ACUTE INHALATION TOXICITY IN RATS EXPOSED TO THERMAL-DEGRADATION PRODUCTS OF HYDRAULIC FLUIDS TYPE-C

The acute inhalation toxicity of the thermal decomposition products of Hydraulic fluids type C was assessed in rats. These fluids consist of a MixtUre Of water, ethylene glycol, polyalkylene glycol and some min or additives. Glissosafe(R) 610 was used as a model. Animals were expo sed for one hour to atmospheres resulting from spraying the fluid on a plate heated to 500-degrees-C, 600-degrees-C or 700-degrees-C. They w ere followed for fourteen days after exposure following the prescripti ons of the Sixth Report of the Safety and Health Commission of the Eur opean Community. Additional tests were done to follow the evolution of histological damage at one, two, three, five and seven days after exp osure to the different temperatures. These results were compared with some quantitative data of the major decomposition products. No mortali ty occurred. Only slight and transient respiratory discomfort was noti ced during exposure due to the presence of sensory irritating products . The effects on growth were virtually nil, except for some slight ini tial retardation during the first day post-exposure. Histological dama ge was most pronounced at a decomposition temperature of 500-degrees-C . These results correlated with the quantitative data of the sensory i rritating components. Out of this thermal decomposition mixture, forma ldehyde seems to contribute most to the toxic effects.