What levels of humidity are acceptable for storing banknotes?

Appearnently if the levels of humidity are too low, papers usually don't like it as it will become very brittle and on the other hand, if there is too much humid, moulds might appear, which is not an acceptable damage.

Perhaps a humid level of 40-60% might sound acceptable???

As well as, does anyone happen to know an instrument that measures humidity levels?

I dont know the proper humidity level for storing banknotes..... Maybe you can store them in an unused cigar humidor. Set the temp and humifdity level to the right settings, and there should be no problem... lol......



KFC

You'd be looking for a hygrometer. They have analog and digital ones, and there are many types/price ranges. Look around on google for a few types. I only used one when I was working in a lab in Houston Texas a long time ago, as the high humidity would play havoc on my spectometer, but nowadays in less humid climate, and no more sensitive electronic equipment, I thought my days of hygrometers were over.

Perhaps I'm wrong. You pose a very valid question, and I might have to look into this myself.

Well... If no one has an answer to this pretty important question of what is the proper humidity, then I may just have to scour my engineering school for past research or do a little of my own

For a low end basic model, check your local pet store. Hygrometers are useful in the maintenance of many reptile/amphibian environments. I used them when I had my geckos back in the day.

I'd wager that as long as the humidity didn't get over 80% for prolonged periods your currency would be fine. I live in the south and it stays humid most of the time. I have some currency on ebay now that's been stored in boxes here in Arkansas for at least 50 years, no mold or mildew on any of it. At 80% ,you get into the area where molds, mildew, et. al. will thrive. Below 80% is fine. I don't know about a low end and causing paper to become brittle.Sounds like more research is in order.

Very interesting, no one seems to have an answer at the moment.

I mean, this can be a possible scenario - imagine if a man is moving from the tropics to the desert due to work etc, and the humid levels are going from some 90% to 30% or so. Transporting and storing banknotes over long period of time would be quite a nightmare!

National Vault, Inc., a document storage and retrieval service in Rochester, NY, recommends a relative humidity level of 35%-40%, with a temperature of 42º-45º.


I wonder if the humidity levels should be adjusted if higher temperatures are used?