'Safe' and 'unsafe' are defined terms and are not opposites. They are better understood as defined points on a spectrum of risk of harm or damage to property. Safe is defined as no significant risk of harm or damage while unsafe is defined as a significant risk of serious harm or significant damage.

This means that there is a spectrum of safety from safe through to unsafe. At one end, installations or equipment that meet a standard or code specified in regulation are considered to be safe, while at the other end, an installation that meets any of the unsafe criteria set out in the regulations is deemed to be unsafe.

Something that is non-compliant is somewhere in the middle of the spectrum and may not necessarily be unsafe. The regulations state that an installation that is non-compliant with the current requirements may continue to be used provided it was compliant when first installed and is not now unsafe.

The full definition of safe and unsafe is found in Regulation 5(external link) of the Electricity Regulations and Regulation 4(external link) of the Gas Regulations.

The Regulations also cite specific situations which are deemed to be unsafe.

Electricity

Regulation 20(external link) of the Electricity Regulations defines electrically unsafe works and installations. Works and installations are unsafe if:

• the characteristics of any fittings are impaired
• the conductors are inadequately identified (e.g. the neutral conductor must be black / black must not be used for any other conductor)
• the connections are not secure and reliable
• cooling conditions are impaired
• there is a risk of ignition (e.g. fittings subject to high temperature unguarded)
• cables are not protected against the risk of damage or are bent beyond their design criteria
• there is insufficient space to work on the installations safely.

The Regulations also define:

• Unsafe low voltage fittings – Regulation 22(external link)
• Unsafe appliances – Regulation 23(external link)
• Unsafe RCDs – Regulation 24(external link).

Gas

Regulation 11(external link) of the Gas Regulations define unsafe distribution systems or gas installations. Networks and installations are unsafe if:

• Measures are not in place to ensure:
• a release of gas is detectable or ignition of release is prevented
• gas is not released in an uncontrolled manner and ensure that any oxygen and gas is prevented from mixing in a pipe
• persons are not exposed to harmful products of combustion of gas
• persons and property are not exposed to excessive forces
• the failure of any control or safety device does not expose the downstream equipment to excessive pressure above the rated pressure of any distribution system and equipment downstream of that control or safety device
• the effective isolation and shut-off of the gas supply, including during an emergency.
• the safety-related characteristics of any fittings are impaired
• pipes and pipe joints are inadequate and unreliable
• the fittings have a gas leak or are capable of being operated in a hazardous way
• the fittings are exposed to a pressure exceeding their maximum rated pressure
• a pipe is inadequately protected against the risk of damage or corrosion; or subject to forces beyond its design criteria; or there is insufficient space, access, lighting, ventilation, or facilities to operate, maintain, test, and inspect any fittings required to be operated, maintained, tested, or inspected; or
• fittings subject to high temperatures can create a risk of ignition of flammable materials or a risk of injury to persons or damage to property. 

The Regulations also define:

• Additional rules for gas installations - Regulation 12(external link)
• Additional rules for gas appliances - Regulation 13(external link)
• Additional rules for the supply of gas - Regulation 14(external link)