Inhalation exposure technology used for varying exposure modes and profiles in toxicology studies

Current technology used in inhalation toxicology studies employs various exposure modes and concentration profiles. Inhalation exposure modes typically utilize wholebody techniques, whereas other exposure modes include nose- and head-only exposure systems and, in some cases, whole- or partial-lung exposure systems. The latter two conditions are utilized when safety considerations are warranted by the hazardous nature of the chemical or agent being tested, the test substance may be dermally adsorbed, and/or the costs of the chemical used are of concern. Inhalation exposure studies may span several minutes to 24 h of continuous exposure and from one day to the full life span of the animal being tested. Time-varying profile exposures, on the other hand, are typically used to mimic human exposures to chemical agents and, in some cases, to more accurately extrapolate animal toxicity data in assessing human risk. Automation of inhalation exposure systems has expedited the timely operation of both accurate and repeatable profiles, and it has allowed for reexamination of classical time-weighted average concentration information relating to human health concerns. The toxicological assessment of potential health effects resulting from exposure to airborne substances typically involves thorough characterizing of the test agent via acute, subchronic, and chronic toxicity testing.