The storage of microfilmed documents can significantly influence the estimated lifespan. While microfilm is not very sensitive to temperature and humidity, it can definitely be affected by them.
Storing microfilm in a very high temperature could lead to it melting. Of course, this would never happen in normal situations, therefore this risk only occurs in case of fire.
At the same time, a very low temperature won’t help as well. We think that a temperature of 18-20 degrees should be fine to maintain the integrity of the microfilm material and the content on it.
Relative Humidity of around 30-40% is recommended for storage, but it can go up to 50-60% also.