Health and Safety – Giant Hogweed


Giant hogweed (Heracleum mantegazzianum) grows prolifically along many urban watercourses throughout London and is managed by a range of land owners. As well as being a particularly invasive species, contact with the sap of giant hogweed can result in severe burning and blistering of the skin after exposure to sunlight.

As the species needs to be treated, but contact can result in injury, there are certain health and safety aspects that need to be considered before, during and after treatment.

Giant Hogweed - dead seed heads. Copyright, K.Harper 2012

Giant Hogweed – dead seed heads. Copyright, K.Harper 2012


Limiting exposure to giant hogweed is the best way to minimise the danger it presents to human health. Before carrying out work on giant hogweed, ensure that you have the required personal protective equipment (PPE). Suggested equipment include:

  • Long sleeve trousers and long sleeve shirt (or body protection suit);
  • Eye protection; and
  • Long sleeve gloves.

After work, all equipment should be treated carefully to ensure that contact is not made with the protective clothes as this can be contaminated with plant material. Equipment needs to be washed down carefully and stored safely until next use.

First aid treatment of giant hogweed exposure includes washing the site of contact with clean water and limiting exposure to sun. It is important to seek medical advice.

Recommended Action

Individuals and organisations can limit the chance of exposure to giant hogweed by carrying out a few easy actions:

  1. Locate and map giant hogweed on your sites so that they can be treated at the same time to minimise exposure.
  2. Consider alternative management techniques which limit the physical contact required for removal. This can include using herbicides where appropriate. Ensure you have all appropriate PPE for use of chemicals and all required permits for its use.
  3. Ensure that you have all of the required personal protective equipment and the means to clean/store equipment before treatment.
  4. Ensure that you and others are aware of the appropriate first aid treatment for giant hogweed burns and that there is an appropriately trained first aid officer on site.