recommended that some form of a PSSR be involved in all process changes that are not "replacement-in-kind". See the Management of Change element below for more details.

OSHA stipulates in this section that a BOTH a PHA and a PSSR is required for any new facility containing an applicable process.

8. Mechanical Integrity (j)

There must be a program in-place to ensure the integrity of key equipment involved in PSM processes. This program must be preventive in nature and not be triggered by breakdown in the equipment. The equipment that is subject to a mechanical integrity program (MIP) is:

         Pressure Vessels and Storage Tanks

         Piping Systems

         Relief and Vent Systems

         Emergency Shutdown Systems

         Controls (monitoring devices, sensor, alarms, and interlocks)


The MIP should document specifically which equipment is subject to preventive maintenance and the methods used to perform the preventive maintenance. The MIP must use inspection and maintenance procedures consistent with applicable codes, accepted practice, and manufacturer's recommendations. Maintenance personnel working on the MIP must be properly trained to do their jobs and informed of the hazards.

Records of all equipment specifications must be made. This should include the date of inspection, the inspector's identity, type of inspection or test, result of the inspection or test, and action taken. A system must be in-place to resolve all deficiencies. Equipment deemed too unsafe to operate must be removed from service.

A quality assurance program should be in-place to ensure that new equipment and spare parts are purchased and installed per the facility's and manufacturer's specifications.

9. Hot Work Permit (k)

Hot Work is a work activity that can generate a spark, heat, or flame. This type of activity must be carefully controlled to avoid causing a fire or explosion. OSHA standard 1910.252(a) covers the required precautions prior to conducting hot work. This element further specifies that a "Hot Work Permit" be issued documenting the date and location of hot work. It is recommended that hot work permits be issued by one person, preferably someone in supervision who is aware of all activity occurring in the area.

10. Management of Change (l)

Management of Change (MOC) is an activity to regulate modifications to a process. In most cases it also refers to the actual document that is used to initiate a change. MOCs are meant to address minor changes to processes. It is a good idea; however, to use the MOC as the gateway to all modifications. MOCs are initiated whenever a change is desired in an applicable process. The MOC is usually initiated by completing a form describing the change, its purpose, and its potential impact on hazards. The MOC is then reviewed by specified individuals. If the MOC is approved, then the change is allowed to be implemented. MOCs are not required for normal maintenance work as long as replacement parts meet existing facility or manufacturer's specifications (also called "replacement-in-kind").

A written MOC procedure must be in-place describing the manner that an MOC is initiated, approved, and implemented. An MOC can affect nearly all elements of PSM. Documentation generated to comply with these elements may need to be revised as the result of implementing an MOC. For example, a change in the type of pump used to feed a hazardous chemical can affect the operating procedure, training, mechanical integrity, emergency response, process safety information, and/or pre-startup safety review. All employees and/or contractors affected by the MOC need to be informed and/or trained prior to the change going into effect. It is a good idea to document the training resulting from an MOC.

11. Incident Investigation (m)

All catastrophic or potentially catastrophic incidents involving applicable chemicals or flammables must be investigated. This investigation must start within 48 hours of the incident. An investigation team should be assembled which includes those knowledgeable of the process and those involved in the incident (if available). A report should be written documenting the timeline of the incident and investigation, the likely cause of the incident, and recommendations for corrective action. A system should be in-place to implement the corrective actions. This system should resolve the incident recommendations similar to the resolution of PHA recommendations above.

It is a good idea to have an incident investigation procedure to show how incident investigations involving applicable processes are performed. This can be incorporated into a "master" investigation plan that covers other types of incidents or accidents that may occur at a facility.

12. Emergency Planning and Response (n)

A written plan must be in-place to respond to emergencies involving applicable processes. Almost all sites that have PSM processes would have been required to have a written emergency action plan because of previous regulations. OSHA specifies here that the emergency action plan must comply with the standards in 1910.38(a) and 1910.120(a)(p)(q).

The essential elements of an emergency action plan will cover evacuation and the degree of involvement of facility employees. OSHA specifies strict training requirements based on the degree of involvement of on-site personnel. A site may wish to decide not to get involved in an incident and let local emergency response personnel handle it. In this case, the emergency action plan will focus on evacuation and notification.

13. Compliance Audits (o)

An employer must conduct a documented audit of its PSM compliance program. This should be done by at least one individual with knowledge of the process. An action plan to resolve the findings of the audit should be implemented. This is similar to resolving PHA and incident investigation findings. An audit must be done at least every three years for each process. The documentation from the last two audits should remain on-site.

14. Trade Secrets (p)

An employer must disclose all pertinent information concerning applicable chemicals and/or processes protected by trade secret status to those parties developing compliance plans/procedures for PSM. The employer reserves the right to bind those parties receiving the information to a secrecy agreement.

Course Summary and Conclusions

OSHA's Process Safety Management Standard is a broad and intensive standard designed to minimize the risk of catastrophic disasters associated with the processing of hazardous chemicals. The elements of the standard rely on a cooperative effort of all individuals whose work is associated with applicable processes. A successful program is a well documented program in which everyone understands his or her role.

To conclude this course the student should read the actual text of the standard by following the first link below. The student should also read OSHA's interpretation of the standard by reading the second link. After reading the required course material the student should be ready for the test. The last link is the list of highly hazardous chemicals subject to PSM.

Related Links

For additional technical information related to this subject, please visit the following web sites or web pages:

OSHA's Process Safety Management Standard (1910.119)
OSHA's Recommendation and Guidelines for PSM
OSHA's List of Highly Hazardous Chemicals

Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

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DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered professional engineer. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.