Nuby straws have the same characteristics as our silicone spouts and nipples. Frequently used spouts/straws will begin to show signs of wear over time. We recommend that you replace these items regularly. In addition, Nuby uses the safest most durable silicone available; however, it is necessary to check these items before each use and replace them immediately if there are any signs of wear or damage! Keep in mind that children who are teething might damage a nipple/spout faster than others, since the new teeth of a child are very sharp. Replacement spouts and straws are available so your child can continue to use their favorite cups. Nuby uses the safest most durable Silicone available; however, it is also important to use the appropriate spout/straw for the appropriate age of the child.