Developing and Implementing Effective Ammonia Refrigeration System Operating Procedures

Michael Keller, CIRO PSM Compliance Specialist, Bassett Mechanical


This paper provides guidance on developing and implementing operating procedures for ammonia refrigeration systems. The regulatory information is based on the U.S. Occupational Safety and Health Administration (OSHA) Process Safety Management (29CFR1910.119) standard (1992), the Environmental Protection Agency (EPA) Chemical Accident Prevention Provisions’ (40 CFR part 68) Risk Management PlanRule(1996), and the IIAR standards for Developing Operating Procedures for Closed-Circuit Ammonia Refrigeration Systems (ANSI/IIAR7-2013). Other focus areas include a step-by-step guide and recommendations for effective technical writing, training, and various related topics.


Written operating procedures are necessary to ensure the ammonia refrigeration system operates within its design parameters and to minimize the possibility of an unplanned, unintended ammonia release. OSHA recognizes this necessity by making operating procedures a requirement of the process safety management (PSM) program.

The first part of 29 CFR 1910.119(f) (1) (OSHA 1992) states [author’s emphasis] “The employer shall develop and implement written operating procedures that provideclear instructions for safely conducting activities involved in each covered process.”

The purpose is “safely conducting activities” on the covered process, that is, the ammonia refrigeration system. The goal has been and always will be safety. While compliance with OSHA and EPA requirements is important, the true objective is the safety of employees and the welfare of the public. All other positive outcomes are the result of achieving the primary goal of safety. Costly OSHA and EPA citations are prevented. Equipment is undamaged. Significant periods of downtime are averted.

The environment is protected from toxic contamination. Significant financial loss due to contaminated food products is avoided. Customers are happy. Consumers are happy. Trust in the company is preserved, and the public image of the company’s good name is protected.

There are several other good reasons for developing and implementing written procedures for operating the ammonia refrigeration system. Operating procedures help ensure consistency among operators and shifts. Everyone operates the equipment in the same way using the same parameters. Unsafe conditions created by operators taking shortcuts are prevented, and the operator who attempts a better, faster, and easier way can be held accountable.

Written operating procedures help to preserve continuity through the revolving door of operators and technicians. As operators come and go, the way the equipment is operated often gradually shifts. Subtle changes in procedures pass from operator to operator. The procedures and operating conditions of today look nothing like they did when the equipment was first commissioned. The changes become normalized over time and often result in the equipment being operated outside its intended design operating conditions.

Written operating procedures save time and money. Operators do not have torely on the supervisor or other operators when they are unsure about a particular procedure. Step-by-step procedures provide operators a defined path for completing their task and gives them confidence knowing they are performing the procedure correctly and safely.

Written operating procedures are also useful for training new operators. The IIAR’s “Process Safety Management & Risk Management Program Guidelines” (2012) states that written procedures should be the “primary training tool” for operator training. When training new operators, the procedures should be used to help ensure important details are not missed and to verify that the operator understood the training.


An effective operating procedure should provide enough information to allow a trained operator to control the operation of the refrigeration system and its equipment successfully and safely. It should detail the action steps required to start and stop the system and its equipment. The procedure should provide normal operating parameters and designed maximum allowable limits to minimize the possibility of a catastrophic incident caused by operator error.

Written operating procedures aim to provide well-defined and detailed instructions for operating the refrigeration system. They should be written such that operators can easily understand them at their reading level. The operators are the target audience, and the writer needs to consider their backgrounds and levels of education. English may not be the operator’s primary language. Procedures should be written to meet everyone’s needs, even if that means translating the procedures into another language.

Written procedures should use terms and titles used at the facility and known by the operators. If the high-temperature vessel is called an accumulator, it should not be referred to as a receiver. If the main electrical room is called the MCC Room, it should not be referred to as the Main Electrical Panel Control Room. To avoid confusion, refer to equipment by its known designations.

Written operating procedures should be equipment specific. They should be more than general operating guidelines for various equipment types. Procedures should provide action steps that are specific to the equipment being operated yet written to be both comprehensive and concise. To be effective, written procedures should be detailed enough to ensure all the necessary information for completing the tasks is included but written briefly and succinctly.

