Geography

• There are only a few places in the United States where poison sumac doesn't grow including Alaska and Hawaii. The plant also has difficulty growing in extremely hot areas, such as the desert.
  
  

Potency

• It takes only one nanogram of the oil from poison sumac to cause a reaction, but most people who come in contact with the plant absorb around 100 nanograms of oil.
  
  

Workers Compensation

• A reaction to poison sumac is actually covered under workers' compensation in California and other states because the severity of the reaction is bad enough that it often prevents the person from working.
  
  

Dead Plants

• Even after the poison sumac dies, it's still possible for the oil to sit on the leaves, the stem and any other surfaces of the plant. This oil can last for up to 5 years and cause a reaction.
  
  

Identification

• You can identify poison sumac from the number of leaves on the branches. The plant usually has seven leaves or more on each branch, while poison ivy comes in clusters of three.