or external thermometer, even if the unit has temperature controls, in case there is a malfunction and to ensure that the internal temperature of the food meets government regulations. Oil filtration An oil filtration system, chemical treatment, or absorbent powder (diatomaceous earth or synthetic magnesium silicates) all help remove tiny food particles that are not always visible. Using these systems doubles the life of the oil. Oil filtration systems can sometimes be purchased as an enclosed part of the fryer to avoid involving employees in the somewhat dangerous process of filtering the oil with an exterior system. Many restaurants use a portable oil filtration system to transport waste oil to a disposal area. However, even old oil is not completely useless. There are ways (involving other chemicals and machinery) to "recycle" old oil as biodiesel that can power diesel vehicles. Bio-diesel increases energy security resulting in many environmental benefits and even helping decrease greenhouse emissions. Pouring used oil, such as fats and grease, down the drain should be avoided, as this can cause food build up and clogged pipes, restricting the flow of liquids. This often results in costly restoration and cleaning. Accessories Deep fryer accessories are products that are designed to improve the process of frying. A typical accessory of a deep fryer is the frying basket, which holds items to be fried and lets users take the food out of the fryer without using other tools. A skimmer is a screen (either coarse, medium, or fine) attached to a handle and used to remove food from the fryer. A thermometer is an essential accessory of a deep fryer because the temperature is critical to get the best-tasting food and ensure that the food is cooked to an appropriate temperature. To make sure the fryer itself stays in good condition, a cleaning solution is required, while a pump and filter can help to keep the oil clean. Cleaning brushes help to scrape away burnt bits of food from the sides and bottom of the fryer without damaging it. Automated deep fryers The automated deep fryer has a different system that incorporates a single basket unit or double basket unit, which could be useful in loading, cooking, and serving food. The refrigerated storage compartment has a portion controller and dispenser, a separate cooking chamber having a frying vessel. Most automated deep fryers include an air filtration system which gets rid