If your blender has a Clean cycle, just add a cup of water and a drop or two of dish soap to your jar, replace the lid, run the cycle, and rinse. If your blender does not have a Clean cycle, add the same amount of water and soap, replace the lid, Pulse a few times, and rinse.
Safety is our top priority. Blendtec blenders are among the most powerful on the planet, and their jars have to handle high-speed impacts from very hard ingredients like frozen fruit. Glass jars have the potential to shatter not only when dropped, but also during high-speed blending. Blendtec's Tritan copolyester jars are engineered to withstand that kind of stress.
Lighter is better. Blendtec jars are very light and are molded for easy gripping and storage. Glass jars, on the other hand, are heavier and more difficult to grip, pour, and store.