Servoaquol oils are oil-in-water type fire resistant hydraulic fluids specifically developed for hydraulically operated mining pit-props. They form stable emulsion with water and give long satisfactory service life in hydraulic systems. Servoaquol 250 and Servoaquol 750 have been developed to meet former National Coal Board, UK specification NCB 463-1981 for grade 18 and grade 19 respectively and also IS:10532 (Part I)- 1983 (Reaffirmed 2004), HF-A Grade 1 and HF-A Grade 2 respectively. Servoaquol 250 and Servoaquol 750 meet the requirements of Director General of Mines Safety, Dhanbad.