A hazardous area lighting audit is a structured check that every luminaire in your classified areas has the right certification, is in sound physical condition, and suits the zone it sits in. To run one, gather your area classification drawings, tag every fitting, verify its Ex markings against the zone, inspect it physically, then record and fix what you find.
Lighting is often the largest group of electrical equipment in a classified area, which is why small faults pile up there unnoticed. A cracked lens, a missing blanking plug or a fitting swapped during a shutdown can quietly turn compliant hazardous lighting into an ignition risk. This guide walks through the audit the way a site electrician would actually do it.
How Do You Audit Hazardous Area Lighting?
Start with the zone classification drawings, then walk the site and list every luminaire. Check each fitting's Ex marking, certificate number, gas group and temperature class against its zone. Inspect enclosures, seals, glands and earthing, then log defects, rank them by risk, and schedule corrections and the next inspection.
What a Hazardous Area Lighting Audit Covers
A hazardous area lighting audit is a documented review of luminaires, fittings and cabling installed where flammable gas or vapour may be present. It confirms the equipment is certified, correctly selected, properly installed and still intact.
In practice, it follows the inspection grades in IEC 60079-17: visual checks from the ground, close inspection with access equipment, and detailed inspection that may involve opening enclosures. In Australia the standard is adopted as AS/NZS 60079.17, so confirm which edition your site is held to. Keep in mind that IECEx is a certification scheme for equipment, not an inspection rule, which catches plenty of people out.
Zone 1 and Zone 2: What Changes for Lighting
Zone 1 is where an explosive gas atmosphere is likely to appear occasionally during normal operation. Zone 2 is where it is not expected in normal running and, if it does appear, should only last a short time. Before you start, request certificate copies from whoever supplied the fittings. A specialist provider like MineGlow is used to that request, and having the documents in hand makes every later step quicker.
|
Feature |
Zone 1 |
Zone 2 |
|
Gas atmosphere |
Likely to occur occasionally in normal operation |
Not expected in normal operation, and brief if it does occur |
|
Minimum equipment protection level |
EPL Gb |
EPL Gc |
|
Common protection types |
Ex d, Ex e, Ex mb |
Ex ec (formerly Ex nA), plus anything suited to Zone 1 |
|
Audit focus |
Enclosure integrity, flameproof joints, glands, certification match |
Correct marking, general condition, correct selection |
Step-by-Step: How to Conduct the Audit
Here is the sequence I would follow on any site, whether it has 40 fittings or 4,000.
Step 1: Collect the Paper Trail
Pull the hazardous area classification drawings, equipment register, IECEx or ATEX certificates and previous inspection records. If the drawing is out of date, flag that first, because everything else depends on it.
Step 2: Walk the Site and Tag Every Luminaire
Give each fitting a unique ID and note its location, zone and mounting type. Photograph the nameplate. This register becomes your baseline for every future audit.
Step 3: Verify the Markings
Read each nameplate closely. Look for the Ex mark, certificate number, equipment protection level, gas group (IIA, IIB or IIC), temperature class, ambient range and IP rating. A missing or unreadable plate is a finding by itself.
With hazardous LED lighting, also confirm that the driver and any emergency battery pack are covered by the same certificate, since replacement parts often are not.
Step 4: Inspect Physical Condition
Look for cracked or hazed lenses, damaged gaskets, corrosion, loose fasteners, paint over joints, and signs of impact or water ingress. Reject non-original bolts and any drilled holes.
Step 5: Check Cable Entries and Earthing
Confirm glands are certified for the protection type, tightened properly and fitted with the correct seals. Unused entries need certified blanking plugs. Test earth continuity and look for loose or corroded bonding.
Step 6: Match Each Fitting to Its Zone
Compare each fitting's protection level, gas group and temperature class with the classification drawing. The temperature class must keep surface temperatures below the autoignition temperature of the gas present. A fitting rated only for Zone 2 must never be left in a Zone 1 location.
Step 7: Record, Rank and Close Out
Grade every defect as critical, major or minor. Isolate critical items, such as a Zone 2 fitting in Zone 1, until they are fixed. Then set the re-inspection date and update the register.
Common Findings That Fail an Audit
These turn up again and again on real sites:
• Missing or illegible nameplates
• Cracked lenses or perished seals
• Unused cable entries closed with ordinary plugs
• Uncertified replacement lamps, drivers or batteries
• Fittings installed in a higher-risk zone than their rating allows
• Loose, corroded or missing earthing
Conditions matter too. On hazardous lighting for oil and gas sites, salt spray, vibration and heat cycling are the usual culprits, so look hard at seals and fixings. Industrial hazardous lighting in dusty, wet or corrosive plants ages faster as well, which is a good reason to shorten your intervals there.
How Often Should You Audit?
Under IEC 60079-17, an installation needs an initial inspection, then periodic inspections or continuous supervision by skilled people. A common benchmark is a periodic inspection at least every three years, with sampling permitted. Harsh environments, past defects or modifications justify shorter intervals. Always check your site's own rules.
Frequently Asked Questions
1. What is the difference between IECEx and ATEX?
IECEx is an international certification scheme for equipment in explosive atmospheres. ATEX is the European legal framework. Many fittings carry both marks.
2. Who can carry out the audit?
A competent person with documented Ex training, such as competencies aligned to the IECEx Certification of Personnel Competence scheme. Experience with the specific protection types on site matters too.
3. Can I put any LED tube into an existing Ex fitting?
No. The certificate covers the luminaire as tested. Fitting an uncertified retrofit lamp can void that protection, so only use replacements approved for that exact fitting.
4. What does the temperature class on a fitting mean?
It shows the maximum surface temperature the equipment can reach, from T1 (450 degrees Celsius) down to T6 (85 degrees Celsius). That figure must stay below the autoignition temperature of the gas.
5. What happens if a fitting fails the audit?
Critical failures should be isolated straight away. Repair with certified parts or replace the fitting, document the work, and re-inspect before returning it to service.
6. Can a Zone 2 fitting be used in Zone 1?
No. Zone 1 requires equipment with protection level Gb or higher. A Zone 2 fitting (Gc) does not meet that requirement.
Final Thought:
A good audit is mostly patience: read the plates, look closely, write everything down. Do it that way and you will know exactly where each fitting stands before a regulator or insurer asks. If your results show ageing or mismatched fittings, MineGlow is a trusted name for certified hazardous area lighting solutions, and its team is worth a conversation about replacements and technical questions.
