Pulmonary effects of a chemical, for reasons of space, time and economics, along with non-availability of sufficient quantities and/or sample tissues, can not always be tested following inhalation exposures. Uses of intratrachael administration involves methodology that is simple and uses relatively little material so that risk to laboratorians is much reduced (from an inhalation study). One can deliver relatively large amounts of material to the lung in a short period of time.

Overriding these advantages however, is the primary fact that amounts and sizes of particulate that would otherwise not be able to gain access to the lung, do so. The patterns of particle distribution in the lung following instillation are uneven and are unlike those resulting from inhalation. The nonuniformity is partially random but represents systematic and reproducible regional differences. Another serious problem is that the instillation technique totally bypasses the upper respiratory tract. Problems can result from altering dosing rates and the use of differing suspending agents. Despite the advantages stated earlier, these latter concerns have alerted the experimental inhalation toxicologist to the limitations of results obtained using this technique.