Refrigerator oil composition and mixed composition for refrigerator

A mixed composition for a refrigerator, comprising:

• a refrigerant consisting of an unsaturated fluorinated hydrocarbon compound having the formula CxFyHz, where x is an integer of 2 to 6, y is an integer of 1 to 11, and z is an integer of 1 to 11, and the compound has at least one unsaturated carbon-carbon bond;
• and
• a refrigerator oil composition, comprising:
• a base oil (A);
• a phosphorus-based extreme pressure agent (B);
• a decomposition inhibitor (C) that inhibits the decomposition of an unsaturated fluorinated hydrocarbon compound in the presence of an iron;
• and
• an antioxidant (D),
• wherein the decomposition inhibitor (C) is a compound which controls the amount of fluorine in the refrigerator oil composition at 30 ppm by mass or less after mixing the refrigerator oil composition and R1234yf at a mass ratio of 1:1, and subjecting the mixture to an autoclave test at 175° C. for 336 hours in the presence of a metal catalyst consisting of iron, copper, and aluminum, and
• wherein the decomposition inhibitor (C) is at least one selected from the group consisting of perbasic calcium salicylate, sodium borate, and 8-quinolinol,
• wherein the content of the decomposition inhibitor (C) is 0.001% by mass to 0.50% by mass based on the total amount of the refrigerator oil composition.