Finally, written operating procedures should be accurate, reliable, and in agreement with the manufacturer’s recommendations. When changes are made to equipment, processes, and operations, the procedures should be updated accordingly and reflect current operating conditions at the facility.


This section covers both the OSHA PSM standard (1992) and the EPA risk management plan (RMP) rules (1996). In November of 1990, amendments to the Clean Air Act (originally 1963 and 1970) were enacted into law by Congress. These amendments required OSHA and EPA to develop standards for chemical process safety to protect workers, the public, and the environment from accidental releases of highly hazardous chemicals. In reality, OSHA had already published the initial draft of Process Safety Management of Highly Hazardous Chemicals in the federal register and started the public review process six months prior. The final version of the standard was adopted in February of 1992. The EPA published its final version of the rule, the Accidental Release Prevention Requirements: Risk Management Programs (RMP) in June of 1996. The language of the prevention program section is nearly identical to OSHA’s PSM program.


Some OSHA standards provide very specific instructions on what is required. For example, standard railings for floor and wall openings must be constructed so that the vertical railing is 42 in. high and includes an intermediate rail halfway up. The PSM standard, however, is a “performance-based” standard. When OSHA creates a performance-based standard, it states “what” must be performed, but does not dictate “how” to perform it. For instance, in the training element of the PSM standard, OSHA requires that the means used to verify that an employee understood the training are documented. But it does not dictate the method of verification, whether it is a written test, through demonstration, a verbal exchange, and so forth.

As a performance-based standard, PSM requirements are written to achieve a specific objective. Emphasis is placed on the desired outcome. The desired outcome in this case is to ensure the refrigeration system is operated safely and prevent catastrophic incidents. Making the standard performance based means that companies have the flexibility to tailor their programs to the facility’s and employees’ needs. The challenge for companies is deciding at what point their program complies with the regulation and whether OSHA will agree.

In June of 2017, OSHA gave an update on its National Emphasis Programs (NEP) from 2014 to 2016, noting that 66% of all general industry violations from NEP inspections during that period were related to the PSM program. Of the 14 PSM program elements, violations related to operating procedures were the fourth leading cause of citations at 13.5% (OSHA 2017). It is important that written operating procedures are in place, that they contain accurate and complete information, and that operators are trained to perform the procedures as written.


The operating procedures requirement of the PSM program is the fourth of 14 elements included within the program—-after the employee participation, process safety information, and process hazard analysis sections, which may or may not be by design. Regardless, the three previous sections should play an intricate role in the proper development of the written operating procedures.

The employee participation element requires that employees are consulted on the “conduct and development of process hazards analyses and on the development of the other elements of process safety management in this standard” (OSHA 1992; 1910.119(c)(2)). This includes the operating procedures element of the standard.

Consulting the workers makes sense. The operators interact with the equipment every day and can be the best resource for understanding how it operates. Even during new system startups, employees can provide feedback on the standard operating procedure (SOP) format and how to make them easier to understand and follow.

The process safety information (PSI) element is the single most important element when developing operating procedures. This information is the foundation for developing operating procedures, and they cannot be completed without it. For instance, an accurate set of piping and instrumentation diagrams (P&IDs) is necessary for identifying valve positions during normal operations and shutdowns.

Health hazards identified in the PSI section should be referenced and included within the operating procedures. Safety systems and their function, safe lower and upper operating limits, the consequences of deviation, and the steps needed to correct or avoid them are all associated with both elements of the PSM program. Therefore, ensuring all necessary information has been compiled and is ready for quick reference is required.

The process hazard analysis (PHA) also has an important role in developingwritten operating procedures. The PHA is used to identify hazards and potential failures within the ammonia refrigeration process. Some hazards are mitigated by engineering controls designed into the system. The high-level float switch on a low- pressure receiver is a good example. Other hazards are controlled administratively through the use of specific operating procedures. For instance, hazards associated with opening the system are addressed through the use of a line break procedure.

The PHA generates a list of operating procedures that should be written to address specific hazards. The operating procedures section 1910.119(f) (OSHA 1992) is divided into four subparagraphs:

  1. Development and Implementation (f)(1);
  2. Accessibility (f)(2);
  3. Review, changes, and certification (f)(3); and
  4. Safe work practices (f)(4).


