HHSRS definition of hazards

A hazard is any risk of harm to the health or safety of an actual or potential occupier of accommodation that arises from a deficiency in the dwelling, building or land in the vicinity. Health includes mental health.[1]

A local authority has a duty to inspect properties for hazards and can take enforcement action against landlords under the Housing Health and Safety Rating System (HHSRS).

Find out more about local authority duties to assess hazards on Shelter Legal.

How hazards are defined

There are 21 potential hazards under the HHSRS.[2] Information about each hazard is listed in the HHSRS Operating Guidance.[3]

The guidance lists for each hazard:

• a description of the hazard

• the likelihood of harm for vulnerable groups

• health effects

• causes and behavioural factors

• preventative measures

Read the HHSRS guidance for more information on how hazards are defined on gov.uk.

Hazards in social housing

A social landlord has duties to resolve emergency and significant damp and mould hazards within fixed timeframes under Awaab's law.

Find out more about hazards in social housing on Shelter Legal.

The Housing Health and Safety Rating System (HHSRS) is a system for assessing housing conditions and hazards.

Under the HHSRS, a local authority:

• carries out inspections of rented housing

• identifies whether any specified hazards are present

• categorises those hazards according to objective criteria

How hazards are assessed

When completing an inspection under the HHSRS, a local authority should identify hazards and consider the likely impact on the health and safety of the occupier or visitor in residential accommodation.

Guidance says that:[4]

• any residential premises should provide a safe and healthy environment for any potential occupier or visitor

• the risk from hazards should be removed or kept as low as possible

• the property should provide protection from the external environment

The assessment should not consider the cost of remedying a hazard or how feasible it would be to fix. Societal expectations or tolerance for risk from certain hazards are also not relevant.

An HHSRS assessment should consider all parts of the building, including surrounding grounds.

The HHSRS covers hazards that are the responsibility of the owner or landlord to remedy. This includes hazards that are caused in whole or in part by the design, construction or maintenance of the property.

The HHSRS does not apply to hazards caused by the behaviour of the occupants or neighbours.

A hazard can include a risk from hygrothermal conditions which affect how heat and moisture travel through buildings. 

Damp and mould growth

A hazard can include threats to health from mould or fungal spores resulting from dampness or high humidity.[5] It can also include threats to health from house dust mites.

Damp and mould growth might cause threats to mental health and wellbeing.

Excess cold

A hazard can include threats to health from low indoor temperatures. Guidance states:[6]

• there is a small risk of adverse health effects for vulnerable groups below 19C

• serious health risks occur below 16C, including a much greater risk of respiratory and cardiovascular conditions

• there is a significant risk of hypothermia under 10C, especially for elderly people

Risk is highest in older buildings with solid walls, and lowest in newer, more energy efficient buildings.

Excess heat

A hazard can include threats to health from excessively high indoor temperatures.

High temperatures place increased stress on the cardiovascular and respiratory systems. This can lead to hyperthermia, heat exhaustion and heat stroke. Dehydration is a problem mostly for older people and the very young.

Guidance does not set a maximum temperature above which excess heat is considered to be a hazard.

A hazard can be caused by pollutants, including asbestos, carbon monoxide, lead and radiation.

Asbestos and manufactured mineral fibres

A hazard can be caused by the presence of and exposure to asbestos fibres and other manufactured mineral fibres (MMF).

Find out more about asbestos in housing on Shelter Legal.

Indoor air pollutants

A hazard can be caused by threats to health from exposure to:

• uncombusted fuel gas

• carbon monoxide

• nitrogen dioxide

• sulphur dioxide

• smoke

• volatile organic compounds

• biocides

Lead

A hazard can include threats to health from the ingestion of lead. For example, from lead based paints or pipework.

Radiation

A hazard can include threats from exposure to radon gas and its radioactive decay products.

Guidance states there is no clear evidence of health risks from low-level electromagnetic fields from mobile phone signals, Bluetooth and wifi.

Leakage from a microwave might be considered where it is provided by the landlord.

A hazard might be caused by an issue with space, security, light or noise.

Crowding and space

A hazard might be caused by overcrowding and a lack of space within the property for living, sleeping, and normal household life.

Entry by intruders

A hazard might be caused by difficulties in keeping a property secure against unauthorised entry. This includes harms from intruder entry and the fear of an intruder entering the property.

Lighting

A hazard might be caused by threats to physical and mental health associated with or inadequate natural or artificial light.

Noise

A hazard might be caused by threats to physical and mental health as the result of exposure to noise inside the property or its grounds.

A hazard might be caused by a problem with hygiene, sanitation and water supply.

Domestic hygiene, pests and refuse

A hazard can include:

• poor design, construction and layout so that the property cannot be easily kept clean

• access into and living places within the dwelling for pests

• inadequate and unhygienic provision for storing and disposal of household waste

• threats of infection from inadequate food preparation and storage facilities

• threats of infection from inadequate personal and clothes washing facilities

• threats of infection from inadequate sanitation or drainage

• mental health impacts from these issues

Water supply

A hazard can be caused by the quality and adequacy of the supply of water within the property for drinking, cooking and washing.

Water quality includes threats to health from contamination with bacteria, parasites, viruses and chemical pollutants.

A hazard can relate to risks of falls in the home.

Falls on level surfaces

A hazard can be caused by the risk of a fall on any level surface, such as a floor, yard or path.

It also includes falls associated with:

• a bath or shower

• trip steps, thresholds or ramps where the change in level is less than 300mm

Falls on stairs and steps

A hazard can be caused by the risk of a fall associated with stairs, steps and ramps where the change in level is more than 300mm.

This includes falls associated with:

• internal stairs and ramps

• external steps and ramps

• internal shared access routes

• fire escapes

It includes falls over balustrading on stairs or steps but not falls over balconies or from landings.

Falls between levels

A hazard can be caused by the risk of a fall from one level to another inside or outside the property. The difference must be more than 300mm.

For example, falls out of windows, from balconies or landings.

A hazard can be caused by electrical safety problems, threats from fire, burns or scalds.

Electrical hazards

A hazard can include hazards from shock and burns resulting from exposure to electricity including lightning strikes.

Fire and explosions

A hazard can include threats from exposure to uncontrolled fire and associated smoke in a dwelling.

This includes

• the threat from an explosion and flying debris

• the partial or total collapse of a structure as a result of a fire or explosion

• defects to the electricity supply, meters, fuses, wiring, sockets or switches

• injuries from clothing catching alight on exposure to an uncontrolled fire

The hazard does not include injuries caused by clothing catching alight from a controlled fire or flame.

Flames, hot surfaces and materials

A hazard can include threats of burns caused by contact with:

• a controlled hot flame, fire, hot objects or non-water based liquids

• scalds from contact with hot liquids and vapours

A hazard can be caused by the threat from a collision, ergonomic problems or structural collapse.

Collision, entrapment and ergonomics

A hazard can be caused by risk of physical injury from:

• trapping body parts in building features such as doors or windows

• collision with objects such as windows, doors, low ceilings, low door frames and walls

• physical strain associated with the use of the property

Physical strain from use of the dwelling can include door handles which are difficult to turn, or window catches which are hard to reach.

Structural collapse and falling elements

A hazard can be caused by the threat of collapse of the property.

This includes the whole or part of the dwelling collapsing, or of an element or part of the fabric being displaced or falling because of inadequate fixing, disrepair or as the result of adverse weather conditions.

Structural failure can occur internally or externally.