I am not sure if there is any standard for outsourcing. But I have had experience in implementing offsite CSSD.
We stand by the principle of contain and confine in transportation of sterile and non sterile RMDs.
The knowledge of infection control in microbiology especially what will promote or accelerate growth of pathogenic organism. Then the decision of type of transport vehicle being designnto meet the infection control standard.
And many other logistic planning being done and implemented to ensure the offsite CSSD is meeting all standards. This is lengthy explanation and discussion. Happy to discuss this further with you