Heat transfer fluids and thermal oils are used to carry thermal energy in process heating, metal working, and machine cooling applications. There are several types of products. Circulating coolants, chiller fluids, anti-freezes, and refrigerants are used to transfer heat or provide cooling within machinery, process equipment or combustion engines. Hot oils, heater oils, and other thermal fluids are used to provide or transfer heat to a region near machinery or process equipment. Typically, products such as refrigerants, hot oils, and anti-freezes provide indirect heating or cooling and do not come into contact with the machinery or equipment. By contrast, metal working fluids and quenchants contact the workpiece or component directly. Most heat transfer fluids and thermal oils are used in circulating process heaters, chillers or coolers between a heat source and heat sink. Primary refrigerants provide cooling via phase changes or a Rankine cycle that consists of evaporative cooling and heat transfer. Secondary refrigerants include both circulating coolants and anti-freezes.