• Home
  • /
  • PHA and HAZOP

When do you need a PHA - HAZOP ?

Process Hazard Analysis (PHA) is required for all industrial-scale plants that store or process flammable, toxic or environmentally hazardous materials. HAZID - hazard identification and HAZOP - hazard and operability studies, are a common method for completing PHA using a multi-discipline team.

  • New projects or developments
    Projects with a potential for hazards to people or the environment need to conduct PHA by some method. HAZID can be applied in the early stages, and HAZOP is commonly applied when detailed P&ID drawings are available.
  • Existing process plants that store and process hazardous materials
    Depending where you are in the world, there may be slightly different local standards or requirements for the frequency of reviews. Most companies review HAZOP studies at least every five years, even when major changes have not occurred.
  • Plant modifications and upgrades
    Any plant modifications or upgrade must complete PHA on the proposed change.

Frequently Asked Questions about PHA and HAZOP

What is a PHA?

Process hazards analysis (PHA) is a general term used in the process industry sector for any kind of study that identifies hazards and potential sources of harm to people, environment and assets. A PHA can be done in many different ways.

What is a HAZOP?

HAZOP is short for a Hazard and Operability Study. This is a systematic technique used to identify hazards, consequences and safeguards for industrial processes.

When is the best time to do a HAZOP?

The timing of a HAZOP can vary, but it is often best approached when there is sufficient design information; when piping and instrumentation diagrams are available with a meaningful level of detail.

Who should get involved with HAZOP?

  • The duty holder should get someone experienced to lead the HAZOP activity and record team findings.
  • Plant operators and maintenance personnel.
  • Process experts.
  • Electrical, control and instrumentation.
  • Process safety / HSE representative.

Is LOPA part of HAZOP?

Layer of Protection Analysis (LOPA) can be combined with a HAZOP study provided this is decided in advance. LOPA takes selected HAZOP scenarios and determines the effectiveness of safeguards as truly independent protection layers (IPL).



eFunctionalSafety has completed many HAZOP studies followed by Layer Of Protection Anlaysis (LOPA).

With our experienced leaders and specialist recording software, we can support your team to evaluate the hazards and risks posed by practically any industrial process or machine.

Contact Us for a Quotation

Select an option, then fill out your details
Please Select One
  • General PHA advice / enquiry
  • HAZOP Stage 3 - P&ID's available
0 of 350

PHA / HAZOP Preparation

A PHA/HAZOP will only commence when you have suitable procedures and planning in place.

We provide the support to ensure your PHA/HAZOP is prepared in advance of valuable team-member time being spent in meetings.

New projects, modifications or revalidation

PHA/HAZOP and LOPA can be completed on any new-build project with sufficient design information to proceed.

Plant modifications need to undergo re-HAZOP when there are changes that can affect outcome consequences and when any protection layer is altered.

Revalidaiton of PHA/HAZOP is recommended at least once every 5 years.

Success message!
Warning message!
Error message!