Acute Inhalation Toxicity in Rats Exposed to Thermal Degradation Products of Hydraulic Fluids Type C

Abstract

The acute inhalation toxicity of the thermal decomposition prod ucts of Hydraulic fluids type C was assessed in rats. These fluids consist of a mixture of water, ethylene glycol, polyalkylene glycol and some minor addi tives. Glissosafe® 610 was used as a model. Animals were exposed for one hour to atmospheres resulting from spraying the fluid on a plate heated to 500 °C, 600 ° C or 700°C. They were followed for fourteen days after exposure following the prescriptions of the Sixth Report of the Safety and Health Commission of the European Community. Additional tests were done to follow the evolution of histological damage at one, two, three, five and seven days after exposure to the different temperatures. These results were compared with some quantitative data of the major decomposition products.

No mortality occurred. Only slight and transient respiratory discomfort was noticed during exposure due to the presence of sensory irritating products. The effects on growth were virtually nil, except for some slight initial retardation during the first day post-exposure. Histological damage was most pronounced at a decomposition temperature of 500°C. These results correlated with the quantitative data of the sensory irritating components. Out of this thermal decomposition mixture, formaldehyde seems to contribute most to the toxic ef fects.

Keywords

hydraulic fluid type C inhalation toxicity rats thermal decom position.

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References

Commission of the European Communities-Safety and Health Commission for the Mining and Other Extractive Industries. 1981. Sixth Report on the Specifications and Testing Conditions Relating to "Fire Resistant Hydraulic Fluids Used for Power Transmission in Mines," 2786/8/SIE, Luxembourg.

Benthe, H. F. University of Hamburg, personal communication.

Van Dam, J. and P. Daenens. 1992. "Evaluation of the Thermal Decomposition Apparatus Used for Toxicity Testing of Hydraulic Fluids," Journal of Analytical and Applied Pyrolysis, 23:43-56

. Van Dam, J. and P. Daenens. 1993. "The Effects of Thermal Degradation Products of Hydraulic Fluids Type C on the Carboxyhaemoglobin Level in Wistar SPF Rats," Journal of Fire Sciences, 11:394-406

. Daniel, H. , J.P. Henin , J.P. Lefevre , R.J. Millischer and P. Gervason. 1989. "Acute Inhalation Toxicity in Rats Exposed to Thermal Degradation Products of a New Chlorinated Fluid for Electrical Transformers," Journal of Fire Sciences , 7:81-93

. NIOSH Manual of Analytical Methods, 3rd Edition, Vol. 1, Method 2502.

Kane, L.E. and Y. Alarie. 1977. "Sensory Irritation to Formaldehyde and Acrolein During Single and Repeated Exposures in Mice," Amer. Ind. Hyg. Assoc. J., 38:509-522

. Kane, L.E. , C.S. Barrow and Y. Alarie. 1979. "A Short-Term Test to Predict Acceptable Levels of Exposure to Airborne Sensory Irritants," Amer. Ind. Hyg. Assoc. J., 40:207-229

. Bos, P.M.J. , A. Zwart , P.G.J. Reuzel and P.C. Bragt. 1992. "Evaluation of the Sensory Irritation Test for the Assessment of Occupational Health Risk," Crit. Rev. Toxicol., 21(6):423-450

10.

. Morikawa, T. 1989. "Toxic Hazards of Acrolein and Carbon Monoxide During Combustion," in Advances in Combustion Toxicology, Volume 1, Gordon E. Hartzell, ed., Lancaster, PA: Technomic Publishing Co., Inc., pp. 156-166.