 Because the reactions involved in Bynesian decay require a certain quantity of moisture in the air in order for them to take place , keeping the air somewhat dry , i.e. keeping the environmental relative humidity under control is beneficial . This is achieved by careful monitoring of the relative humidity ( using instruments such as a hygrometer ) , and applying dehumidifiers when necessary ; sometimes , simple air conditioning systems may suffice . Extremely low humidity can damage some specimens , so caution is recommended . Usually , a relative humidity maintained around 50 % is considered to be adequate . Applying <unk> containing a strong base , such as potassium hydroxide , inside the storage environment to protect the specimens against degradation is also possible . Copy paper or KOH @-@ impregnated filter paper are some low cost examples of <unk> which can be used . These strong bases have a preference to react with acid , thus they compete successfully with the calcium carbonate specimens for any acidic vapors that may be present . The bases also help reduce the overall acid concentration inside the enclosed space . 
