Dangers of Giant Hogweed

Giant Hogweed (Heracleum mantegazzianum) contains toxic sap that can cause severe burns.

At 20ft tall with dinner table sized leaves Giant Hogweed is an impressive plant that was once planted in gardens.  However, it is highly invasive and has spread throughout the whole of Great Britain, primarily favouring river banks but also other areas such as parks, cemeteries and wasteland.

The sap of Giant Hogweed contains toxic chemicals known as furanocoumarins.  When these come into contact with the skin, and in the presence of sunlight, they cause a condition called phyto-photodermatitis: a reddening of the skin, often followed by severe burns and blistering.  The burns can last for several months and even once they have died down the skin can remain sensitive to light for many years.

Every year there are press articles about gardeners, contractors, ramblers, children and others that have been hurt by this plant, just like this Sun newspaper article: Burned nurse in toxic sap warning (PDF)
Giant hogweed growing on a verge, and burns on an arm caused by the plant
Burns caused by giant hogweed on a leg

Thin strip of image show tree trunk and bark