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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.

Are railroad cars and tractor trailers containing more than the threshold quantity of a highly hazardous chemical and which remain in a facility for a period of time covered under 1910.119?

Commercial railroad tank cars and commercial tank motor vehicles (CTMVs) when remaining on a worksite and used to store threshold quantities or greater amounts of specified HHCs are covered by the PSM standard. They are covered by the PSM standard to the extent that they are not covered another regulatory authority. For example, the Hazardous Material Regulations of the Department of Transportation (DOT) (see 49 CFR Subchapter C and particularly, Part 177-Carriage by Public Highway) cover CTMVs. These DOT regulations cover cargo tank design, construction, maintenance (including repairs) and certain operations of CTMVs. Generally speaking if the cars are considered "in transit" by DOT, OSHA will defer jurisdiction to DOT.

Does OSHA require the use a risk matrix when conducting a PHA?

OSHA 1910.119 is a performance-oriented standard and does not require use of a risk matrix. However, in a letter of interpretation, OSHA suggested that the use of a risk matrix would meet the requirement in the standard that PHA address, "A qualitative evaluation of a range of the possible safety and health effects of failure of controls on employees in the workplace".

What type of communication should be provided to affected personnel after a PHA is completed?

  • Basic guidelines for communicating PHA results are:
    • Provide proactive communication
    • Access to PHA reports alone is not sufficient
    • Tailor the communication to the audience
      • Provide information that is relevant to their job, e.g. for operators and mechanics
    • Provide information on:
      • Hazard scenarios found
      • Recommendations to be implemented

Is there an advantage to adding an Intermediate Events column to a PHA worksheet template?

It can be useful to add such a column to a PHA worksheet for several reasons including:

  • Helps to avoid confusion over entries in the "Consequences" column when there are multiple consequence entries to be recorded for a scenario.
  • Provides a cleaner, more organized worksheet.
  • Useful when LOPA studies are planned.

Should my process control system be counted as a safeguard?

It may be considered as a safeguard but care should be exercised in how much credit is taken, since the basic process control system is a fundamental part of the process and PHA scenarios are often based on a control system failure as an initiating event

How can a PHA team determine which safeguards should be credited in a PHA scenario?

  • Safeguards should be qualified before being entered into the PHA worksheet for a scenario and it is a good practice to use criteria to accomplish this qualification. Suggested criteria for qualifying safeguards include:
    • Reliability: Will it work in the scenario being considered?
    • Adequacy: Is it enough to help reduce the scenario consequences?
    • Applicability: Does it really apply and is it directly applicable?
    • Effective: Does it adequately accomplish its purpose?
    • Functionality: Is it inactive or removed? Is it or can it be easily bypassed or disabled?

What are some ways PHA team leaders can avoid getting pulled into the fray?

  • Do not lead studies where they have a vested interest in the outcome or are not impartial
  • Avoid leading studies on processes for which they are a technical expert or have day-to-day responsibilities
  • Ask the scribe or another team member to alert them if it happens

What are some uses of a PHA study report?

  • Follow-up on study recommendations
  • Provides proof that the study was conducted
  • Reference by stakeholders
  • Review by persons or organizations that have a legitimate interest in the PHA
  • Auditing
  • Revalidation of the study
  • Management of change reviews

What factors largely determine whether a replacement PHA or a revised PHA is done?

  • The number of process changes that have been made and the extent of the process operations that the changes impact.
  • New requirements (federal, state, or local) and omissions / deficiencies found in the previous PHA.

What types of PHA revalidation may be completed?

Endorse - No modifications are needed to the previous PHA and a simple letter is added to the file stating that no changes have been made.

Revision – The previous PHA is modified to account for the changes that have occurred since the last PHA. The modification may be done by updating / revising the original PHA worksheets or by generating an addendum to the previous PHA that documents the changes and their impact of the previous PHA.

Replacement – The team generates a new PHA as if it were an initial PHA (some companies refer to this type of revalidation as a "clean sheet"or "re-do" PHA).