Signs of propane poisoning from breathing in or swallowing include palpitations, headaches, nausea, convulsions and numbness in the limbs, according to MedlinePlus. Additional symptoms include dizziness, coughing, skin irritation and shallow breathing. When the propane poisoning occurs through direct contact, symptoms are similar to those of frostbite.
Propane is a clear, odorless and flammable gas, explains MedlinePlus. When a person ingests or inhales propane, it replaces oxygen in the lungs. This makes breathing difficult and may cause suffocation. Additionally, long-term exposure to propane may lead to a stroke, coma or death. When propane poisoning occurs at home, those attending should call 911 for emergency medical assistance.