Aerogel is one of the most impressive materials humans have created. It holds the world record for the lightest solid material known to exist, consisting of up to 99.8% air. Commonly called "frozen smoke", it is safe to touch, hydrophobic (repels water), and an outstanding insulator. This is one of our most popular items and essential for any science enthusiast's collection. Great for gifting, collecting, or educational demonstration.What is it: Aerogels are a group of materials in which the liquid part of a gel has been replaced by a gas. This results in it having many fascinating properties, such the lowest thermal conductivity of any known solid, which means it makes a great insulator for Mars rovers and spacesuits. It also has extremely high porosity, which is why NASA has used aerogels to collect interstellar dust particles in outer space. About this sample: Available in 30mL tube, 1 gallon pail, or 55 gallon drum of high quality silica aerogel particles. Please allow additional lead time for drum orders. Tube net weight 0.08 oz (2.3g) CAS No.: 102262-30-6 Silica-based aerogels are non-toxic. However, since they repel moisture so efficiently, they can induce dryness of the skin, eyes, and mucous membranes. It is recommended that protective gear including respiratory protection, gloves and eye goggles be worn whenever handling or processing bare aerogels. Safety Data Sheet (pdf)