Use following SQL to find out the ISOLATION LEVEL used by DB2 packages.

SELECT 'SHOW_RSETS' "STORED PROCEDURE",
        SUBSTR(PKGNAME,1,18) PACKAGE, 
       "ISOLATION" 
FROM   syscat.packages 
WHERE  pkgname = (SELECT deps.bname PACKAGE
                  FROM   sysibm.sysdependencies deps,
       	                 sysibm.sysroutines procs
                  WHERE  deps.dtype = 'F' 
                  AND 	 deps.btype = 'K'
                  AND 	 procs.specificname  = deps.dname
                  AND 	 procs.routineschema = deps.dschema
                  AND    procs.routinename   = 'Stored_Procedure_name')
@