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Course 736 - Introduction to Process Safety Management

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Process Safety Information

Developing the Written PSM Plan

Employers must compile written process safety information before conducting any process hazard analysis required by the standard. The written process safety information will help the employer and the employees involved in operating the process to identify and understand the hazards posed by those processes that involve highly hazardous chemicals.

To develop an effective PSM program and Process Hazard Analysis (PHA), it is important to develop and maintain complete and accurate written information.
To develop an effective PSM program and Process Hazard Analysis (PHA), it is important to develop and maintain complete and accurate written information.

To develop an effective PSM program and Process Hazard Analysis (PHA), it is important to develop and maintain complete and accurate written information on each of the following:

  1. process chemicals,
  2. process technology, and
  3. process equipment

This information will be used by:

  • the team performing the process hazard analysis;
  • those developing the training programs and the operating procedures;
  • contractors whose employees will be working with the process;
  • those conducting the pre-startup reviews;
  • local emergency preparedness planners and insurance and enforcement officials.

Hazards of the Chemicals Used in the Process

To develop an effective PSM program and Process Hazard Analysis (PHA), it is important to develop and maintain complete and accurate written information.

The information about the chemicals, including process intermediates, needs to be comprehensive and accurate. Information on the hazards of the highly hazardous chemicals in the process shall consist of at least the following:

  • Toxicity
  • Permissible exposure limits
  • Physical data
  • Reactivity data
  • Corrosivity data
  • Thermal and chemical stability data
  • The hazardous effects of inadvertent mixing of different materials

Current safety data sheets (SDS) can be used to help gather information about hazardous chemicals, but it must be supplemented with process chemistry information, including runaway reaction and over-pressure hazards, if applicable.

Technology of the Process

To develop an effective PSM program and Process Hazard Analysis (PHA), it is important to develop and maintain complete and accurate written information.

Process technology information is a part of the process safety information package and should include employer-established criteria for:

  • maximum inventory levels for process chemicals;
  • limits beyond which would be considered upset conditions; and
  • a qualitative estimate of the consequences or results of deviation that could occur if operating beyond the established process limits.

Information on the technology of the process must include at least the following:

  • A block flow diagram or simplified process flow diagram,
  • Process chemistry,
  • Maximum intended inventory,
  • Safe upper and lower limits for such items as temperatures, pressures, flows or compositions, and
  • An evaluation of the consequences of deviations, including those affecting the safety and health of employees.

Where the original technical information no longer exists, information may be developed in conjunction with the process hazard analysis in sufficient detail to support the analysis.

Note: Safety Data Sheets (SDSs) meeting the requirements of the Hazard Communication Standard (20 CFR 1910.1200) may be used to comply with this requirement to the extent they contain the required information.

Example of a Block Flow Diagram
Example of a Block Flow Diagram
Click to enlarge

Block Flow Diagrams

A block flow diagram can be used to show the major process equipment and interconnecting process flow lines and flow rates, stream composition, temperatures, and pressures when necessary for clarity. The block flow diagram is a simplified diagram.

Process Flow Diagrams

pipinginstrument
Process Flow Diagram
Click to enlarge

Process flow diagrams are more complex and show all main flow streams including valves to enhance the understanding of the process as well as pressures and temperatures on all feed and product lines within all major vessels and in and out of headers and heat exchangers, and points of pressure and temperature control.

Also, information on construction materials, pump capacities and pressure heads, compressor horsepower, and vessel design pressures and temperatures are shown when necessary for clarity.

In addition, process flow diagrams usually show major components of control loops along with key utilities.

Equipment in the Process

pipinginstrument
Piping and Instrument Diagrams
Click to enlarge

Piping and instrument diagrams (P&IDs) may be used to describe the relationships between equipment and instrumentation as well as other relevant information that will enhance clarity.

Computer software programs that create P&IDs or other diagrams useful to the information package may be used to help meet this requirement.

Information on the equipment in the process must include the following:

  • materials of construction;
  • piping and instrument diagrams (P&IDs);
  • electrical classification;
  • relief system design and design basis;
  • ventilation system design;
  • design codes and standards employed;
  • material and energy balances for processes built after May 26, 1992; and
  • safety systems (e.g., interlocks, detection, or suppression systems).

Equipment in the Process (Continued)

The employer must document that equipment complies with recognized and generally accepted good engineering practices.

For existing equipment designed and constructed in accordance with codes, standards, or practices that are no longer in general use, the employer must determine and document that the equipment is designed, maintained, inspected, tested, and operated in a safe manner.

Compiling and maintaining this information is important to:

pipinginstrument
  • To provide the basis for identifying and understanding the hazards of a process
  • To develop the process hazard analysis
  • Comply with other provisions of PSM such as management of change and incident investigations.

For existing equipment designed and constructed many years ago the employer must:

  • document which codes and standards were used
  • certify that the design and construction along with the testing, inspection, and operation are still suitable for the intended use.

Where the process technology requires a design that departs from the applicable codes and standards, the employer must document that the design and construction are suitable for the intended purpose.

Instructions

Before beginning this quiz, we highly recommend you review the module material. This quiz is designed to allow you to self-check your comprehension of the module content, but only focuses on key concepts and ideas.

Read each question carefully. Select the best answer, even if more than one answer seems possible. When done, click on the "Get Quiz Answers" button. If you do not answer all the questions, you will receive an error message.

Good luck!

1. To develop an effective PSM program and Process Hazard Analysis (PHA), it is important to develop and maintain complete and accurate written information on each of the following, EXCEPT:

2. Information on the hazards of the highly hazardous chemicals in the process shall consist of at least which of the following?

3. Under the PSM Program, current safety data sheets (SDS) can be used to help gather information about hazardous chemicals.

4. A __________can be used to show the major process equipment and interconnecting process flow lines and flow rates, stream composition, temperatures, and pressures when necessary for clarity.

5. Where the process technology requires a design that departs from the applicable codes and standards, the employer must do which of the following?


Have a great day!

Important! You will receive an "error" message unless all questions are answered.