Hazards
The sap from Giant Hogweed is known to cause sever skin rashes that are hyper-sensitive to sunlight. Skin sensitivity can persist for months.
First-Aid
After skin contact with sap, wash the skin fully with soap and water and keep the exposed areas away from sunlight for at least 48 hours. If significant blistering develops, consult a physician. Application of an anti-inflammatory cream (e.g., a 0.5% hydrocortisone cream) may reduce skin irritation. In the following months, a sun block cream should be used on sensitive areas. If the sap gets into the eyes, flush with copious amounts of water and then consult a physician.
Risk Management
Wear heavy, water-resistant gloves when handling the plants. Remember to dispose of the gloves after use (heavy rubber gloves can be re-used if carefully washed with soap and water). Do not get any sap on your exposed skin! Wear water-resistant coveralls or clothing that leaves no skin exposed. Clothing may soak up the plant sap, which can then penetrate into the skin. Plant bristles may also penetrate thin clothing. Wear goggles when disturbing or removing the plants, as small droplets of sap may be released into the air.