Management of the risk from falling trees or branches

SIM 01/2007/05


This document provides guidance for HSE Inspectors and LA Enforcement Officers on

  • the standards for managing the risk from trees, including risk assessment and where appropriate, routine checks by a competent person. Duty holders should have such systems in place to control risks from trees to their employees, contractors and members of the public.
  • handling these issues and approaching enforcement decisions in accordance with the principles and expectations of the HSE Enforcement Policy Statement (EPS)

It is not intended as a guide to duty holders.


This guidance is aimed specifically at duties under Section 3 Health and Safety at Work etc Act 1974 (HSW Act) and should be read in conjunction with HSE's Section 3 guidance , Investigation operational procedure, EPS and Work- related death protocol (WRDP).

See also situational example 18 in the document Guidance for FOD in responding to (non-construction) public safety incidents where Section 3 of HSWA applies.

A good deal of relevant guidance has been produced by various organisations, including the National Tree Safety Group, the Arboricultural Association and the Forestry Commission. Their guidance provides advice to help duty holders comply with the Occupiers Liability Acts and other legislation and it may also be helpful to investigating inspectors. However, it should be noted that it represents 'best practice' guidance for managing trees, not the minimum standard required by Section 3 HSW Act as outlined above.


If Inspectors are called upon to examine standards of tree management following an incident, or if they identify a matter of evident concern during a visit, they should base their approach to deciding whether to investigate on HSE's general guidance on Section 3 HSW Act, HSE's operational guidance on Section 3 enforcement and the additional advice and guidance in this document. Any enforcement action should be taken in accordance with the HSE EPS.

Proactive inspection of duty holders' systems for tree management is not envisaged.


What is the risk?

Each year between 5 and 6 people in the UK are killed when trees or branches fall on them. Around 3 people are killed each year by trees in public spaces. Thus the risk of being struck and killed by a tree or branch falling is extremely low (in the order of one in 10 million for those trees in or adjacent to areas of high public use). However the low level of overall risk may not be perceived in this way by the public, particularly following an incident.

The average risk is firmly in the "broadly acceptable" region of the tolerability of risk triangle published in HSE's "Reducing Risks Protecting People". However, "Reducing Risks, Protecting People" explicitly states that "broadly acceptable" is a general guide and not a definitive statement of what is reasonably practicable in law.

What is required?

Employers and persons carrying out undertakings or in control of premises all have duties under the HSW Act. In particular, there is the duty to do all that is reasonably practicable to ensure that people are not exposed to risk to their health and safety.

Doing all that is reasonably practicable does not mean that all trees have to be individually examined on a regular basis. A decision has to be taken on what is reasonable in the circumstances and this will include consideration of the risks to which people may be exposed.

Around half of all fatalities due to falling trees or branches occur in public spaces, such as a park or beside roads, so Section 3 HSW Act may be applicable. Whilst HSE may regard the average risk as extremely low, the law requires that where reasonably practicable measures are available, in individual cases, they should be taken. Whilst the risk of such incidents puts them outside HSE's and LAs main proactive priorities, inspectors may be called upon to investigate serious incidents, including fatalities.

Other legislation

In addition to duties under the HSWA there are a number of reasons why LAs (as duty holders) and others may want to manage their tree stocks, for example responsibilities under other legislation and the risk of civil liabilities to:

  • reduce the risk of property damage from subsidence;
  • maintain stocks to preserve their amenity, conservation, and environmental value;
  • prevent personal injury through trips and falls on footways disturbed by tree roots; and
  • prevent vehicle damage and personal injury from obscured sightlines on the highway.

For these and other reasons, some duty holders may undertake inspection of trees
beyond the reasonably practicable requirements of the HSW Act.

Other legislation relevant to the management of trees includes, for example the Occupiers' Liability Acts 1957 and 1984, Occupiers Liability Act (Scotland)1960, Land Reform (Scotland) 2003, the Countryside and Rights of Way Act 2000 (CRoW), the Wildlife and Countryside Act 1981, the Marine and Coastal Access Act 2009, as well as legislation relating to Sites of Special Scientific Interest, planning issues and Tree Preservation Orders.

Suggested approach to tree management

Details of a suggested simple tree management system are given in Appendix 1.

Enforcement guidance

Enforcement may be appropriate following an incident or investigation of a complaint and should be in accordance with HSE's EPS and with HSE's Enforcement Management Model (EMM). In particular, consideration should be given as to how far the duty holder fell below what could reasonably be expected in the circumstances. This should be informed by the broad approach outlined above and factors such as:

  • the frequency of public access to the tree;
  • the existence of a system for managing trees based on the level of risk;
  • the implementation of the system in practice, including a procedure to act on issues of concern, for example, reports of structural faults;
  • the need to comply with other legislation eg the Wildlife and Countryside Act, Tree Preservation Orders etc. Such legislation generally allows that trees in a dangerous condition may be felled. However, a specific check should be made before considering enforcement action.

