Generally speaking, participating in social security is recognized as work-related injury and disability in the insured place. If you don't buy social security, you will generally carry out work-related injury identification and disability identification at the location of the unit (so if the unit is in Songjiang, you can carry out identification and appraisal in Songjiang). And after the appraisal, an application must be made to the labor department applying for appraisal.
If you don't understand, please call for advice.