Safer equipment decisions
Relate classified zones, gas or dust groups and temperature requirements to equipment selection.
Safety Zest · EHS Consulting
Hazardous Area Classification Study
Define where explosive atmospheres may occur so electrical equipment selection and ignition-control decisions are based on documented engineering inputs.
Site-specific scopePractical deliverablesPan-India support
Service overview
What is Hazardous Area Classification Study?
Hazardous Area Classification (HAC) is an engineering study used where flammable gases, vapours, mists or combustible dusts may be released. It evaluates the sources and frequency of release, material properties, ventilation and operating conditions to define zones in which special ignition controls and appropriately rated equipment are required. Gas and vapour areas are commonly expressed as Zones 0, 1 and 2; dust areas as Zones 20, 21 and 22.
Business and safety value
How does this service benefit your organisation?
Controlled ignition risk
Identify where electrical and non-electrical ignition sources require focused management.
Clear engineering record
Create drawings, schedules and assumptions that projects, operations and maintenance can reference.
Change-management baseline
Provide a documented basis for reviewing later process, ventilation or layout changes.
Our approach
How Safety Zest delivers the service
Safety Zest works with client process, electrical and EHS personnel to define the study boundary and obtain reliable design and operating data. Specialists identify credible release sources, assess release grades and ventilation, determine zone type and extent using the applicable project criteria, and prepare marked-up drawings and schedules. Findings are reviewed with the client before issue so assumptions, unresolved data gaps and equipment implications remain visible.
Before work starts, the proposal identifies the locations, interfaces, inputs, deliverables and exclusions. This keeps expectations clear and helps the client arrange access to the right people and records.
Included activities
Typical scope of work
| Workstream | What it covers |
|---|---|
| Process basis | Materials, flash points, lower explosive limits, operating pressure and temperature, and release scenarios. |
| Release sources | Flanges, vents, drains, sampling points, seals, openings, transfer points and dust-handling equipment. |
| Environmental factors | Indoor or outdoor location, ventilation availability and effectiveness, congestion and physical barriers. |
| Classification output | Zone type, extent, gas or dust group, temperature-class considerations and supporting notes. |
| Equipment review | High-level comparison of installed equipment information with classification requirements, when included. |
Delivery method
A clear five-step process
- 1Scope
Confirm applicable standards, project criteria, battery limits and required deliverables.
- 2Review
Collect and validate process data, layouts, ventilation information and equipment details.
- 3Assess
Conduct a site survey or design review to identify sources of release and local conditions.
- 4Develop
Calculate or determine zone classification and extent, recording assumptions and limitations.
- 5Deliver
Prepare drawings and schedules, review them with stakeholders and issue controlled deliverables.
Outputs
What you receive
- Hazardous area classification basis and methodology note
- Source-of-release register and classification schedule
- Zone drawings for gas/vapour and/or combustible-dust hazards
- Gas or dust group and temperature-class considerations
- Observations on apparent equipment suitability where included
- Recommendations, assumptions, exclusions and data-gap register
Connected support
Related Safety Zest services
Frequently asked questions
Questions about hazardous area classification study
When is a hazardous area classification study needed?
It is relevant where flammable gases, vapours, mists or combustible dusts are produced, stored, transferred or could be released. It may be required for a new design, an expansion, a major change or review of an existing facility.
What is the difference between Zones 0, 1 and 2?
They represent differing expectations for the presence of an explosive gas atmosphere: continuously or for long periods, likely in normal operation, or not likely in normal operation and only briefly if it occurs. Exact application follows the adopted standard and study data.
Can the study be completed from drawings alone?
A design-stage study may rely on verified documents. Existing facilities usually benefit from a site survey because ventilation, openings, equipment and release points may differ from records.
Does HAC certify all installed electrical equipment?
Not automatically. Classification defines the hazardous zones and technical requirements. Detailed equipment inspection or certification verification is a separate scope unless expressly included.
When should the classification be updated?
Review it after changes to materials, operating conditions, ventilation, release points, buildings or process layout, and when the governing design basis or applicable requirements change.
Plan the right scope
Talk to Safety Zest about your site
Share your facility type, location, timeline and immediate concern. We will help define a focused scope and the information needed for a useful proposal.
