Worker health and safety in solar thermal power systems. VII. The toxicological and health implications of solar thermal process fluids

Abstract

The toxicological and health implications of high-temperature solar thermal process fluids were examined. Fluids likely to be used were first identified and characterized according to their physical and chemical characteristics. The identified fluids were then screened to select those solar thermal process fluids with potentially significant toxicological/health implications for further study. The screening procedure delineated each compound's basic chemical, physical, and operating characteristics (as would occur in high temperature solar thermal applications), selected toxicological information and the criteria used to classify each compound according to a broad toxicological rating scheme. Thirty compounds determined from the initial screening procedure to be moderately to highly toxic were selected for further study. The detailed toxicological assessment consisted primarily of a comprehensive literature survey. Effects resulting from acute and/or chronic exposure were evaluated and applicable federal exposure standards were identified and discussed. Particular emphasis was placed upon determining both the toxicity of the selected compounds as they relate to the solar thermal industry and the following factors: type(s) of organism exposed, means of entry into the body, level and period of exposure, fate in the body, and observed effects. To provide perspective to the toxicological evaluation, the health and safety experience of the solar thermal industry and other industries with processes or fluids similar to those proposed for the solar thermal industry was evaluated. Three related industries with processes similar to the solar thermal industry - electric utility, petroleum refining and chemical process industries - were identified and evaluated in detail. Two specific processes within those industries, the transport of fluids and the transport of heat, both at high temperatures and pressures, were examined.