Engine powered forklifts emit carbon monoxide which can kill. This includes propane forklifts.
When are you most likely to be exposed to this? When you are driving your forklift in and out of trailers or indoors hazardous concentrations can build up very quickly.
How do you feel? The symptoms of CO poisoning are nausea, headache, and dizziness.
What can you do? Limit your exposure and don’t leave the engine idling.
Or get an electric forklift!