In brief
A plumber's risks arise not at a fixed workbench but on a site that changes every day: a loft, a manhole, the wall of an old building or a boiler room smelling of gas. This article covers the risks of confined spaces, hot work, gas leaks, pipe cutting and manual handling, together with an eight-question pre-start site check to apply before beginning work.
Why does plumber safety have to be rebuilt on every site?
In a factory, a machine stands in the same place every day; a plumber's workplace, however, changes every day. On Monday, the boiler room of an apartment block; on Tuesday, the service shaft of a construction site; on Wednesday, the ceiling void of a shop. Plumber safety is therefore managed not with a fixed list of risks but with a check completed each time according to the site.
Art. 4 of Law No. 6331 requires the employer to carry out a risk assessment and assign employees to suitable work. This obligation continues when a plumbing firm sends its employee to a customer's home or another employer's factory. When working at another employer's workplace, under Art. 23 the employers inform each other of the risks and work in coordination. In a private home, however, there is no employer with OHS obligations on the other side; assessing the site is left entirely to your team.
If the firm also installs or maintains heating, ventilation and air conditioning (HVAC), take note: in the List of Workplace Hazard Classes renewed in 2025, these activities are in the very hazardous class under codes 43.22.06 and 43.22.07. Firms working mainly in plumbing should check the class of their activity code in their SGK registration.
Before starting work: the pre-start site check
On arriving at the site and before starting work, the team leader should answer these eight questions. This check, which takes a few minutes, is the step that prevents most of the most serious accidents.
- Gas: Is there gas in or near the line to be worked on? Has the valve been closed, locked and tagged?
- Electricity: Is there a cable running through the wall to be cut or drilled? Is a metal pipe being used as an earthing or equipotential bonding connection?
- Confined space: Will anyone enter a loft, shaft, manhole or duct? Are a pre-entry measurement and an attendant needed?
- Hot work: Will welding, soldering or a blowtorch be used? Is there combustible material nearby?
- Building materials: In an old building, is pipe insulation or wall cladding suspected of containing asbestos?
- Carrying: By which route and with how many people will heavy items such as radiators, combi boilers and bundles of pipe be carried?
- Height: Will the work be done from a ladder or a platform?
- Communication: Is the team working alone; whom will they notify, and how, in an emergency?
Turning this list into a one-page form filled in on site and keeping it with the work order is both a reminder for the team and a record that can be shown during inspections. If the pipe is metal and is used as an earthing connection, a temporary bonding bridge is installed together with an electrician before cutting; otherwise a voltage difference may arise between the two ends of the pipe at the moment of cutting.
Natural gas installation safety: leaks, testing and commissioning
Natural gas installation safety revolves around two hazards: ignition of leaking gas and the build-up of combustion products, especially carbon monoxide, in an enclosed space.
- Leaks: Natural gas is lighter than air and rises towards the ceiling; LPG is heavier than air and collects at low points such as basements, pits and ducts. Where gas is smelled, no light switch, doorbell, telephone or device that may produce a spark is used; the area is ventilated, the main valve is closed and the area is evacuated. The natural gas emergency line is 187.
- Pressure testing: In the tightness test of a new installation, the test pressure and duration are applied according to the relevant specification. During the test, nobody stands in front of fittings; test equipment and pressure gauges are selected for the appropriate pressure range.
- Working on a live gas line: No connection is undone until the gas has been shut off. After the valve has been closed, the gas remaining in the line is safely released, and lockout and tagout prevent the valve from being opened by someone else.
- Carbon monoxide: When commissioning a combi boiler or boiler, or when fault-finding, the flue connection, combustion air and combustion are checked. A team working in an enclosed boiler room using a portable CO detector gets a warning before symptoms begin. For symptoms and first response, see our article on carbon monoxide poisoning from heaters.
For internal natural gas installations, design approval, testing and turning on the gas depend on the distribution company's technical specification and procedures. This article focuses only on worker safety.
Plumber welding and hot work
Soldering copper pipe, welding steel pipe and heating with a blowtorch are a plumber's daily work. In plumbers' welding work, the fire risk often comes not from the flame itself but from insulation behind the wall, a timber joist or dust in the loft. Insulation smouldering inside can turn into a fire after the team has left the site.
Rules of practice:
- Before hot work begins, combustible material in the immediate vicinity is removed or protected with a fire-resistant blanket; a suitable extinguisher is kept to hand.
- After the work is finished, the area is watched for a while; behind walls and ceilings is checked by touch and sight.
- Small gas cylinders used for blowtorches are carried upright and secured in the vehicle and are not left in a closed vehicle cab.
- For welding in enclosed spaces, ventilation is provided against fumes; suitable respiratory protection is used if necessary.
Hot work carried out at another employer's facility usually proceeds under a written permit. We described the contents of the permit form in our article on the hot work permit, and the general risks of welding work in our article on welders' occupational safety risks.