OSHA (1992) begins the operating procedures paragraph section by stating the following:

“The employer shall develop and implement written operating procedures that provide clear instructions for safely conducting activities involved in each covered process consistent with the process safety information and shall address at least the following elements.” 29 CFR 1910.119(f)(1)

The employer is responsible for developing and implementing written operating procedures. Providing verbal instructions is insufficient. The procedures must be written and implemented as part of the process operation. Two things should be addressed when developing written operating procedures: clarity and consistency.

First, written operating procedures should provide “clear instructions” to ensure the ammonia refrigeration system is operated safely. As discussed previously, the procedures should be easily understood by the operators. They should provide specific instructions for operating the system and its individual components.

Second, the written procedures must be consistent with or in agreement with the PSI. This is one reason why the PSI needs to be complete and accurate. This cannot be overstated. Developing written procedures and then realizing the P&IDs are inaccurate is a costly mistake.

The standard requires the following elements to be addressed within the operating procedures:

  1. Steps for each operating phase,
  2. Operating limits,
  3. Safety and health considerations, and
  4. Safety systems and their functions.


The standard provides a list of operating phases, which is generally considered the minimum number of procedures required. These operating phases include

  • Initial startup;
  • Normal operations;
  • Temporary operations;
  • Emergency shutdown, including the conditions under which emergency shutdown is required and the assignment of shutdown responsibility to qualified operators to ensure that emergency shutdown is executed in a safe and timely manner;
  • Emergency operations;
  • Normal shutdown; and,
  • Startup following a turnaround, or after an emergency shutdown.

OSHA does not define the individual operating phases because the standard is performance based, allowing companies to have the flexibility to define operating phases to meet their needs. The EPA booklet “General Guidance on Risk Management Programs for Chemical Accident Prevention (40 CFR PART 68)” (2009) provides some guidance and insight into the various phase elements. But this is a guidance document only and should not be considered legally binding. The following are brief descriptions of each operating phase:

Initial startup refers to the steps required to verify the equipment is ready for startup and the actions to start the equipment are performed. This step may include visual inspections, pressure tests and evacuation, electrical system checks, and programming setpoints. Once the equipment is prepared, the procedure should include the necessary steps to start the equipment, such as leak checks, valve positioning, startup, verification, and so on.

Normal operations refers to actions taken while operating the equipment under normal conditions. This step may include procedures to ensure the equipment is operating within its normal design parameters, such as making visual inspections and completing the operating logs.

Temporary operations refers to actions taken to operate the refrigeration system when it is operating outside normal operation. For example, during off production hours cross-over valves are opened to equalize pressure among systems. In this case, the procedure should include steps taken to ensure changes to the system are performed safely and adequately.

Emergency shutdown refers to actions taken to shut down the system and equipment when an emergency upset occurs. This procedure must define when an emergency shutdown is required and who is both qualified and responsible for performing the emergency shutdown.

Emergency operations refers to actions taken to continue operating the system during an emergency. If the plant is not operated during an emergency, this procedure would not apply.

Normal shutdown refers to actions taken to stop equipment under normal circumstances, which could be as simple as pushing a button and verifying system conditions.

Startup following a turnaround, or after an emergency shutdown refers to actions taken to restart the system after a significant shutdown has occurred, such as after an emergency or an extended period of maintenance. Referring to the initial startup procedure is not uncommon, as many of the steps follow the same sequence.

The EPA guidance document (2009) stresses an important point. Companies should not “spend any time on” procedures for operating phases not applicable to their system or equipment.


Operating procedures must include the operating limits of the equipment. This could include normal operating limits and maximum allowable limits. Normal operating limits usually refer to the operating limits based on the operational needs of the facility and product. Maximum allowable limits, however, refer to the safe operation of the equipment, and operating outside of these limits will cause an unsafe condition.

The “consequences of deviation” and “steps required to correct or avoid deviation” must be included. The operator must be provided information on what specific dangers are posed when operating the system outside its acceptable operating limits. The steps needed to avoid the deviation and to bring the system back within acceptable limits must be included.


