The effects of normal and adverse environmental holding conditions on the formation of cholesterol oxidation products (COPS) in powdered cheeses and salted and unsalted butteroil were investigated. Little or no change in COPS levels was noted in a variety of powdered dairy products stored at 4, 21, or 38°C for up to 6 months. Storage for 18 mo at 4°C resulted in a three‐fold increase in the levels of COPS. Cheddar cheese powder continuously exposed to light (1611 lx) displayed increases in α‐epoxide and 7‐ketocholesterol through week 3, thereafter declining to a level at week 9 of about one‐half of that seen at week 3. Continuous heating of butteroil (110°C) caused large increases in COPS' levels, with unsalted butteroil exceeding levels found in salted butteroil by 2‐ to 3‐fold.