Confined spaces and work inside ducts and sewers
Plumbers frequently enter narrow and enclosed spaces: service shafts, lofts, underfloor voids, manholes and ducts. Work inside ducts has two separate hazards: gas or oxygen deficiency in the air, and collapse or flooding.
- Atmosphere: Hydrogen sulphide (H₂S) can build up in manholes and ducts connected to the sewer. In Annex 1 of the Regulation on Health and Safety Measures for Work with Chemical Substances, the limit value for H₂S is 5 ppm as an 8-hour average and 10 ppm for 15-minute short-term exposure. Nobody enters until oxygen, flammable gas and H₂S have been measured before entry. We described how to take measurements in our article on confined space gas measurement.
- Attendant: While someone is working inside, an attendant stays outside and keeps in constant contact with them. The attendant does not go in to rescue; they apply the rescue method planned in advance.
- Excavation: In trenches dug for connections outside the building, battering or shoring is provided according to depth and ground conditions; materials are not piled at the edge of the excavation. Details are in our article on excavation and trench collapse measures.
For the full confined space entry procedure, see our guide on working in confined spaces.
Pipe cutting, threading and manual handling
The angle grinder used for cutting pipes carries risks of disc bursting and kickback. On a pipe threading machine, the rotating pipe can catch loose clothing or a glove and wind up the arm. Therefore:
- When grinding, the disc is selected to match the machine's speed, the guard is not removed, and eye and face protection are used.
- Loose clothing and wristbands are not worn when working near a rotating pipe; the foot pedal is kept within easy reach, and it is checked that the machine stops when the pedal is released.
- Burrs on cut pipe are removed immediately; a burr causes deep cuts when the pipe is later handled.
- In old buildings, pipe insulation or sheets suspected of containing asbestos are not cut or broken; an assessment is made first. For details, see our article on suspected asbestos materials in old buildings.
Radiators, combi boilers, water tanks and bundles of pipe are often carried up narrow stairs. Art. 5 of the Regulation on Manual Handling requires loads to be moved primarily by mechanical means. Stair trolleys, carrying straps and two-person carrying should be the default method for heavy items.
Risks and records in one table
| Job | Main risk | Basic measure | Related record |
|---|---|---|---|
| Working on a gas line | Ignition, explosion | Closing the valve, lockout and tagout, ventilation | Pre-start site check form |
| Commissioning combi boilers and boilers | Carbon monoxide | Flue and combustion check, CO detector | Commissioning record |
| Welding, soldering, blowtorch | Fire, fumes | Removing combustibles, extinguisher, post-work watch | Hot work permit (at another workplace) |
| Manholes, ducts, shafts | Toxic gas, oxygen deficiency | Pre-entry measurement, attendant, rescue plan | Confined space entry permit |
| Pipe cutting, threading | Cuts, entanglement | Guard, suitable clothing, pedal check | Machine instructions |
| Carrying radiators and combi boilers | Back injury, falls | Mechanical aids, two people | Risk assessment |
Annex 1 of the vocational training regulation contains four lines that may concern plumbers: 22 (all kinds of welding work), 31 (construction work, including sewers and repairs), 81 (transport of gas, water and similar substances by pipeline and maintenance and repair of these lines) and 91 (sewer and septic tank work). If the workplace is in the hazardous or very hazardous class and the employee actually does this work, a vocational training certificate is required before hiring. We described the valid certificates in our article on the list of occupations requiring vocational training.
When providing OHS specialist services to plumbing and heating firms in Bursa and the surrounding provinces, we adapt the pre-start site check form to the firm's work order system and give team leaders hands-on training on site. Our construction sector page also provides guidance for plumbing teams working on construction sites.
Frequently Asked Questions
What should a plumber do when gas is smelled?
Ventilate the area without using light switches, telephones or devices that may produce sparks, close the main valve and evacuate the area. Work does not resume until the source of the leak has been eliminated and the area has been found safe by measurement. If necessary, the 187 natural gas emergency line is called.
Who carries out the risk assessment when working in a customer's home?
The employer of the plumbing firm. The homeowner is not an employer with OHS obligations. The firm prepares a general risk assessment covering commonly encountered sites and completes it with a pre-start site check before each job.
Do plumbers need a vocational training certificate?
Yes, if the workplace is in the hazardous or very hazardous class and the employee does welding, construction, pipeline or sewer work listed in Annex 1 of the vocational training regulation. The certificate is required before hiring, and a copy is kept in the personnel file.
What measurements are taken before entering a duct?
At a minimum, oxygen, flammable gas and hydrogen sulphide are measured. The measurement is made immediately before entry and continued throughout the work. If the values are not acceptable, nobody enters until ventilation has been provided or suitable respiratory equipment is available.
A certified specialist matched to your hazard class: site inspections, approved logbook, training plan, annual plan and report follow-up.
Bursa SİSTEMER OSGB Technical Team — written from the field experience of our OHS specialists and workplace physicians. Legal information is valid as of the publication/update date; contact us for an assessment specific to your business.