Under the procedure’s safety and health section, operators must be provided information regarding ammonia’s properties and health hazards. Some of this information can be easily obtained from the safety data sheet and process safety information. However, it must be provided within the operating procedures for quick and easy reference for the operator. The operator must be informed of precautions to prevent exposure and control measures if exposure does occur. Ammonia quality and inventory control measures should be specified, as well as any other hazards that may be unique to ammonia.


The operating procedures must include a list of all safety systems and their functions. This list could include ammonia detection systems, alarm and cutout functions, pressure relief systems, emergency shutdown systems, liquid control systems, ventilation controls, and so on. Information related to function may include the type of safety control, how it is activated, and its activation point if activated automatically.


The operating procedures must be made “readily accessible” to the employees. How this is accomplished is up to the employer. The procedures can be printed or made available electronically on a computer. Whichever way the procedures are made available, they should be available and easily obtained. Having a contingency plan is a good idea if the computer crashes or the paper copies are lost.


Once the procedures are created, they must be maintained and kept current. There are two separate requirements. OSHA requires that the procedures are

  • Reviewed as often as necessary to ensure that they reflect current operating practices, and
  • Certified annually as being current and accurate.

The standard requires the procedures to be reviewed “as often as necessary” to ensure accuracy. This does not mean written procedures need to be reviewed annually. As often as necessary may only require the procedures to be updated during a management of change procedure. In a letter of interpretation dated March 9, 1994, OSHA states, “There is no requirement for an annual review” if an effective management of change system is in place ensuring that the procedures are updated when modifications to the system occur. However, this is a very big “if” for many companies, so a periodic review may be prudent and worth the effort.

Employers must certify annually that the procedures are current and accurate. The certifier should be someone who represents the employer, such as an engineering manager, a utilities supervisor, or similar. A formal certification document or some other method should be developed to show the procedures have been certified as being accurate.


Finally, the OSHA PSM standard for operating procedures requires employers to “develop and implement safe work practices” to control hazards associated with operating and maintaining the ammonia refrigeration system. The list of safe work practices include

  • Lockout/tagout,
  • Confined space entry,
  • Opening process equipment , and
  • Control over entrance into the facility.

The safe work practices “shall apply to employees and contractor employees” who operate and maintain the system. The employer is responsible for ensuring that the procedures are being adhered to.


Advocating for “the safe, reliable and efficient use of ammonia and other natural refrigerants,” IIAR is tasked with developing consensus standards for the ammonia refrigeration industry. Consensus standards adopted by the industry may not reduce or detract from the minimum requirements set by OSHA and EPA. However, they may add additional requirements specific to the industry they represent. These additional requirements become industry standards adopted by regulatory agencies, and industries are held accountable for following them.

As of March 2019, IIAR is in the final stages of updating ANSI/IIAR 7-2013, “Developing Operating Procedures for Closed-Circuit Ammonia Refrigeration Systems.” This standard follows many of the requirements of the OSHA PSM standard (1992). However, it includes some additional elements. This paper will focus on and attempt to highlight the additional requirements in the IIAR standard.

The IIAR standard is divided into four sections:

Part 1—General is the introductory section that presents the purpose and scope, definitions for terms, and reference standards.

Part 2—Developing and Maintaining Operating Procedures outlines general requirements that must be followed for developing and maintaining operating procedures.

Part 3—Equipment lists by equipment type items to consider when documenting operating procedures.

Part 4—Appendices is informative only and consists of explanatory material, operating procedure documentation, operating procedures for specialized equipment, and reference sources. It should not be considered part of the standard for compliance.


The IIAR standard aims to provide minimum requirements for developing written operating procedures. It applies to facilities that utilize ammonia as the refrigerant in a “stationary closedcircuit refrigeration system.” Its scope is “for those who develop, define, or review operating procedures,” and all facilities with closed-circuit ammonia refrigeration systems “shall comply with” the requirements of the standard. Note that the standard applies to all systems matching these criteria, not just systems with 10,000 or more pounds of ammonia. Regardless of size and activity, the industry requirement is based on the type of system (stationary closed-circuit refrigeration) and refrigerant being used (ammonia).

