By HSP (Ref: Chemical Process Safety, Roy E Sander)
The OSHA Process Safety Management (PSM) standard should be reviewed to properly develop an MOC procedure. The PSM section addressing “Management of Change” is found in paragraph (l ) of OSHA 1910.119 and states:
- The employer shall establish and implement written procedures to manage changes [except for “replacements in kind”] to process chemicals, technology, equipment and procedures; and changes to facilities that affect a covered process.
- The procedures shall assure that the following considerations are addressed prior to any change.(i) The technical basis for the proposed change; (ii) Impact of change on safety and health; (iii) Modifications to operating procedures; (iv) Necessary time period for the change; and, (v) Authorization requirements for the proposed change.
- Employees involved in operating a process and maintenance and contract employees whose job tasks will be affected by a change in the process shall be informed of, and trained in, the change prior to startup of the process or affected part of the process.
- If a change covered by this paragraph results in a change to the process safety information required by paragraph (d) of the section shall be updated accordingly.
- If a change covered by this paragraph results in a change to the operating procedures or practices required by paragraph (f ) of this section, such procedures or practices shall be updated accordingly.
The standard also defines “replacement in kind” as a replacement that satisfies the design specification. Appendix C to OSHA 1910.119 is entitled “Compliance Guidelines and Recommendations for Process Safety Management (Nonmandatory).” It serves as a nonmandatory guideline to assist with complying to the standard.
“Managing Change.” To properly manage change to process chemicals, technology, equipment and facilities, one must define what is meant by change. In this process safety management standard, change includes all modifications to equipment, procedures, raw materials and processing conditions other than “replacement in kind.” These changes need to be properly managed by identifying and reviewing them prior to implementation of the change. For example, the operating procedures contain the operating parameters (pressure limits, temperature ranges, flow rates, etc.) and the importance of operating within these limits. While the operator must have the flexibility to maintain safe operation within the established parameters, any operation outside of these parameters requires review and approval by a written management of change procedure.
Management of change covers such as [sic] changes in process technology and changes to equipment and instrumentation. Changes in process technology can result from changes in production rates, raw materials, experimentation, equipment unavailability, new equipment, new product development, change in catalyst and changes in operating conditions to improve yield or quality. Equipment changes include among others change in materials of construction, equipment specifications, piping pre-arrangements, experimental equipment, computer program revisions and changes in alarms and interlocks. Employers need to establish means and methods to detect both technical changes and mechanical changes.
Temporary changes have caused a number of catastrophes over the years, and employers need to establish ways to detect temporary changes as well as those that are permanent. It is important that a time limit for temporary changes be established and monitored since, without control these changes may tend to become permanent. Temporary changes are subject to the management of change provisions. In addition, the management of change procedures are used to insure that the equipment and procedures are returned to their original or designed conditions at the end of the temporary change. Proper documentation and review of these changes is invaluable in assuring that the safety and health considerations are being incorporated into the operating procedures and the process. Employers may wish to develop a form or clearance sheet to facilitate the processing of changes through the management of change procedures. A typical change form may include a description and the purpose of the change, the technical basis for the change, safety and health considerations, documentation of changes for the operating procedures, maintenance procedures, inspection and testing, P&IDs, electrical classification, training and communications, pre-startup inspection, duration if a temporary change, approvals and authorization.
Where the impact of change is minor and well understood, a check list reviewed by an authorized person with proper communication to others who are affected may be sufficient. However, for a more complex or significant design change, a hazard evaluation procedure with approvals by operations, maintenance, and safety departments may be appropriate. Changes in documents such as P&IDs, raw materials, operating procedures, mechanical integrity programs, electrical classifications, etc. need to be noted so that these revisions can be made permanent when the drawings and procedure manuals are updated.
Copies of process changes need to be kept in an accessible location to ensure that design changes are available to operating personnel as well as to PHA team members when a PHA is being done or one is being updated.
The AIChE’s Center for Chemical Process Safety developed a “how to” type of book that addresses most of the concerns of OSHA’s proposed Process Safety Management standard and all of the concerns of Management of Change. This book is useful to the front-line supervisor, the second-level supervisor, superintendent, and the manager of a facility that manufactures, handles, or stores hazardous chemicals. It is for the “on-site” organization that is developing the specific procedures of a Management of Change (MOC) program.
Plant Guidelines for Technical Management of Chemical Process Safety (1992) provides contributions from many participating chemical manufacturers. There are numerous checklists, decision trees, proposed forms, apparently provided by various chemical plants who had an established MOC program. The Chemical Manufacturers Association (CMA) contracted with JBF Associates, Inc., to develop A Manager’s Guide to Implementing and Improving Management of Change Systems. This 100-page booklet, published in 1993, was not intended to be a cookbook, but rather a general guide to define the important features of MOC systems.