Which could produce a mixed waste?

Mixed waste is defined as waste that contains both radioactive materials and other hazardous substances, typically chemical waste. The option identifying the use of certain types of chemicals to perform decontamination is pertinent because certain decontaminants can have properties that qualify them as hazardous waste, particularly when they come into contact with radioactive materials.

For instance, if a decontamination process involves the use of a chemical that is classified as hazardous, and it is used to clean an area that has been contaminated with radioactive substances, the resultant waste would then fall into the category of mixed waste. This is critical for radiation safety officers as handling mixed waste requires specific protocols due to its dual nature, which can present unique risks both from radiation and the toxicological properties of the chemicals involved.

The other options do not lead to the creation of mixed waste. Biodegradable materials imply organic waste that doesn't typically contain radiation. Non-toxic cleaning agents would be safe and would not introduce hazardous chemicals into the waste stream, and storing organic and inorganic materials separately relates to waste segregation rather than mixing different types of hazardous and radioactive materials.