Yes carbon dioxide even in liquid form is dangerous to humans health and cause cause death in large enough concentrations.
So if you're working with or around liquid carbon dioxide you need to be very careful and know what you're doing when working with the carbon dioxide or working around it even in liquid form.
If you get exposed to the liquid or other carbon dioxide in enough concentrations you can become very sick and experience things such as nausea, dizziness, headache, mental confusion, increased blood pressure and respiratory rate.
Exposure to liquid or other carbon dioxide in concentrations above 8% nausea and vomiting appear and above 10%, suffocation and death can occur within minutes.
So be very careful and seek medical attention and get into some fresh air if you become exposed to the carbon dioxide.