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')
@