Is there any non-toxic and non-solvable-in-air liquid?
You may look at silicon Si and its derivatives. For example, the ethoxytriethylsilicane, or triethylsilicol ethyl ether is boiling at 153 °C. Or the tetraethylsilicane is also boiling at 153 °C. This last substance is used as a reference in NMR spectroscopy.