It?s a killer you can't see, taste or smell. Carbon monoxide poisoning can happen due to gas powered tools running in a confined space. But with common sense precautions, workers can stay safe. / / Carbon monoxide (CO) is the invisible gas given off from burning fossil and wood fuels. Even in small concentrations, it reduces oxygen carried in the bloodstream. Symptoms of headaches, dizziness and confusion come on quickly, often leaving no time to escape to fresh air. / / Workers will be safe from carbon monoxide poisoning if they use the correct tools and have CO training. Also critical are ventilation, monitoring, safety signs, and, if necessary, a breathing apparatus.