Division II.6.6.2.4.1

For substances that are not absorbed following oral ingestion, systemic exposure is negligible (or even non-existent). For such substances it is not possible to establish a conventional oral NO(A)EL or BMDL and ADI. The risk assessment for these types of substances shall normally rely on demonstration of the absence of oral bioavailability in suitable models or, where appropriate, through proof of degradation and/or inactivation under gastric conditions (likely to be demonstrated in in vitro models). In addition, for such substances, possible local effects on the gastrointestinal system (including microbiological effects on the colonisation barrier) shall be addressed.