Part 2, Chapter 4.1 reaffirms this requirement: “Written operating procedures shall be developed and implemented to provide clear instructions for safely conducting activities involving the closed-circuit ammonia refrigeration system.”


Part 2 of the IIAR 7-2013 provides requirements for general content that the operating procedure must include. The written procedures must address a minimum number of operating phases, referred to as “activities.” These activities include initial startup, normal operations, temporary operation, normal shutdown, emergency shutdown, and emergency operations. One procedure is changed from “startup procedures following a turnaround” to “startup procedures following abnormal shutdown conditions or turnarounds” and specifies power failures and emergency shutdowns as examples.

Along with the operating phases already mentioned, the IIAR requires the procedures to be “customized to reflect the type and the style” of the equipment. Procedures for nonroutine tasks are also required and should be developed while planning the project or task. The miscellaneous topics section of this paper provides further discussion on procedures for nonroutine tasks.

The IIAR has identified the following six safety and regulatory concerns that must be considered and addressed within the SOP:

  1. Personal protective equipment;
  2.  Buddy system (an additional item that is not in the PSM standard);
  3. Lockout/tagout procedures;
  4. Confined space entry procedures;
  5. Equipment and piping opening procedures; and
  6. Regulatory requirements, which indicate that the procedures must comply with regulatory requirements.

Chapter 5 of IIAR 7-2013 outlines requirements for maintaining the operating procedures. This chapter follows many of the same OSHA PSM requirements for accuracy and availability. The procedures must be reviewed and updated as needed when changes are made to the system. Operators and technicians must be able to “obtain current operating procedures quickly and easily” to do their job. The caveat is to ensure the operator has the most up-to-date and accurate procedure. The IIAR standard specifies, “The version of each operating procedure shall be documented so that changes made to the operating procedures can be clearly tracked” (IIAR 2013, 5.1).

A system must be in place to document the version of the procedure. This can be a revision date, a revision number, or any other method deemed appropriate. It is used to track changes made to the procedures and to help the operator ensure he or she has the most current procedure in hand when performing a task.

Part 3 of IIAR 7-2013 specifies items that “shall be considered” while writing the procedures. The requirements are separated by equipment type and operating phases. Many of the requirements are the same for the various equipment types. The following is a brief overview by operating phase.

Things to consider for Initial Startup Procedures include

  • Appropriate conditions to ensure a safe startup;
  • Corrective actions for conditions outside acceptable limits;
  • Lockout/tagout procedures;
  • State of the electrical disconnect;
  • Position of isolation and service valves;
  • Lubrication systems, if required;
  • Alarm systems; and 
  • Steps to start or activate the equipment.

Things to consider for Normal Operating Procedures include verification that parameters are within expected operating ranges and troubleshooting as necessary. Things to consider for Temporary Operating Procedures include

  • Steps to consult supervisory personnel to establish temporary operating parameters,
  • Steps to modify the equipment to operate under temporary parameters,
  • Procedures to monitor the equipment while operating under temporary operating parameters, and
  • Lockout/tagout procedures.

Things to consider for Normal Shutdown Procedures include

  • Steps to stop the equipment, and
  • Steps to prepare the equipment for stand-by operation.

Things to consider for Emergency Shutdown Procedures include

  • Identification of the person responsible for emergency shutdown,
  • Steps to stop the equipment,
  • Steps to isolate the equipment from the system and remove all sources of power,
  • Notification procedures, and
  • Steps to document the cause for an emergency shutdown.

Things to consider for Emergency Operating Procedures include steps to operate the equipment under emergency operations, for example, when the equipment is operating under conditions outside of expected operating limits.

Things to consider for Startup Procedures Following Abnormal Shutdown Conditions or a Turnaround include

  • Appropriate practices if the equipment will be started;
  • Appropriate conditions to ensure a safe startup;
  • Corrective actions required if conditions are outside of expected operating limits;
  • Lockout/tagout procedures;
  • State of the electrical disconnect;
  • Position of isolation and service valves;
  • Lubrication systems, if required;
  • Alarm systems; and • Steps to start or activate the equipment.

