One wonders about questions like how long does dry ice last. To answer this question, first we must know what exactly dry ice is made off. The frozen shape of Carbon dioxide (CO2) is known as dry ice. It is sometimes referred to as Card Ice. Carbon dioxide is a component of the earth’s atmosphere. Plants use carbon dioxide during the process of photosynthesis and humans exhale this gas during breathing. The prime use for dry ice is as a cooling agent and it is used for keeping things in a frozen state. Dry ice changes states directly to gas without going through a liquid stage. This process is known as sublimation. How long does dry ice last depends on many things. The first thing to account for how long does dry ice last is the temperature at which the sublimation process begins. Dry ice sublimation takes place at −78.5 °C or −109.3 °F. Dry ice is never in liquid form. It has a very short shelf life thus it should be purchased closest to the time of intended use. It is dangerous to handle without using any sort of protection due to its freezing state and it may cause burns, injury and severe skin damage if handled without protective gear. Tongs and insulated gloves should be used to handle dry ice. If breathing around dry ice becomes hard then the vicinity should be vacated as soon as possible. Dry ice should be disposed of in a well ventilated area inside a container away from any pets or children.
Dry ice is manufactured relatively with ease. The snow like form of solidified carbon dioxide is packed together into either little pellets of dry ice or larger block formation. Larger block form of dry ice is usually required in shipping and smaller pellets of dry ice are reserved for small scale usage. The dry ice is mostly used for preservation of food and it is used for packing things that need to be kept frozen or cold.
Now we answer the question, how long does dry ice last? Well it depends on a few factors. Factors that affect the life of dry ice may include the size of the block of dry ice, the amount of dry ice and storage of dry ice. A well insulated container will increase the life of dry ice. Every 24 hours dry ice will sublimate at the rate of about 5 to 10 pounds. So for example if we require 15 pounds of dry ice to be used the coming day then we must purchase 20 to 25 pounds of dry ice the day before. Dry ice will last for 3 to 5 hours if left outside of its container. If left in liquid it will last only for 15 to 45 minutes because sublimation would be at an accelerated rate. If dry ice is kept in a cooler or ice chest then its life would be around 18 to 24 hours. Eventually the more dry ice that is present in a cooler, the longer it will last. If we want to extend the expiration date of dry ice then proper storage is essential. So the bottom line is how long does dry ice last depends upon its amount, its storage and its size.