Question

If a chemical (in general) bottle says on its label would be expire in 12 months from now (example). Is it possible that chemical bottle can be expired in 9 months (3 months shorter) if that chemical bottle in use and still close its cap after use?

Answer 1

Yes, It can be expired earlier than expected date of expiry.

Chemicals get expired mostly due to a unwanted reaction, oxidation (reaction with oxygen when exposed to air) to be specific.

When the bottle is opened and used, the remaining part of the bottle get filled with air. Hence the chemical inside the bottle get exposed to air.

This will result in oxidation of the chemical inside the bottle. Eventually the chemical composition will change and an unwanted chemical will be formed inside the bottle. That is, the chemical get expired.

This is the normal case. In case, if another impurities (which may potentially catalyze this oxidation reaction) gets added to the chemical accidentally, then the rate of oxidation reaction may increase and the chemical may be expired in very short period of time.