The Nuby Wide Replacement spouts come wrapped in a sealed baggie direct from the factory. It is important that you do not allow your child to chew on these spouts as that is not what any nipple or spout was made for unless noted that way. It doesn't matter what the brand is, the warnings are all the same.
If your baby or toddler chews too many times, any silicone or latex spout will wear out and possibly break off into little pieces. This could cause a choking hazard, so it's important that parents or guardians supervise their children when they are using their sippy cups. If you see excessive chewing, then take the cup away and substitute the sippy cup with a pacifier, a toy or a book or another diversion. This method works.
In addition, it's very important that the valves don't get broken in the spouts. The valves are designed to keep the sippy cup from dripping. If you look at the Nuby wide replacement spouts carefully, you will see two oval shaped openings in the top. Those openings are delicate and when your baby chews on them and breaks them, the liquid will pour or drip out.
In addition, if you are cleaning the spouts, don't use a sharp object or a nipple cleaning brush to clean them. It's much easier to rinse them out right away, soap them, and then use a higher force of water to clean any remaining liquid residue out. You can also put these in the dishwasher as they are dishwasher safe.
Nuby sippy cups are among the most popular sippy cups in the world and if taken care of properly, will last well beyond your baby's years. The Nuby wide replacement spouts are wonderful because they help save our landfills since you can use your sippy cup over and over again without having to throw it away.