Protecting Your People: A Guide to Process Hazard Analysis (PHA) and Safety

The Process Hazard Analysis, or PHA, is an organized systematic approach of identifying, evaluating, and controlling the hazards of processes involving highly hazardous chemicals. The employer is required to complete an initial PHA using a methodology that aligns with the complexity of the process. First, employers must determine, prioritize, and document the processes to be analyzed. They may consider such things as the extent of the process hazards, the number of potentially affected employees, the age of the process, and the operating history of the process. OSHA lists a series of approved methods for employers to choose from to determine and evaluate the hazards. We won't go into them here as they won't mean much unless you're already familiar with them. OSHA 3133, Process Safety Management Guidelines for Compliance, available on the OSHA website, discusses each of the available methods. Regardless of the method used, the PHA must cover the hazards of the process, the identification of any previous incident with potentially catastrophic consequences, facility siting, also known as a risk assessment, and and human factors. It must also include the engineering and administrative controls of the hazards and their interrelationships. For instance, this might include how the company will use appropriate early detection methods such as process monitoring and control instruments with alarms and sensors to trigger interlocks or safety relays. Analysis must also include the consequences when controls fail, as well as qualitative evaluation of potential health and safety effects on employees. OSHA recommends that a team perform the PHA, including those with expertise in engineering and process operations, along with at least one member with experience and knowledge of the actual process being examined and one with expertise in the analysis method being used. The PHA process alone isn't enough, though. The employer is also required to have a system in place to address the team's findings and recommendations quickly to ensure timely resolution. Document the actions to be taken, including a written schedule of when they'll be taken. Complete actions as soon as possible and communicate these actions to operations, maintenance, and other employees involved in the process and who may be affected by the actions. The PHA must be updated and revalidated at least every 5 years by a team that meets the same requirements. The idea is to make sure the analysis is consistent with the current process. The PHA updates and documented resolutions must be kept on file and available to OSHA on request for the life of the process. The next section is an in-depth look at how to incorporate this analysis and record keeping into the actual work. That's right, we're going to look at how to put all this into practice.