Gold testing - life of acids

HOW LONG DO THE ACIDS LAST?
Acids for testing precious metals. How long do gold-testing acids last? How should they be stored?

ACIDS SHELF LIFE / USE-BY DATES

USE-BY DATES - SUMMARY

 The white, blue and amber fluids last between 1 and 1½  years.

 The green fluid lasts about a year.

 The clear fluid lasts about 10 months.  

 USE-BY DATES - DETAIL

For the white(9ct) and blue(high carat) acids the use-by dates gives about 18 months.  They get weaker over time, until the reactions become painfully slow and, eventually, everything shows up as gold. To be on the safe side (and for ease-of-use) it is wise to replace these bottles in a year. 

For the amber(silver) fluid the use-by date gives about 16 months. If it goes a blackish colour, it’s gone off and should be discarded immediately. To be on the safe side it is wise to replace these bottles in a year.

For the green(white metals/platinum) fluid the use-by date gives about 13 months.  This one tends to go off suddenly rather than give slower reaction times. To be on the safe side it is wise to replace these bottles in less than a year.

For the clear(8ct/high zinc) fluid the use-by date gives 10 months.  This one is very sensitive, it goes off easily (e.g. if stored in daylight), to be on the safe side it is wise to replace these bottles in 9 months.

NOTES

Any trader who buys gold regularly will use up the acid long before the use-by date.

Acids will last until at least the use-by date if stored correctly. Keep them tightly capped when not in use, store them in their secure box (out of the light, especially the clear fluid), avoid extreme heat (e.g. a sunlit window or a hot car), do not mix up the caps.

Acids don't suddenly go off on the use-by date, the reactions become slower over the months and years, so you may wish to continue using them until the reaction times become painfully slow or until you get misleading results. It is, of course, better to get fresh bottles rather than wait until they are so old that you get misleading results.

If you are using or storing more than one bottle, take care to use up the oldest first.

If you are a wholesaler or if you are buying in bulk and sending the bottles out to your stores, take care to sell / send the oldest first.

We are the manufacturers, we will always send you bottles from the latest batch, but we cannot replace outdated bottles, even if you have only used them a few times.