These are emissions that are not physically controlled and result from the intentional or unintentional releases of GHGs. They commonly arise from the production, processing, transmission, storage, and use of fuels and other chemicals, often through joints, seals, packing, gaskets, etc. (GHG Protocol Definition). For example - emissions from refrigerants, air conditioning, and refrigeration units.
If you do not know the exact amount of refrigerant added to the system, you can choose to simply uplift the total emission to 1%.