From the internet, DEF info site.
Is Diesel Exhaust Fluid (DEF) corrosive?
Diesel Exhaust Fluid (DEF) is not toxic, harmful or dangerous. In fact, of all the fluids used in a truck, such as diesel, engine oil, brake fluid, antifreeze and windscreen wash, DEF is the least hazardous. However, DEF is corrosive for some metals such as carbon steel, aluminum, copper and zinc, and DEF should not be stored in containers made of these materials. Your DEF supplier can advise you further. ISO22241 provides a list of materials that are recommended and not recommended, but makes it clear that neither list is exhaustive.
Do I need to wear protective clothing when filling up the DEF tank?
Wearing protective clothing is not necessary when handling DEF, however, Diesel Exhaust Fluid (DEF) can stain clothes. If you do spill any DEF on your clothing, rinse it off with water.
What should I do if a spill DEF?
If you spill a small amount of Diesel Exhaust Fluid (DEF), it can be washed away with water or wiped up. If you leave it to dry it will turn into white crystals. These can be washed away with water. If you spill a large