Yes. It really depends on what it is.
No, salt does not go bad after the expiration date. Salt is a mineral that does not spoil or expire.
No, salt does not have an expiration date. It is a mineral that does not spoil or go bad over time.
Morton Salt does not have an expiration date. It is a stable product that does not spoil or go bad over time.
there is no expiration date however it may go flat. but, if it was stored correctly it shouldn't ever go bad.
The expiration date is the last date on which the manufacturer is willing to guarantee that it is good. After that date, it may or may not be good (for that matter, it's possible for it to go bad BEFORE the expiration date, though this is not terribly likely).
Sea salt does not have an expiration date if stored properly in a cool, dry place. It can last indefinitely without going bad.
Normally once the date expires, it takes about a week before it goes bad.
check the expiration date
Does oxaprozin go bad
The expiration date on most drugs tell you when the manufacturer is guaranteeing it will have the maximum potency. Taking a drug after the expiration date is taking a chance that it won't be as effective as a drug taken within the "guaranteed effective." So, in answer to your question, on the diphenhydramine, no one knows if it is safe. All you can say for sure, is the manufacturer will not guarantee the drug is 100% effective after the expiration date.
I think if you leave it open long enough then it might go bad, but probably not. Does pen ink have an expiration date? I don't think so.
You can tell if eggs are bad by checking the expiration date, smelling for a sulfur-like odor, and observing the appearance of the egg white and yolk. If the eggs are past the expiration date, smell bad, or have discolored or runny whites and yolks, they are likely bad and should not be consumed.