Because there are multiple equipmentspecific items to consider, those responsible for developing and updating operating procedures are highly recommended to obtain a copy and fully review the IIAR standard.


The process of developing and implementing written operating procedures is easier when broken down into steps. Planning is key to a successful and positive project outcome. Having the right information and determining who will be involved and how the work will be completed will help ensure that the project goes smoothly and is completed in a timely manner.

The following are steps for developing and implementing operating procedures:

  1. Gather PSI,
  2. Select a format,
  3. Determine who should be involved,
  4. Write the procedure(s),
  5. Verify for accuracy,
  6. Certify the procedure(s),
  7.  Implement and provide training, and
  8. Hold people accountable.


As stated previously, having accurate process safety information is critical. Take time to verify the PSI for accuracy. Specific PSI useful for developing the procedures include

  • Safety data sheets;
  • P&ID;
  • Block flow diagrams;
  • System design capacities and control parameters;
  • U-1A forms for vessels;
  • Equipment manufacturer data reports;
  • Equipment installation, operating, and maintenance manuals; and
  • Instrumentation and control system documentation.


When selecting a format first determine how the procedures will be kept and made available to the employees. If the procedures will be kept electronically and one of the multiple online PSM safety software programs used, formatting may be constrained by the software. If utilizing standard office software, more flexibility in formatting to meet the needs of the facility may be available.

Also important is considering what information will be included within the procedure. Operating procedures have morphed over time to include two major sections: the SOP and the technical operating specifications (TOS). The SOP section includes the steps for each operating phase, and the number of operating phases that will be needed for each piece of equipment should be considered.

The TOS section will include OSHArequired information, such as (1) operating limits, including the consequences of deviation and steps to correct or avoid deviation; (2) safety and health considerations; and (3) safety systems. Additional parts of the TOS section may include (4) objectives and purpose; (5) responsibilities; (6) equipment identification and design specifications; (7) function and operation; (8) department and location; (9) applicable safe work practices; and (10) a list of related reference documents, such as operator and maintenance manuals, P&IDs, lockout/ tagout procedures, and so forth.

There are other things to consider as well. Determine how the revisions will be tracked. Will each procedure include its own revision table, or will a separate log be maintained? Will a copy of the equipment-specific P&ID be included? Whatother identifying information should be included, such as pictures, diagrams, tables, and so on?

Lastly, enlist the help of the operators. Ask them what would make the procedures easier to use and follow. Determine what would be useful and what they would consider unnecessary. Listen to their ideas and recommendations. Apply what makes sense. Not all recommendations need to be implemented, but getting the operators to participate in the process and feel fully vested in the final result is important.


The situation may largely determine who to involve in writing the procedures. If the facility has been in operation for several years, enlist the help of the experienced operators. They know the system and understand its operation. If the facility is new, the writing may be left to the engineering management team. If the business is a corporation with multiple facilities, assistance may be obtained from experienced operators at other facilities. The design contractor, installing contractor, or an experienced PSM consulting firm may also be hired. In this situation, ensure that the procedures will be provided in both hard copy and in an electronic format that can be edited. Otherwise, modifying the procedures when changes to the system and/or operation occur will be harder.


In some situations procedures from another facility can be useful for creating new operating procedures. But in most instances they cannot be adopted outright. The procedures must be tailored to the operational requirements of the specific equipment and facility.


Test the procedure. Have someone watch an operator perform the procedure to ensure it is effective. Steps may be missing, and/or steps may not be needed. If so, change the procedure and retest it. Use multiple people throughout the process to provide varying perspectives. Ensure all information necessary to perform the procedure safely and effectively is included.


Whoever is identified as the employer’s certifying official should be involved in the verification process. The certifier should formally certify the procedures once they are finalized.


Writing the procedures is not enough. The procedures must be implemented, meaning used and followed as part of the facility’s normal operation. Operators need to be trained to follow them as written. Specific information on training requirements can be found in the training requirements section later in this paper.


Finally, operators need to be held accountable to ensure they are performing the written procedures correctly. Operators who deviate from completing the procedures as written need to be counseled and disciplined if necessary.


