NDAs are used to protect both confidential information and trade secrets but trade secrets are treated differently from confidential information by the courts.

NDAs are used to protect both confidential information and trade secrets but trade secrets are treated differently from confidential information by the courts. In typical NDA you specify a defined period of time to avoid the risk of a court declaring that an NDA is too restrictive. This should not apply to trade secret. Trade secret lasts indefinitely even after NDA time period expires if all other conditions for trade secret are met. There are some cases where NDA expiring invalidates trade secret but it's mostly due to specific circumstances or badly formed NDA. You should inform the employees when they are dealing with a trade secret and use all means to keep them secret.