Please Wait...


Questions of the Week

Primatech posts weekly questions relating to various aspects of safety, security and risk on the home page of our website together with answers to provide visitors with the opportunity to test and improve their knowledge of these subjects. This page contains questions and answers that have appeared in previous weeks.

What is a safety culture assessment?

A survey to help an organization identify pervasive attitudes or beliefs regarding risk tolerance in the workplace. It is conducted to provide a basis for improving the safety culture.

Does a PHA scribe need to have a technical background?

Ideally, a scribe should be technically-oriented. They need a knowledge of processes in order to understand the discussions that occur during PHA studies. Also, they need to understand the process that is followed in performing a PHA study and be familiar with the technical terms and acronyms used. Sometimes, the role is filled by a junior engineer, although administrative personnel with appropriate experience also have acted successfully as scribes.

What is meant by safety culture?

Values, beliefs, perceptions and attitudes that shape behaviors exhibited towards safety within an organization. Put simply, factors that influence how people in an organization behave with respect to safety when no one is watching.

Should a PHA team leader act as their own scribe?

Many PHA team leaders act as their own scribe. Use of PHA recording software gives leaders a subtle but powerful form of control over the team. They can direct the team's attention to highlighted entries in the worksheet and readily display checklists and other documents. Of course, leaders who scribe should have reasonable keyboard skills and be comfortable with all the other responsibilities of leading studies so that scribing does not impair their performance as a leader.

Should PHA worksheet entries for nodes be completed in a particular order?

Node order typically follows the primary process flow. Side streams are addressed as they are encountered.

What is meant by node intention?

Node intention defines relevant aspects of the process design intent for each node, for example, safe ranges of operating parameters. Node intentions and parameter intentions often are defined in ranges (e.g. 100 to 150 gpm, or 20% to 80% tank fill height).

Is it acceptable for the owner of a PHA study to make changes to the PHA to account for issues missed by the team, for example, omitted safeguards?

No. The owner cannot know all the implications of the change. The PHA team should be reconvened to discuss the change and modify the PHA accordingly.

Is pre-populating PHA worksheets with scenario information by the PHA facilitator an acceptable procedure?

No. Scenario identification depends on team members contributing their respective knowledge of the process and brainstorming scenarios together.

What type of hazardous consequences should I address in a PHA?

OSHA and EPA process safety regulations address the consequences of catastrophic releases of toxic, reactive, flammable, or explosive chemicals that may result in toxic, fire or explosion hazards. OSHA's regulation addresses impacts on employees in the workplace including contractors. EPA's regulation addresses impacts on the public and the environment. Other types of consequences, such as business loss, property damage, loss of production, harm to business reputation, etc. are evaluated at the discretion of company management.

My site is a small chemical plant with a limited number of employees. What is the minimum number of people that must be on my PHA team?

OSHA and EPA process safety regulations require that PHA be performed by a team with expertise in engineering and process operations, and the team must include at least one employee who has experience and knowledge specific to the process being evaluated. Also, one member of the team must be knowledgeable in the specific PHA method being used. For a small company, roles may be combined, such as the person with process or engineering experience also being the PHA facilitator. However, the PHA team should consist of at least three people at a minimum, and preferably more, in order to ensure that brainstorming and meaningful discussions are possible during the study sessions.

Plants with limited personnel may wish to perform PHA studies for a few hours each day for a few days each week. This approach requires longer to complete PHA studies but lessens the daily time burden on team members.