The following are 10 simple principles for clear and concise technical writing.

Use Short Words

Avoid using capacious, incommodious, and ostentatious terminologies. When possible, use words no more than two to three syllables in length.

Use Short Sentences

Write one sentence per action step. Avoid telling the operator to open the valve and start the compressor after checking the pressure and verifying sump water levels and making sure the condenser fans and pumps are operating properly.

Use the Active Voice

Passive: “The hand expansion valve needs to be set at the minimum position for liquid flow.”

Active: “Set the liquid flow hand expansion valve to its minimum position.”

Start Action Steps with Action Verbs

Starting action steps with action verbs helps to keep sentences shorter and easier to follow. Examples include “open the…,” “check for…,” “turn the…,” “inspect for…,” and so on.

Adding an action descriptor (adverb) is acceptable, for example, “slowly open the…,” “carefully inspect for…,” and so on.

Avoid Redundancy

Planning in advance before performing the procedure is important but overstated.

Avoid Things that Are Implied

You should avoid using the word “you” as you should know you are being told the specific steps to the procedure you are performing. Substitute Wordy Phrases with Single Words Using the word “always” as a substitute for “at all times” and “if” as a substitute for “in the event of” are good examples.

Be Specific

Statements such as “after a few minutes” and “when the pressure is lower” are vague and subjective. State the number of minutes and at what pressure.

Use Smart Formatting

  • Simple fonts are easier to read than more complex fonts.
  • If everything is in bold, then nothing stands out as bold. 
  • If everything is CAPITALIZED, people will think they are being yelled at.
  • Horizontal bulleted items are more effective than long lists in paragraph form.
  • Several short paragraphs with no space between them become one long paragraph that is overwhelming and unread.

Spell Check

Enough saed.


Training follows the operating procedures element. The training element has three requirements:

  • Initial training,
  • Refresher training, and
  • Training documentation.

Employees must be trained in an “overview of the process” and the operating procedures they will be required to perform. The training must occur before the operator is required to perform the procedure. Emphasis must be placed on safety and health, emergency procedures, and applicable safe work practices. An exception exists for employees who are already involved with operating the process.

The employer can document in writing that the operator has the necessary “knowledge, skills, and abilities” to operate the system safely. This is for initial training only. The employer is required to consult with employees to determine the appropriate frequency of refresher training. Refresher training is required at a minimum every three years. However, training may be required more often to ensure that the “employee understands and adheres” to the requirements of the procedure.

As with all things OSHA related, training must be documented. Employers are required to determine whether the employee understood the training and document the method of verification, such as a written test, a verbal question and answer period, demonstration, and so forth. The documentation must include the employee’s name and date of training. Contract employees should also receive documented training when they operate systems.


State Requirements

Before developing and implementing operating procedures, verify whether your state has requirements in addition to those provided by OSHA and EPA. This may be especially relevant for states that operate under their own state plans for occupational safety and health. State plans must meet the minimum requirements of federal OSHA, but they may establish stricter regulations that the employer must follow.

Procedures for Nonroutine Tasks

Nonroutine tasks are an inevitable part of operating and maintaining an ammonia refrigeration system and include those activities that are not covered within the normal operating phases. These could include changes in system components and equipment, modifications to piping configurations, additions of new equipment and systems, repairs to piping, procedures for maintenance and repairs, and so on.

Whenever these types of procedures are performed, potential for accidents and injuries increases. Performing nonroutine tasks is inherently dangerous for several reasons. For example, these tasks usually involve opening the system, and they are dangerous because they are nonroutine and as such are not performed often and may contain several unknowns. There are human factors to account for. Intentionally or unintentionally, people are prone to error. There are various levels of competency, training, and experience. Overconfidence, distractions, inattentiveness, fatigue, and forgetfulness can lead to oversights and miscalculations. Throw in the fact that several people may be involved, and the possibilities for an unplanned incident multiply.

For these reasons developing written procedures for performing nonroutine tasks is important. Nonroutine procedures should be developed in the same way and follow the same path as standard procedures. Gather the necessary process safety information. Select the format. Determine who will help. For example, difficult pumpouts involving multiple systems may require help from an outside contractor.

