Generator Safety: Exhaust, Fuel and Inspection

Why is generator safety a separate topic?

In most workplaces, the generator either waits quietly in a basement room or runs on a construction site, on the back of a loaded truck or in front of the warehouse door on the day of a power cut. The first is forgotten because it only comes on a few times a year; the second is left without rules because it changes location every day. Yet generator safety requires managing four different risks on the same machine: exhaust gas, fuel and fire, electricity and noise.

In Bursa and the surrounding provinces, production facilities in OIZs (organised industrial zones), hospitals, hotels and large residential complexes rely on standby generators, while construction sites, repair crews and trade fair and event work rely on portable generators. The headings below cover both.

Exhaust gas and generator carbon monoxide risk

A diesel or petrol engine produces carbon monoxide when fuel does not burn completely. This gas is colourless and odourless; poisoning, which starts with headache, dizziness and nausea, can progress to loss of consciousness. Most generator carbon monoxide accidents happen through the same mistake: running it "just for a short while" in an enclosed space.

• A portable generator runs outdoors. A basement, closed warehouse, container, tent or garage is not a suitable place, even with the door open.
• The exhaust direction is checked. The exhaust should point away from doors, windows and ventilation inlets; gas drawn back inside can build up in the building.
• In the generator room, exhaust line connections should be gas-tight, the room's ventilation openings should not be blocked and the room should not be used as a store.
• A CO detector is placed in the generator room and in enclosed spaces close to where the generator runs; the alarm setting and test method follow the manufacturer's instructions.

There is no limit value for carbon monoxide in the Annex 1 table of the Regulation on Chemical Agents; this does not mean there is no risk. For symptoms and first response, see our article on heaters and carbon monoxide poisoning. Running a pump or generator indoors to pump water out of a basement during a flood is also a known trap; our article on floods and water ingress offers guidance for this scenario.

Generator refuelling and fuel storage

A significant proportion of fires start during refuelling: fuel spilled onto a hot exhaust manifold or silencer ignites. The rule for generator refuelling is simple:

1. Stop the generator and wait for hot surfaces to cool.
2. Refuel in a well-ventilated place away from sparks and open flames; no smoking.
3. Use a suitable, lidded and labelled fuel container and a funnel; place a drip tray under the generator.
4. Do not fill the tank to the brim; do not start the generator without wiping up spilled fuel.
5. Keep a fire extinguisher of a suitable type at the refuelling point.

Fire safety for fixed generators is governed by the Regulation on the Protection of Buildings from Fire (BYKHY). Under Art. 66 of the regulation, the walls, floor and ceiling of the generator room are built to be fire-resistant for at least 120 minutes; if the room is inside the building, smoke and heat from a fire must not spread to escape routes; and clean water, waste water, flammable liquid and gas installations may not pass through the generator room. Art. 56 applies to the generator's main fuel tank: the tank is placed in an adequately ventilated space protected by fire-resistant partitions, a bund holding at least one third of the tank capacity is provided, and metal parts are earthed against static electricity. For where and how much fuel can be kept in jerrycans, see our article on storing flammable liquids.

Generator earthing and electrical safety

A generator is an electrical source in its own right; the protection system on the grid does not protect it. Generator earthing and output protection must therefore be planned at installation.

• Frame earthing: The frame of a portable generator is earthed in accordance with the manufacturer's instructions. Annex 4 of the Regulation on Occupational Health and Safety in Construction Work requires frame safety earthing of electrically powered work equipment on site and the use of suitable residual current devices in main and sub-panels.
• Residual current protection: Hand tools and extension leads connected directly to the generator are supplied through a distribution panel with a residual current device.
• Backfeed: Connecting the generator to the building installation through a socket or panel without a suitable transfer arrangement feeds voltage back into the grid. This can electrocute electricians working on the line and burn out the generator when the grid comes back. The connection is made only by an authorised electrician, through a transfer panel.
• Cables and wet ground: Cables are not run unprotected across vehicle routes, joints are not exposed to water, and the generator is not run unprotected in the rain.

One more feature of standby generators surprises maintenance teams: when the grid fails, the generator starts by itself and the transfer panel takes over the load automatically. So if work is to be done on the panel or on the generator itself, isolating only the grid side is not enough; automatic start is disabled, the battery is disconnected and the control is locked and tagged. Likewise, no one works on the exhaust, belt or fan area while the generator is running. For isolation and locking steps, see our article on lockout and tagout (LOTO).

For the logic of earthing measurement, see our article on earthing and residual current devices, and for site panels, our article on temporary electrical installations on construction sites.

Generator periodic inspection: what happens in the annual inspection?

Annex III of the Regulation on Health and Safety Conditions in the Use of Work Equipment lists the generator among installations in Table 3, which was renewed on 23 December 2025.

The regulation also requires that, when portable equipment not subject to installation and assembly conditions is used off-site, the latest periodic inspection report is kept with the equipment. Ask the firm bringing a hired generator to the site for this report. A generator that has not been used for a long time or has been affected by an event such as a flood or earthquake should also be inspected before being put back into service.

You can find what "defective" or "not compliant" notes in the report mean in our article on how to read a periodic inspection report, and the intervals for other equipment in our article on periodic inspection intervals for work equipment. The 2026 basic administrative fine for failing to have the required inspections carried out is 33,326 TL; for the calculation, see the OHS administrative fines tool.

Operator's routine checks and noise

The annual inspection does not replace day-to-day attention. Give the person running the generator a short checklist based on the manufacturer's instructions:

• Fuel, oil and coolant levels; whether there are signs of leaks underneath.
• Soundness of the exhaust connections and silencer.
• Battery connections and oxidation on the terminals.
• Condition of cables, sockets and the earth connection.
• Whether the emergency stop button works and is unobstructed.
• For standby generators, a record of test runs carried out at the interval recommended by the manufacturer.

Generators are a source of high noise. Under the noise regulation, hearing protection is made available at the lower action value of 80 dB(A), its use is mandatory at the upper action value of 85 dB(A), and the 87 dB(A) limit value may not be exceeded under any circumstances, taking account of the protector's effect. If people work next to the generator for long periods, we plan exposure measurement with an authorised laboratory. The silencer and exhaust line also carry a serious burn risk; put a barrier around them.

Under our periodic inspection service, we compile your equipment inventory, plan annual inspections with authorised persons and follow up defects in the reports. You can track inspection dates with the OHS calendar.

Frequently Asked Questions

How often is a generator periodically inspected?

Under Annex III of the Regulation on Work Equipment, at least once a year if no interval is specified in the standards. The inspection is carried out according to the TS ISO 8528 series by an authorised electrical engineer, technical teacher, technician or senior technician registered in EKİPNET.

Can a portable generator be run indoors?

No. Even with the door open, carbon monoxide from the exhaust can build up in enclosed and semi-enclosed spaces. A portable generator is run outdoors, with its exhaust pointing away from doors and windows.

Can fuel be added to a generator while it is running?

It should not be. Fuel spilled on the hot exhaust and silencer can ignite. The generator is stopped, allowed to cool and refuelled using a drip tray.

Who is responsible for inspecting a hired generator?

The employer who has the equipment used in the workplace is also responsible for ensuring it has been inspected. Ask the hire firm for the latest periodic inspection report and make sure it is kept with the equipment.