Inhalation Threshold of Concern (TOC) Research
Rick Davis is conducting research to develop a threshold of concern (TOC) for inhalation toxicity. He has compiled a repeat exposure inhalation toxicity database of over 350 chemicals. Analysis of the database shows that inhalation TOCs are very close to oral TOCs for chemicals causing systemic critical effects. This is not true for chemicals that cause local critical effects such as upper respiratory tract irritation. This work was presented at the Society of Toxicology annual meeting in March 2006. To receive a copy of the presentation, contact Dr. Davis at ToxSolutions. Work to develop a classification scheme and inhalation TOCs for local effect chemicals is now in progress. Development of inhalation TOCs for all chemicals with potential inhalation exposure will save time, money and laboratory animals when assessing very low inhalation exposures. The method will be analogous to the FDA threshold of regulation for food additives, the NSF/ANSI threshold of evaluation used for chemicals imparted to potable water and other applications of TOCs in the EU and JECFA.