Discover what preliminary hazard analysis (PHA) is, how it differs from a Work Permit (WP), when it is mandatory, and how to prepare one step by step.
By: Guilherme Herker
In the industrial environment, anticipation is the best defense against accidents. Before any equipment is turned on or a worker begins a critical activity, it is necessary to map all variables that could go wrong to protect the physical integrity of the team.
In this article, we explain how risk analysis works, when it is mandatory under Regulatory Standards (NRs), and what its direct connection is to releasing activities on the work fronts.
The Preliminary Risk Analysis (PRA) is a technical planning document focused on prevention. It is a prior and detailed study that divides a service into steps, identifies the hazards of each, and establishes which preventive measures (PPE, EPCs, and procedures) must be adopted to neutralize the chances of accidents and occupational diseases even before the workforce is mobilized.
It is very common to confuse the PRA with the Work Permit (WP), as both are mandatory tools in Health, Safety, and Environment (HSE) management. However, they represent different stages of the same preventive process.
While the PRA is the theory and planning, the WP is the authorization in practice. See the difference:
| Criterion | Preliminary Risk Analysis (PRA) | Work Permit (WP) |
|---|---|---|
| What is it? | Prior study detailing the risks of the service. | Checklist and formal authorization for execution. |
| When is it done? | Before the service is scheduled and started. | Immediately before the service, at the task location. |
| Objective | Instruct the team on how the service should be performed. | Attest that the PRA measures have been met in practice. |
Preliminary risk analysis is not required for routine office tasks or activities with negligible risk. It is a legal obligation imposed by several Regulatory Standards (NRs) whenever the operation involves non-routine or highly critical work.
The rigorous structuring of a PRA is essential, for example, in the following scenarios:
For the PRA to be a real protection tool and not just bureaucracy, it must be developed jointly by the Occupational Safety sector and the operational leaders. The process involves four steps:
The meticulous planning built into the Preliminary Risk Analysis (PRA) only has value if its guidelines are effectively executed in the field. Once the study is ready and the team is guided, it is necessary to perform a rigorous check on the work front, minutes before starting the activities, to ensure that the environment is safe.
It is exactly in this bridge between planning and "hands-on" execution that the most critical document of the operation enters: the Work Permit (WP).
To understand how this preventive flow is completed and what the role of each professional is in this final authorization, we invite you to read our article on: What is a Work Permit (WP)?.
Discover what Regulatory Standards are, how many NRs are currently in force in Brazil, and get an overview of the main EHS standards.
Understand what NR 23 is, the fire protection standard, its requirements for escape routes and its relationship with the state AVCB in occupational safety.
Understand what NR 01 is, the foundational occupational safety standard, and how the Occupational Risk Management (GRO) guidelines affect your operation.
Understand the challenge of unifying the safety culture when outsourcing services, and how to bring contractors' workers into your EHS routines.
Understand what the CA (Approval Certificate) for PPE is, how to look it up at the Ministry of Labour, and the advantages of digital PPE control.
Understand what NR-18 is, the replacement of the PCMAT by the PGR, the requirements for the construction site, and how to manage safety in construction.
Simplify your Risk Management, reducing liabilities and ensuring safe, standardized, and auditable operations with fast implementation and advisory support.
