Source: United Parcel Service 

United Parcel Service (NYSE:UPS) may seem too big and brown to fail, but that's simply not true. Even big companies can have big risks. With $35 billion in assets, 435,000 employees, and operations in 220 countries and territories, UPS has a lot to manage.

In every annual 10-K SEC filing, corporations have to list their biggest risks. Here are five of the biggest risks UPS thinks it (and its shareholders) has to handle.