Bests & Worsts Reviews from Amazon

Silica gel as a dessicant is a proven technique. It should work; however, after several days in a small gun safe (~7 Cu. Ft.) there was no reduction in the % relativity humidity (RH) from a freshly recharged Eva-Dry E-333 unit. I eMailed Eva-Dry support stating the conditions, i.e. 7 Cu. Ft., 60°F, 60% RH, asking for what reduction in RH could I expect at equilibrium. I received a response in 13 minutes: "There are too many variables to determine the reduction in the RH level. I can tell you we have sold thousands of E333 and E500 for safes. ..." The variables are volume, temperature, and amount of moisture in the air (RH) - not what I would consider to be "too many." While I did not expect an answer to 2 or more significant digits, I did expect a ball-park response. In my opinion, selling thousands of units is not a reliable indication of efficacy. As an aside, in 1998 the EU determined that cobalt chloride (the blue-orange indicator used in silica gel) is carcinogenic and its use was prohibited. In 2016, Eva-Dry changed to a different indicator. Old indicator blue = dry, orange = wet; new indicator orange = dry, green = wet. This was initially a source of confusion for me, as it was not explained well in the product description. It may confuse others.