The Gas Industry Unsafe Situations Procedure (GIUSP) tells Gas Safe registered engineers how to deal with unsafe gas installations, and it uses two categories, Immediately Dangerous and At Risk, that determine whether an appliance must be disconnected and who is responsible for it being repaired.

What GIUSP is

According to Gas Safe Register’s April 2024 factsheet, the Gas Industry Unsafe Situations Procedure is guidance available to all gas engineers, designed to protect householders from unsafe gas appliances, chimneys, flues and pipework. It assists engineers in complying with gas safety law, including the Gas Safety (Installation and Use) Regulations 1998, and applies to installations fuelled by different types of gas, in homes and businesses. The legislation marks the 1998 Regulations as extending to England, Wales and Scotland, so this guide describes Great Britain; Northern Ireland has separate gas safety regulations that are not covered here.

The factsheet says that when an engineer identifies an unsafe situation they should explain what the fault is and try to find the cause and repair it. Where that is not possible, they should tell the householder that the fault must be repaired before the installation is used again. If it cannot be corrected immediately, the engineer should make the installation safe, after first seeking the householder’s permission, which is normally done by disconnecting it or turning off the gas to the affected part, depending on how serious the defects are.

Immediately Dangerous

The factsheet defines an immediately dangerous installation as one that, if operated or left connected to the gas supply, is considered an immediate danger to life or property. It will be disconnected, with the householder’s permission, and must not be used until the defects are repaired. For natural gas, if the householder refuses permission to disconnect an installation or individual appliance, the engineer will report the situation to the Gas Emergency Service Provider, which has legal powers to demand entry to make the situation safe or to disconnect the gas supply. The factsheet adds that the provider does not have the same powers with LPG installations.

At Risk

An at risk installation is one where one or more recognised faults are present that could constitute a danger to life or property without further faults developing. With permission, the installation will be turned off and should not be used again until repaired. In a limited number of cases turning off the gas supply will not remove or reduce the risk; then the householder receives a warning notice and is told whom to contact for further investigation.

Not to current standards

Separately, an engineer may say an installation is not in accordance with current standards. The factsheet points out that older installations may not meet today’s requirements without being unsafe, and that bringing one up to current standards is always a good idea but often depends on whether the work can be done at reasonable cost or whether other work, such as a replacement appliance, is planned. It describes only two GIUSP defect categories, so an entry in this category is advice rather than a classification requiring disconnection.

Warning labels and who is responsible

If the Gas Emergency Service Provider attends after a smell of gas or fumes and cannot confirm that the installation is safe, it may attach a “Danger Do Not Use” label and issue a warning notice. The factsheet says that, once a warning notice has been issued, the installation must not be used until checked by a suitably qualified Gas Safe registered engineer, and that it is the householder’s or landlord’s responsibility to arrange the check. The same applies after an engineer identifies an unsafe situation: it is the occupier’s, landlord’s or agent’s responsibility to make sure the installation is not used until it is repaired, and the engineer should tell the landlord or agent where appropriate.

Wider safety advice from HSE

The Health and Safety Executive says it is illegal for anyone to use a gas appliance they suspect is unsafe: turn it off and do not touch it until a Gas Safe registered engineer has checked it. If a gas leak is suspected, call the National Gas Emergency Service on 0800 111 999, open all doors and windows and shut off the gas at the meter control valve if known. HSE also strongly advises that gas appliances, flues and pipework are installed, maintained and serviced at least annually by a Gas Safe registered engineer.

FAQs

Can an engineer disconnect my boiler without my permission?

The Gas Safe factsheet says disconnection is done with the householder’s permission. For natural gas, refusal is reported to the Gas Emergency Service Provider, which has legal powers to enter and make the situation safe.

Does “not to current standards” mean my boiler is unsafe?

No. The factsheet says an older installation may fail current standards without being unsafe, and updating it depends on cost and other planned work.

Who arranges the repair after a Danger Do Not Use label?

The householder or their landlord, according to the factsheet, using a qualified Gas Safe registered engineer.

Bottom line

GIUSP gives engineers a clear framework: an Immediately Dangerous appliance is disconnected, an At Risk appliance is turned off and must be repaired, and neither should be used again until fixed. The responsibility to arrange the repair rests with the householder or landlord. This is general information about Great Britain, not advice on a specific installation.

Sources

This guide draws on the following primary sources, current as of 20 September 2026:

• Gas Safe Register, “Gas Industry Unsafe Situations Procedure Explained” (PDF, issued 22 April 2024)
• Health and Safety Executive, “Gas safety – Home owners”
• legislation.gov.uk, “The Gas Safety (Installation and Use) Regulations 1998, regulation 30: Installation of gas appliances”

Related guides

Best Boiler Deals is an independent guide. We may earn a fee from some links; this never affects what we write. This article is general information, not regulated advice on any specific installation — always confirm the details with a Gas Safe registered engineer.