Quote from the Canadian Diabetes Association:
The insulin vial you are using each day is quite stable at room temperature (25 C/77 F) for one month. Cartridges are stable for 21 days. Extra insulin stored in the refrigerator is good until the expiry date. Never store extra insulin in the freezer. Freezing can damage insulin and the insulin should not be used if this has occurred. Keep insulin away from heat and strong light. Never store your insulin in the trunk or in the glove compartment of your car.
Always check your insulin solution to ensure that the appearance is normal.
All cloudy insulin should appear uniformly cloudy when mixed by rolling between your hands. If particles are floating in the insulin solution or adhering to the bottom or sides of the bottle, do not use this insulin. If the short-acting insulin solution is no longer clear and colorless, discard the bottle.
Check this site out (Canadian Diabetes Association)
http://www.diabetes.ca/about_diabetes/insulin.html
An American Diabetic Association recommended webpage:
http://www.insulinchoice.org/insulin/storage.htm
Quote from the American Diabetic Association:
*can be found at
http://www.diabetes.org/main/type1/medical/insulin/about_insulin.jsp*
Storage and safety. Using cold insulin can make your shot more painful. You can keep the bottle of insulin you are currently using at room temperature or warm the bottle by gently rolling it between your hands before you fill the syringe. If you buy more than one bottle of insulin at a time, store the extra bottles in the refrigerator until you start to use them.
Never store insulin at very cold (under 36 degrees Fahrenheit) or very hot (over 86 degrees Fahrenheit) temperatures. Extreme temperatures destroy insulin. Do not put your insulin in the freezer or in direct sunlight.
Insulin may lose some potency if the bottle has been opened for more than 30 days. Look at the bottle closely to make sure the insulin looks normal. If you use regular, it should be perfectly clear-no floating pieces or color. If you use NPH or lente, it should be cloudy, with no floating pieces or crystals on the bottle. Do not use insulin past the expiration date
American Diabetes Association Website:
http://www.diabetes.org/main/application/commercewf
I firmly believe that insulin should be stored in temps between 2-8degrees never in a freezer, away from sunlight and heat, and bottles currently in use can be left out in normal indoor conditions but should be discarded once left out for more than 30 days, cold insulin shots are painful.