Poisonous Plant Safety program covers the different types of plants and what to do if you are exposed. Poisonous plants in one form or another can be found throughout the United States. The prime hazard is the allergic reaction resulting from contact with the resin produced by the plants. Many outdoor occupations such as tree trimmers, landscapers, surveyors, park and highway maintenance, meter readers, and fire fighters face frequent exposure concerns. The best way to avoid exposure is your ability to identify the plants in your region and avoid contact.