How long can I keep evaporated milk, sweetened condensed milk, and powdered milk?

These water-extracted milk products, commonly used for cooking and baking, are heat-sterilized and canned for a longer shelf life than regular milk. Evaporated milk (half the water content removed) and sweetened condensed milk (half of water content removed, then sweetened) have a shelf-life of about 1 year at room temperature. Cans are best stored in a cool, dry area and inverted every 2 months to avoid separation of water and solids, according to the National Dairy Council. Unopened, they are safe as long as the cans are intact; however, they may thicken, carmelize, and turn brown with time.
 
Once opened, canned milk should  be poured into a covered opaque container, refrigerated, and used within a few days. 
 
Cans of Nestle Carnation Evaporated Milk carry a "best before" date, and Nestle doesn’t recommend using the product beyond that date for quality reasons.  
 
Powdered milk (water extracted entirely) has a shelf life of 6-9 months when stored at lower than 80° F and less than 65% relative humidity. But the protein and sugars in powdered milk, whether opened or not, react over time to cause it to brown and become clumped and off-flavored.
 
Nonfat dry milk has a shelf life of 12-18 months under the conditions described above.
 
Once opened, dry milk should be stored  in an airtight container. Refrigerated reconstituted milk should be used within a few days.
 
Source(s):
National Dairy Council Factsheet: “Newer Knowledge of Dairy Foods--Protecting the Quality of Milk and Other Dairy Foods” 
Very Best Baking.com (Nestle corporate website) “Commonly Asked Questions” 
Susan Brewer, Ph.D. University of Illinois, Department of Food Science and Human Nutrition