Is it the best and safest to temporarily fill liquid nitrogen in a thermos cup with 304 steel liner?

It is safe to fill the thermos cup with 304 steel liner with liquid nitrogen for a short time. Liquid nitrogen is an inert, colorless, tasteless, non-corrosive, non-flammable and extremely low temperature liquid, which will not have any negative impact on 304 steel.

However, it should be noted that the storage time of liquid nitrogen is limited, and it is only suitable for temporarily storing a small amount of liquid nitrogen. If a large amount of liquid nitrogen needs to be stored for a long time, it is recommended to use a professional liquid nitrogen tank. In addition, after filling with liquid nitrogen, the lid of the thermos cup should not be sealed too tightly, and a gap should be left for the liquid nitrogen to vaporize and volatilize to prevent the explosion.

The above information is for reference only. It is recommended to consult experts in relevant chemical fields to obtain accurate information.