Poisonous plants and construction
Outdoor work can be hazardous - even with appropriate health and safety policies and risk assessments - if employees do not understand the risks and receive appropriate training to manage their own PPE responsibilities, then they may be putting themselves at increased risk.
The UK has its share of poisonous plants that may cause rashes, illness, and - in rare cases - death. When working in remote locations, or on building sites, make sure to assess the dangers on site, and remove (if possible) any plants that may cause harm to workers. The following plants are poisonous when ingested, but mostly skin irritants.
Plants that are skin irritants:
- Wolf’s Bane: Cases of accidental poisoning are rare, but the plant’s toxins can slow the heart rate, cause upset stomach, and can be fatal. Only handle with gloves.
- Stinging Nettles: A common sight in the UK, nettles have needle-like hairs which penetrate the skin and sting you. It’s accompanied by burning, itching, and rash. Use dock leaves to neutralise and cool the skin.
- Giant Hogweed: This plant grows up to five metres tall (16 feet) along footpaths and riverbanks, and the plant’s sap can cause severe painful burns if it comes into contact with the skin. It will make the skin sensitive to strong sunlight. Wash affected areas with soap and water. The blisters heal slowly and can cause phytophotodermatitis, which flares in sunlight. If you feel unwell after exposure, go to your doctor.
- Thorny Plants: Needles and spines from roses, holly, blackberry bushes, and brambles can cause infections on the skin. If you are stuck by a thorn, remove the thorns and soak the area in warm water. Wear protective gloves around these plants.
Wolf’s Bane: Photo credit: ![]() |
Stinging Nettles: Photo credit: ![]() |
Giant Hogweed: Photo credit: ![]() |
Thorny Plants:Photo credit: ![]() |
Plants that are poisonous when ingested:
These plants have leaves, berries, fruit, flowers, sap, or bulbs that can poison you if you eat them or give you a rash if you touch them.
- Poison hemlock
Photo credit: Dendroica cerulea via Visual Hunt / CC BY-NC-SA
- Foxgloves
Photo credit: dierken via VisualHunt / CC BY
- Lords and ladies
Photo credit: Johnson Cameraface via VisualHunt / CC BY-NC-SA
- Deadly nightshade
Photo credit: Plbmak via Visualhunt.com / CC BY-NC-ND
- Yew
Photo via VisualHunt.com
- Daffodil Bulbs
Photo credit: delayedneutron via VisualHunt.com / CC BY-NC-SA
- Chrysanthemums
Photo via Visualhunt.com
- Snowdrops
Photo credit: matthewvenn via Visual Hunt / CC BY-SA
- Mistletoe
Photo credit: bluefuton via Visualhunt / CC BY-NC-ND
Avoid touching these plants where possible, and do not eat them.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Ending decades of frustration, misinformation and distrust.
Essential tools in managing historically significant landscapes.
Classroom electrician courses a 'waste of money'
Say experts from the Electrical Contractors’ Association.
Wellbeing in Buildings TG 10/2025
BSRIA topic guide updates.
With brief background and WELL v2™.
From studies, to books to a new project, with founder Emma Walshaw.
Types of drawings for building design
Still one of the most popular articles the A-Z of drawings.
Who, or What Does the Building Safety Act Apply To?
From compliance to competence in brief.
The remarkable story of a Highland architect.
Commissioning Responsibilities Framework BG 88/2025
BSRIA guidance on establishing clear roles and responsibilities for commissioning tasks.
An architectural movement to love or hate.
Don’t take British stone for granted
It won’t survive on supplying the heritage sector alone.
The Constructing Excellence Value Toolkit
Driving value-based decision making in construction.
Meet CIOB event in Northern Ireland
Inspiring the next generation of construction talent.
Reasons for using MVHR systems
6 reasons for a whole-house approach to ventilation.
Comments
With reference to nettles and using dock leaves to alleviate the rash... try plantain leaves, they are way better!