Consideration should also be given to the risks to persons that arise from the failings of the duty holder, along with the factors set down in paragraph 39 of the EPS. Of particular relevance will be any history of previous incidents in the area managed by the duty holder and any previous advice or enforcement in relation to the duty holder.

For the purposes of the EMM, this operational guidance should be considered 'established' guidance. The benchmark, based on duties under HSW Act is a 'remote' risk of 'serious personal injury.

Inspectors should seek advice from the Agriculture and Waste and Recycling Sector, the Entertainment, Leisure and Consumer Services Sector or the Central and Local Government, Education and Research Sector, as appropriate, before issuing an improvement notice or considering prosecution.

Further References

National Tree Safety Group, comprising key industry stakeholders, has produced guidance on trees and public safety.

The Health and Safety Executive was consulted in the production of these publications and endorses the sensible, proportionate, reasonable and balanced advice to owners on managing the risk from trees set out in the guidance.


OPSTD, Agriculture and Waste Recycling Sector – Agricultural Safety Section, HSE Nottingham.

Appendix 1

Given the large number of trees in public spaces across the country, control measures that involve inspecting and recording every tree would be disproportionate to the risk. Individual tree inspection is only likely to be necessary in specific circumstances, for example, where a particular tree:

  • is in a place frequently visited by the public;
  • has been identified, for example, as having structural faults that are likely to make it unstable; and
  • a decision has been made to retain it with these faults.

Public safety aspects can be addressed by tree owners as part of their approach to managing tree health. A sensible approach will ensure the maintenance of a healthy tree stock, the sound management of the environment and will usually satisfy health and safety requirements.

An effective system for managing trees should meet the requirements set out in the Management of Health and Safety at Work Regulations 1999 and the associated ACOP (guidance is contained in HSG 65 Successful health and safety management and INDG 163 Five steps to risk assessment). Such a system is likely to address the following:

  • An overall assessment of risks from trees - identifying groups of trees by their position and degree of public access. This will enable the risks associated with tree stocks to be prioritised, and help identify any checks or inspections needed.
  • There are several approaches to managing the risks from trees that involve 'zoning' trees according to the risk of them falling and causing serious injury or death. As a minimum, trees should be divided into two zones:

Zone one where there is frequent public access to trees (eg parks/ recreation grounds, in and around picnic areas, schools, children's playgrounds, popular foot paths, car parks, or at the side of busy roads). As a rough guide trees in Zone 1 are those that are closely approached by many people every day.

Zone two where trees are not subject to frequent public access.

  • In most case individual records for trees are unlikely to be necessary if zones and the trees in the zones are clearly defined - maps may be useful here.
  • For trees in a frequently visited zone, a system for periodic, proactive checks is appropriate. This should involve a quick visual check for obvious signs that a tree is likely to be unstable and be carried out by a person with a working knowledge of trees and their defects, but who need not be an arboriculture specialist. Informing staff who work in parks or highways as to what to look for would normally be enough.
  • Any system that is put in place for managing tree safety should be properly applied and monitored, including:
    • A short record of when an area or zone or occasionally an individual tree has been checked or inspected with details of any defects found and action taken.
    • A system for obtaining specialist assistance / remedial action when a check reveals defects out with the experience and knowledge of the person carrying out the check.
    • A system to enable people to report damage to trees, such as vehicle collisions, and to trigger checks following potentially damaging activities such as work by the utilities in the vicinity of trees or severe gales.
    • Procedures for ensuring the safety of the public during high winds, for example, where practicable by closing or restricting access to parks and gardens or footpaths.
    • Monitoring to ensure that the arrangements are implemented in practice.
  • Occasionally a duty holder may have responsibility for trees that have, for example, serious structural faults but which they decide to retain. Where such a condition is suspected and the tree also poses a potentially serious risk because, for example, its proximity to an area of high public use, a specific assessment for that tree and specific management measures, are likely to be appropriate.
  • Once a tree has been identified by a check to present an elevated risk, action should be planned and taken to manage the risk. Any arboriculture work required should be carried out by a competent arboriculturist as such work tends to present a relatively high risk to the workers involved.
  • Inspection of individual trees will only be necessary where, for example, a tree is in, or adjacent to, an area of high public use, has structural faults that are likely to make it unstable and a decision has been made to retain the tree with these faults.

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Updated 2023-01-20