Do the laboratory chemicals AR have an expiration date?
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Do the laboratory chemicals AR have an expiration date?
Yes, there is, but it’s expired yet it still works fine
There must be an expiration date; it seems that there are no standards in this regard yet Who has the standards? Please share them.
Does anyone with relevant standards have them to share?
I think reagents with stable chemical properties (such as sodium chloride) can be used continuedly; for reagents whose stability is uncertain, it’s better not to use them once their expiration date has passed.
If there is no requirement for stable quality, there should be no fixed shelf life.
Laboratory chemical reagents come in a wide variety, each with different properties. Some stable salts and oxides can be stored for thousands or even tens of thousands of years without any problem; examples include calcium carbonate, sodium chloride, silicon dioxide, aluminum oxide, etc. In particular, certain silicates have been present on Earth for 4 billion years. But this is not necessarily the case for all reagents; those that are volatile, prone to oxidation, or even subject to decay certainly have a limited shelf life. There are also some reagents that may start to change or even degrade as soon as they are prepared, such as Grignard reagents and Karl Fischer reagents, which are changing at all times.