Does the sinus rinse powder have an expiration date? I have had mine for at least 5 years. Is it ok to use?

We are labeling for three years but all our internal inspection has shown that the saline mixture should have a five or six year year shelf life.� This is not an officially published statement�so we cannot take responsibility for the product after the expiration date printed in a red box on the bottom of the Sinus Rinse package.