Don't put cans in the refrigerator

[snopes]

Comment: My girlfriend's mom told her that you shouldn't put half used
cans of food in the refrigerator and then eat the food some days later
because you'll get botulism poisoning. I've been doing this for the past
25 years and I've never gotten botulism poisoning. I though how is a food
can any different that a metal pot that you cook with all the time? I've
heard that cans can get spoiled and that you shouldn't use a can that is
bulging or damaged, but if the food was good when you opened it, I think
it should be OK for a few days in the refrigerator.

Her mom has a lot of old wives' tales, and I hate telling her that I'm not
going to follow them.

[Troodon]

I too have been taught not to store food in opened metal cans.

[Nana M]

Storing open cans is a problem if the food is acidic. It reacts with the metal and affects the taste. Other than that, the only reason I can think of for it to be a danger is if the can was contaminated somehow and either spoiled the food that was in it, or contaminated other food by contact.

[JessBoo]

I started a thread about this on the old board- I'd seen a lot of American snopesters saying that you shouldn't leave open tins in the fridge. IIRC, most reasons were the same as Nana M said. We do it all the time though and never have a problem with it.

[BlueStar]

http://www.eatwell.gov.uk/keepingfoodsafe/storing/

Tin cans

When you have opened a can of food and you’re not using all the food straight away, empty the food into a bowl, or other container, and put it in the fridge.

Don’t store food in an opened tin can, or re-use empty cans to cook or store food. This is because when a can has been opened and the food is open to the air, the tin may transfer more quickly to the can’s contents.

This advice doesn’t apply to foods sold in cans with resealable lids, such as golden syrup and cocoa.

http://www.foodscience.csiro.au/storagelife2.htm

Food containing high concentrations of tin can cause nausea, vomiting, diarrhoea, abdominal cramps, abdominal bloating, fever or headache.

[Lainie]

Originally Posted by Nana M

Storing open cans is a problem if the food is acidic. It reacts with the metal and affects the taste.

I was specifically taught not to store pineapple or tomato products in an opened can, because of their high acid contents.

When I worked food service I was taught that about the cans, I was also told never to wrap stuff in foil for the same reasons. If the food is acidic, it will eat away the foil & get into the food. I have personally seen that happen myself.

If food is contaminated in the can, then transferring it to another container won't kill the organism. Bulging cans may indicate a buildup of pressure inside from gasses formed by bacteria such as Clostridium botulinum, and damaged cans may have compromised seals.