Should Formaldehyde (37%) be stored at 5 degrees C or lower? Will it damage the Formaldehyde?
In the cold some paraformaldehyde (formaldehyde polymer) or trioxymethane (a cyclic condensation product of three formaldehydes) may precipitate. It will depend on how much methanol has been added to avoid the polymerization products. Normally it will contain 10 to 15% methanol.
In reality, it is not necessary to store formaldehyde solution in the cold.
The MSDS for 37% aq formaldehyde says this: "Store in a segregated and approved area. Keep container in a cool, well-ventilated area. Keep container tightly closed and sealed until ready for use. Avoid all possible sources of ignition (spark or flame)" http://www.sciencelab.com/msds.php?msdsId=9924095
Combined with the answer below I would say not to store it cold.