This plant is one of the 10 plants in North America (not including fungi) that kids need to know to steer clear of. However, this was left for us to learn and teach our children in order not to be endangered as a result of their curiosity.
Namely, if you accidentally break a stem or touch any of the sap, which is easy to accidentally do due to the stalk’s height, you will begin to develop grotesque blisters! Characteristics to watch out for include green stems with purple patches that are a bit hairy with white hairs.
Ask a Prepper explains the consequences of a contact with this plant:
"If you come into contact with the plant’s sap you can expect sever blistering, possible blindness f it comes into contact with your eyes and possible third degree burns. These effects come from the type of chemicals that it contains. When these chemicals come in contact with human skin they dramatically increase the skins sensitivity to light.
This can cause blisters that are actually very painful and form within around 48 hours and can last from anywhere between a few months to six years. It can cause LONG TERM sensitivity to light if the sap gets in the eye."
If you do not succeed to avoid the contact with this plant, and you or your children come in contact with giant hogweed, you should do the following:
In the unfortunate event that the sap comes in contact with your eyes, immediately flush with water extensively. Then be sure to wear sunglasses for protection!
If you touch the plant with a part of your body, wash affected area with cold water immediately, for the toxic reaction may begin within only 15 minutes. Then, make sure you get out of the sun! Apply a safe sunscreen on the affected area ASAP.