Key words: risk assessment, irritation, research
Although procedures exist for developing health-based exposure limits (HBEL) for compounds based on systemic toxicity, there are no guidelines currently available for deriving these values based on local effects such as irritation. Since the critical effect produced by many compounds released from medical device materials will be manifested locally and not systemically, there is a need to develop guidelines for the derivation of HBELs based on local effects. Ethylene oxide is an example of a compound for which local effects become the significant adverse effect upon which the HBEL could be based, primarily when residues of this compound are present on small devices. To address this need, OST scientists are currently developing an approach that can be used to derive HBEL values based on local effects.