Hazardous Area Electrical Work in the NT: What Site Owners Need to Know

If your site stores or handles fuel, gas or combustible dust, “hazardous area” isn't a label you get to skip past. It's the starting point for every electrical decision on site: what equipment goes in, where it goes, and how often it gets checked. Here's what TEC Automation gets asked most often.

What actually makes an area “hazardous” from an electrical perspective?

It comes down to one question: could an electrical source, like a spark, a hot surface or a fault, set something alight? That's different from a chemical hazard, like a corrosive spill. Electrical hazardous area work is about ignition risk from fuel vapours, flammable gases and combustible dust. It's not about handling or spillage, like a chlorine or fluoride leak. Those come under separate chemical safety rules.

Working out whether a site needs hazardous area classification is a job for a hazard assessment, usually led by an engineer. TEC Automation supports the electrical side of that assessment, and the paperwork that goes with it.

What NT sites typically need hazardous area classification?

• Fuel storage and distribution: diesel, petrol, aviation fuel, including temporary or portable tanks left in a fixed position long enough to function as permanent storage

• Gas handling and dosing sites, including water treatment plants using chlorine gas

• Sites with combustible dust, common in mining, grain and some manufacturing environments

• Defence and critical infrastructure fuel farms and distribution points

What does “Ex rated” actually mean?

Ex is short for explosion protected. An Ex-rated device is built so sparks or heat inside it can't reach the air around it. That might mean a sealed enclosure, a flameproof housing, or a circuit designed to never carry enough energy to cause ignition. Which Ex rating a device needs depends on the zone it's going into, so zone and Ex rating always get decided together, not separately.

How do zone classifications work?

Under AS/NZS 60079.10.1, areas with flammable gas or vapour get a zone rating: Zone 0, 1 or 2. It depends on how often, and for how long, an explosive atmosphere could be present. Zone 0 means it's there almost all the time. Zone 2 means it's unlikely, and only brief if it happens. Combustible dust areas use a similar system under AS/NZS 60079.10.2: Zone 20, 21 and 22.

A zone doesn't have to cover the whole room. A fuel bowser might only need a small Zone 1 area right at the nozzle, with a wider Zone 2 a few metres around it. A high-roofed shed storing the same fuel further away might not need Ex-rated fittings up near the ceiling at all. That's fine, as long as the zone boundaries are worked out correctly and the storage doesn't move.

What's a hazardous area register (or “dossier”) and why does it matter?

Every piece of electrical equipment in a classified hazardous area gets recorded, down to the serial number, in a hazardous area register. On site, this is sometimes called a verification dossier. It follows AS/NZS 60079.14 and AS/NZS 60079.17. Swap a part for an identical one, and the register just needs a serial number update. Change the product type, or how a cable enters the device, and the whole entry needs re-checking. Skip that step, and the equipment's Ex certification is no longer valid, whether anyone's noticed or not.

What happens if hazardous area work isn't done properly?

The immediate risks are ignition, explosion and loss of life. That's not an exaggeration, it's the reason the classification system exists in the first place. But the more common job TEC Automation actually gets called in for is a second-round fix. A previous contractor understood the basics, but not the documentation or verification side. So the equipment has to be re-checked, re-sealed where needed, and the register rebuilt, all at extra cost, on top of the original job.

How often does hazardous area equipment need maintenance?

It depends on the hazard rating and how the equipment gets used, not a single fixed schedule. Higher-risk zones and busier sites need more frequent visual checks. Fuel distribution points with lots of outside contractors coming and going are a good example, since the risk isn't just the equipment, it's also what an unfamiliar contractor might do around it. Storage areas holding higher-risk substances need regular checks on their earthing systems too. Static build-up is a real way fires can start, especially in the NT's dry season, when static discharge is more likely.

What does TEC Automation bring to Defence and critical infrastructure sites?

Fuel farms at sites like RAAF Darwin and RAAF Tindal come with an extra layer of scrutiny on top of standard NT compliance. Think site access protocols, security requirements and Defence-specific paperwork. TEC Automation's experience here includes calibrating level, pressure and flow sensors right across a site. This work has to be precise, since the readings are used to bill fuel usage between organisations.

Who enforces hazardous area compliance in the NT?

WorkSafe NT is the regulator for electrical safety in the Territory, including hazardous area work, under the Electrical Safety Act 2022 and Electrical Safety Regulations 2024. Unlike fire compliance, most sites don't get routine inspections. Non-compliance often goes unnoticed until something happens, unless a site is prominent enough that questions get asked. That gap is exactly why an independent hazardous area audit is worth having before something goes wrong, not after.

Can TEC Automation review a site that isn't sure if it needs classification?

Yes, this is one of the most common ways clients start working with TEC. An audit looks at what's being stored, how it's stored, and whether the existing electrical equipment and documentation matches the actual risk on site, including sites that assumed they were low-risk and never checked.

Recent hazardous area experience

• Defence fuel infrastructure: site-wide instrument calibration across level, pressure and flow sensors used for fuel storage and distribution measurement at a Defence airbase, supporting accurate recording for fuel usage billing.

• Earthing and static control: testing and recording of earthing systems on fuel storage tanks across Darwin and RAAF Tindal (near Katherine, where TEC holds an ongoing maintenance contract), reducing ignition risk from static build-up in the Territory's dry conditions.

• Site auditing: hazardous area review for a remote Katherine mining operation to confirm classification requirements for underground infrastructure.

TEC Automation operates across Darwin, Katherine, Tennant Creek and remote NT locations. Get in touch to talk through your hazardous area compliance status.

Phone: (08) 8968 9484 | Email: info@tecautomation.com.au