DERMAL ABSORPTION OF CHEMICALS FROM LIQUID MIXTURES

描述：工作场所是皮肤接触有害化学物质最常见的场所之一。识别皮肤接触危害是控制皮肤接触危害的关键。不幸的是，目前对化学物质作为皮肤吸收危害的识别是不一致的，缺乏记录和定性。结果，那些负责在工作场所保护人类健康和安全的人被迫在很少或根本没有信息的情况下，对安全或危险水平以及所需的个人保护类型作出判断。本研究的最终目的是为职业安全和健康从业者提供关于职业皮肤暴露潜在危险水平的改进指导。虽然大多数职业性皮肤接触涉及化学物质的混合物，但多种成分与皮肤之间的相互作用仍然未知。拟议的研究旨在识别和理解

DESCRIPTION: The workplace is one of the most common venues for hazardous chemical contact with skin. Recognition of the dermal exposure hazard is essential for its control. Unfortunately, the present identification of chemicals as skin absorption hazards is inconsistent, poorly documented, and qualitative. As a result, those charged with protecting human health and safety in the workplace are forced to make judgments about safe or dangerous levels, and the type of personal protection required, with little or no information. The ultimate goal of this research effort is to provide occupational safety and health practitioners with improved guidance regarding potentially dangerous levels of occupational dermal exposure. While most occupational exposures of skin involve mixtures of chemicals, the interactions between multiple components and skin remain unknown. The proposed research is directed toward identifying and understanding the effect of exposures to chemical mixtures and especially non-aqueous solutions. Understanding that experimental evaluations will be limited to a small fraction of all mixtures encountered occupationally, we propose to develop a fundamental understanding of the underlying mechanisms by combining data with mathematical models. Specifically, we will (i) examine experimentally the extent to which several test solutes in water and in four non-aqueous solutions (toluene, n-octanol, n-octane and a selected chlorinated hydrocarbon) interact with each other or skin to alter the rate and/or amount of chemical absorption, (ii) develop computational procedures for estimating dermal absorption from aqueous and non-aqueous solutions containing two or more organic compounds, and (iii) demonstrate and use a new method for measuring electrochemical impedance to characterize skin barrier function and the effect of non-aqueous solutions thereon. Initial studies will involve four solutes (naphthalene, phenanthrene, 1-naphthol, and 1,3-naphthalenediol) in toluene and n-octanol. This combination of solutes and solvents were selected to examine interactions between similar and dissimilar chemicals, and to assess the importance of hydrogen bonding interactions between absorbing chemicals and skin. The ultimate goal of this research effort is a framework for relating dermal absorption measurements and predictions for liquid mixtures to industrial health scientists in the form of useful guidelines. With such information in-hand, it will be possible to plan effective exposure controls and/or interventions.