Dead and hazard trees in tree work: what the codes say

This page reports what the named codes, regulators and makers say. It is not training and does not teach the work. This page reports what the official source says. It is not legal advice: ask the office named here. It sets out what regulators in British Columbia, New South Wales, New Zealand, Great Britain and the United States say about assessing, climbing and felling trees that are dead, decayed or otherwise compromised. All pages were read on October 9, 2026. The courses that teach the work are in the guides on chainsaw tickets and certifications by country, and the UK award for windblown trees is described on its own page.

British Columbia

The WorkSafeBC Occupational Health and Safety Regulation has a short run of sections on tree climbing outside forestry operations, in force since December 1, 2021. Part 26 of the regulation says the employer must ensure a qualified arborist determines that each tree intended to be climbed can withstand the loads from the climbing and from the ground work around it. It then says a tree-climbing plan is prepared and passed to every worker involved.

Elsewhere in Part 26, section 26.11 on dangerous trees says that where it is known or reasonably foreseeable that work will expose a worker to a dangerous tree, the tree must be felled or a risk assessment must be made by a person who has completed a training program acceptable to the Board. The recommendations of that assessment are carried out before the work starts.

The regulation lists what the plan's preparer assesses for each tree: its structure, including shape, lean, root collar, roots, stems, trunk and branches, and the recurring patterns of failure for the species, such as rot, root damage or stem damage. It also lists what the plan names: the climbing system, the type and location of the first anchor point, each worker's duties and protective equipment, the means of communication and the rescue procedures. A hazard found after the plan is written is added to it and passed to the affected workers before work goes on.

The same Part says an anchor point is assessed as suitable for its loads before it is used, and that a cutting tool is run only when the climber is tied in with a climbing line or lanyard and a second means of securement. WorkSafeBC also publishes a safety bulletin on tree removal in residential and recreational settings, dated November 2023. It says arborists often face more risk when a tree is in poor health, dead or decaying.

One WorkSafeBC incident investigation summary from a September 2022 incident records a fatal injury when the rotten base of a tree snapped after the top was felled. Its listed causes include an inadequate assessment of the dangerous tree for climbing, safe work procedures that were not followed and no inspection of the high-risk work. The summary is set out in full on the guide to that case.

New South Wales, Australia

The SafeWork NSW code of practice Tree works says a competent person should inspect and assess the tree before work, covering overall condition and structural integrity, structural faults such as decay, hollows, growth habit and root plate failure, wind loading and ground conditions. It lists deadwood, decay, bark inclusions, cavities, termite or borer infestation, stump movement and root damage as defects that affect stability.

The code's assessment table says dead and decayed trees are unstable, that dead branches may not carry the combined weight of a worker and equipment, and that decay at the base or in a fork may let a tree split or collapse under that weight. For defects, the code sets out a hierarchy of controls. From the top it names removing the defect where possible, such as a hanging branch, and then avoiding climbing above the defect or loading the defective section. It lists as possible solutions felling or removing the section from below the defect, working from an elevating work platform, attaching the climber to a separate tree or stable part, and strengthening the defect by roping or bracing.

New Zealand

The WorkSafe New Zealand approved code of practice for safety and health in arboriculture says a proper inspection of the work area is made before any work or climbing to identify hazards such as decay or rot, dead branches and suspended material. It adds a visual hazard assessment of the tree including the rooted area before climbing. For felling it lists broken branches, deadwood or other overhead material that may dislodge, and decayed or weak spots, with extra hazards if they are in the hinge area. It says special care is taken when felling dead trees because parts may fall into the work area. It says that when branches are shortened before a tree is dropped, the arborist attempts to find out whether the tree can take the strain of lowering, and if not, other ways of removal are considered. The code notes on its page that it has not been updated to the 2015 health and safety Act and regulations and may still hold relevant practice.

Great Britain

The HSE lifting equipment in arboriculture page says the strength of lifting equipment needs careful consideration for rigging operations and for work in diseased or decayed trees, and that anchor points in trees form part of the lifting equipment. It says arborists using rope access or work positioning should be trained to select suitable anchor points, to recognise differences between tree species and to understand the effect of age, condition and disease. The HSE tree-climbing operations page says that when sectional felling, a minimum of two attachment or anchor points is used. HSE text on this page is adapted under the Open Government Licence v3.0.

United States

In the United States, OSHA's logging standard, 29 CFR 1910.266, defines a danger tree as a standing tree that presents a hazard because of conditions such as deterioration or physical damage to the root system, trunk, stem or limbs, and the direction and lean of the tree, and a snag as a standing dead tree or part of one. It says each danger tree is felled, removed or avoided, and that one left standing is marked with no work within two tree lengths unless the employer shows a shorter distance creates no hazard. It adds that each danger tree is checked for loose bark, broken branches and other damage before it is felled. That standard covers logging operations. OSHA's 2021 enforcement memo on tree care says that before any tree care operation employers need to check the health of the tree and assess the work site for fall and struck-by hazards. In its note on cranes it asks inspectors whether a tree is safe to climb, and says climbing decayed or damaged trees could be hazardous, giving insect damage or fire-stripped bark as examples. The tree care pages of OSHA, described in the guide on OSHA standards for tree work, show which general industry standards OSHA applies to tree care.

At a glance

Place	Source	What it says about a compromised tree
British Columbia	OHS Regulation, Part 26	A qualified arborist decides the tree can carry the loads, and a written climbing plan covers rot, root and stem damage
New South Wales	Tree works code of practice	Competent person assesses decay, deadwood and root plate failure, with a hierarchy of controls for defects
New Zealand	Approved code of practice, arboriculture	Inspection for decay, dead branches and suspended material before climbing, with special care when felling dead trees
Great Britain	HSE lifting equipment page	Anchor points in diseased or decayed trees need careful strength consideration
United States	OSHA 1910.266 and 2021 memo	Danger tree defined, felled, removed or avoided, with two tree lengths for one left standing; tree health checked before tree care

For how the defects themselves are described, see the guides on dead branches and hangers and tree risk assessment. The official case reports for tree work are listed in the case library.

To correct or remove an entry, write to the address at the foot of this page.