Write the procedure. Verify it for accuracy. Do a dry run. Walk the system to ensure nothing was missed. Look for potential hazards, and address all concerns. Certify the procedure as accurate. Written operating procedures for nonroutine tasks are necessary for the safety of employees and a successful project outcome.

One Procedure for Multiple Equipment

A question frequently asked is, “Can like equipment be grouped into one procedure?” While the PSM standard (OSHA 1992) does not specifically address this question, OSHA does address a similar question in a letter of interpretation dated July 12, 2006. The context of the question is lockout/tagout procedures. The question asks if “generic procedures” that state “close the suction valve and discharge valve” are acceptable in lieu of actual valve numbers. OSHA provides the following response:

The lack of procedural clarity and specificity can result in employees failing to isolate the key valves, permitting exposure to the hazardous energy during the servicing or maintenance work. Simply listing valves by their functionality (such as suction valve, discharge valve, etc.) may lead to confusion and error with respect to those valves that must be closed to effectively isolate hazardous energy, due to inadequate employee direction.

While this does not answer the question directly, perspective on OSHA’s view and the importance of providing procedures that are equipment specific can be inferred. Eliminate or at least minimize any possibility for operator confusion.

Maintenance Procedure vs. Operating Procedure

Similar to operating procedures, the PSM program requires written maintenance procedures. Understanding their commonalities and differences is important. Like operating procedures, maintenance procedures must be written and implemented. Before operators are allowed to perform a maintenance procedure, they must be trained on an overview of the process and the specific procedure they will be required to perform. However, some differences include that maintenance procedures do not have to be certified annually. Furthermore, training is required only once, unlike operating procedures, which require training at a minimum every three years and more often if necessary. At the employer’s discretion, operating procedure requirements may be adopted and used for maintenance procedures.


Operating procedures provide detailed instructions on how to operate the system and its equipment safely and efficiently. They ensure that systems are operated within the manufacturers’ designed parameters and provide a systematic set of instructions for the operators to follow.

When developing and implementing operating procedures, consider the following questions:

  • Do the procedures provide clear instructions?
  • Are the procedures consistent with the available process safety information?
  • Do the procedures cover all operating phases, including the minimum required?
  • Are the procedures accurate and effective for the safe and efficient operation of the system and its components?
  • Do the procedures meet applicable regulatory requirements?
  • How will the procedures be used and followed?
  • How will the procedures be kept current?

To be effective, operating procedures must be properly written, implemented, followed, and kept current. Written procedures not only satisfy regulatory compliance but provide a multitude of other benefits for the company and the operators


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  2. EPA (Environmental Protection Agency). (2009). “General guidance on risk management programs for chemical accident prevention (40 CFR PART 68).” Washington, D.C.: EPA.
  3. IIAR. (2013). “Developing operating procedures for closed-circuit ammonia refrigeration systems.” ANSI/IIAR 7-2013. Alexandria, VA: IIAR.
  4. IIAR. (2012). Process Safety Management & Risk Management Program Guidelines.Alexandria, VA: IIAR.
  5. OSHA (Occupational Safety and Health Administration). (1994). “Highly Hazardous Chemicals as it applies to operating procedures and certify on an annual basis.– [1910.119].” Letter of interpretation, March 9. Washington, D.C.: OSHA.
  6. OSHA (Occupational Safety and Health Administration). (2006). “PSM compliance for ammonia refrigeration systems.–[1910.38; 1910.119; 1910.119(d)(3)(i); 1910.119(d) (3)(ii); 1910.119(e) (3); 1910.119(j)(6)(i); 1910.119(j)(6)(ii); 1910.119(k) (2); 1910.119(l)(2)(i); 1910.119(l)(4); 1910.119(l)(5); 1910.119(m)(3); 1910.119(o)(1); 1910.120; 1910.134; 1910.147; 1910.147(c)(4)(ii)].” Letter of interpretation, July 12. Washington, D.C.: OSHA.
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  8. OSHA (Occupational Safety and Health Administration). (2017). U.S. Department of Labor-OSHA “CHEM NEP Update – Industry Outreach (presentation).” Washington, DC, June 7, 2017.