What is Hydraulic Fluid?
Hydraulic fluids are liquids used as the motive medium in hydraulic machinery and equipment. These fluids are used in a variety of machines, including automobiles. Car transmissions, power steering systems, and power brakes all require hydraulic fluids. Brake fluid, a subtype of hydraulic fluid, is specially made to have a low freezing point, a high boiling point, and hygroscopic abilities so it absorbs water. Hydraulic fluids are also used in tractors, excavators, forklifts, backhoes, bulldozers, garbage trucks, and other industrial machinery. Most aircraft flight control systems also require hydraulic fluid. Hydraulic fluids contain numerous chemical compounds, including oils, esters, silicones, butanol, polyalkylene glycols (PAG), corrosion inhibitors, and many others. The three most common types of chemicals used in hydraulic fluids, however, are polyalphaolefins (PAO), phosphate esters, and mineral oil. Luckily, the current interest in protecting the environment has created a dema
This Public Health Statement is the summary chapter from the Toxicological Profile for hydraulic fluid. It is one in a series of Public Health Statements about hazardous substances and their health effects. A shorter version, the ToxFAQs™, is also available. This information is important because this substance may harm you. The effects of exposure to any hazardous substance depend on the dose, the duration, how you are exposed, personal traits and habits, and whether other chemicals are present. For more information, call the ATSDR Information Center at 1-888-422-8737.
