The smoke point generally refers to the temperature at which a cooking fat or oil

Cooking oil

Cooking oil is purified fat of plant origin, which is usually liquid at room temperature ....

 begins to break down to glycerol

Glycerol

Glycerol is a simple polyol compound. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. The glycerol backbone is central to all lipids...

 and free fatty acids, and produce bluish smoke. The glycerol is then further broken down to acrolein

Acrolein

Acrolein is the simplest unsaturated aldehyde. It is produced widely but is most often immediately reacted with other products due to its instability and toxicity...

 which is a component of the smoke. It is the presence of the acrolein that causes the smoke to be extremely irritating to the eyes and throat. The smoke point also marks the beginning of both flavor and nutritional degradation. Therefore, it is a key consideration when selecting a fat for frying

Frying

Frying is the cooking of food in oil or another fat, a technique that originated in ancient Egypt around 2500 BC. Chemically, oils and fats are the same, differing only in melting point, but the distinction is only made when needed. In commerce, many fats are called oils by custom, e.g...

, with the smoke point of the specific oil dictating its maximum usable temperature and therefore its possible applications. For instance, since deep frying

Deep frying

Deep frying is a cooking method in which food is submerged in hot oil or fat. This is normally performed with a deep fryer or chip pan; industrially, a pressure fryer or vacuum fryer may be used....

 is a very high temperature process, it requires a fat with a high smoke point.

The smoke point for an oil varies widely depending on origin and refinement. The smoke point of an oil does tend to increase as free fatty acid content decreases and degree of refinement increases. Heating oil produces free fatty acid and as heating time increases, more free fatty acids are produced, thereby decreasing smoke point. It is one reason not to use the same oil to deep fry more than twice. Intermittent frying has remarkably greater effect on oil deterioration than continuous frying.

Considerably above the temperature of the smoke point is the flash point

Flash point

The flash point of a volatile material is the lowest temperature at which it can vaporize to form an ignitable mixture in air. Measuring a flash point requires an ignition source...

, the point at which the vapors from the oil can first ignite when mixed with air.

The following table presents smoke points of various fats:

Fat	Quality	| Smoke Point
Almond oil		420°F	216°C
Avocado oil Avocado oil Avocado oil is an edible oil pressed from the fruit of the Persea americana . As a food oil, it is used as an ingredient in other dishes, and as a cooking oil. It is also used for lubrication and in cosmetics where it is valued for its regenerative and moisturizing properties.It has an unusually...		520°F	271°C
Butter Butter Butter is a dairy product made by churning fresh or fermented cream or milk. It is generally used as a spread and a condiment, as well as in cooking applications, such as baking, sauce making, and pan frying...		250–300°F	121–149°C
Canola oil	Expeller Press	375-450°F	190-232°C
Canola oil	High Oleic	475°F	246°C
Canola oil	Refined	400°F	204°C
Castor oil Castor oil Castor oil is a vegetable oil obtained from the castor bean . Castor oil is a colorless to very pale yellow liquid with mild or no odor or taste. Its boiling point is and its density is 961 kg/m3...	Refined	392°F	200°C
Coconut oil Coconut oil Coconut oil is an edible oil extracted from the kernel or meat of matured coconuts harvested from the coconut palm . Throughout the tropical world, it has provided the primary source of fat in the diets of millions of people for generations. It has various applications in food, medicine, and industry...	Extra Virgin (Unrefined)	350°F	177°C
Coconut oil	Refined	450°F	232°C
Corn oil Corn oil Corn oil is oil extracted from the germ of corn . Its main use is in cooking, where its high smoke point makes refined corn oil a valuable frying oil. It is also a key ingredient in some margarines. Corn oil is generally less expensive than most other types of vegetable oils. One bushel of corn...	Unrefined	352°F	178°C
Corn oil	Refined	450°F	232°C
Cottonseed oil Cottonseed oil Cottonseed oil is a cooking oil extracted from the seeds of cotton plant of various species, mainly Gossypium hirsutum and Gossypium herbaceum...		420°F	216°C
Flax seed oil	Unrefined	225°F	107°C
Ghee Ghee Ghee is a class of clarified butter that originated in South Asia and is commonly used in South Asian cuisine....  (Indian Clarified Butter)		485°F	252°C
Grapeseed oil		420°F	216°C
Hazelnut oil		430°F	221°C
Hemp oil Hemp oil Hempseed oil is pressed from the seed of the hemp plant irrespective of the strain of cannabis. Cold pressed, unrefined hemp oil is dark to clear light green in color, with a pleasant nutty flavor. The darker the color, the grassier the flavour....		330°F	165°C
Lard Lard Lard is pig fat in both its rendered and unrendered forms. Lard was commonly used in many cuisines as a cooking fat or shortening, or as a spread similar to butter. Its use in contemporary cuisine has diminished because of health concerns posed by its saturated-fat content and its often negative...		370°F	188°C
Macadamia oil Macadamia oil Macadamia oil is the non-volatile oil expressed from the nut meat of the macadamia tree, a native Australian nut...		413°F	210°C
Mustard oil Mustard oil The term mustard oil is used for three different oils that are made from mustard seeds:*A fatty vegetable oil resulting from pressing the seeds,...		489°F	254°C
Olive oil Olive oil Olive oil is an oil obtained from the olive , a traditional tree crop of the Mediterranean Basin. It is commonly used in cooking, cosmetics, pharmaceuticals, and soaps and as a fuel for traditional oil lamps...	Extra virgin	375°F	191°C
Olive oil	Virgin	391°F	199°C
Olive oil	Pomace	460°F	238°C
Olive oil	Extra light	468°F	242°C
Olive oil, high quality (low acidity)	Extra virgin	405°F	207°C
Palm oil Palm oil Palm oil, coconut oil and palm kernel oil are edible plant oils derived from the fruits of palm trees. Palm oil is extracted from the pulp of the fruit of the oil palm Elaeis guineensis; palm kernel oil is derived from the kernel of the oil palm and coconut oil is derived from the kernel of the...	Difractionated	455°F	235°C
Peanut oil Peanut oil Peanut oil is an organic material oil derived from peanuts, noted to have the aroma and taste of its parent legume....	Unrefined	320°F	160°C
Peanut oil	Refined	450°F	232°C
Rice bran oil Rice bran oil Rice bran oil is the oil extracted from the germ and inner husk of rice. It is notable for its very high smoke point of and its mild flavor, making it suitable for high-temperature cooking methods such as stir frying and deep frying...		490°F	254°C
Safflower oil	Unrefined	225°F	107°C
Safflower oil	Semirefined	320°F	160°C
Safflower oil	Refined	510°F	266°C
Sesame oil Sesame oil Sesame oil is an edible vegetable oil derived from sesame seeds. Besides being used as a cooking oil in South India, it is often used as a flavor enhancer in Chinese, Japanese, Korean, and to a lesser extent Southeast Asian cuisine.The oil from the nutrient rich seed is popular in alternative...	Unrefined	350°F	177°C
Sesame oil	Semirefined	450°F	232°C
Soybean oil Soybean oil Soybean oil is a vegetable oil extracted from the seeds of the soybean . It is one of the most widely consumed cooking oils. As a drying oil, processed soybean oil is also used as a base for printing inks and oil paints...	Unrefined	320°F	160°C
Soybean oil	Semirefined	350°F	177°C
Soybean oil	Refined	460°F	238°C
Sunflower oil Sunflower oil Sunflower oil is the non-volatile oil expressed from sunflower seeds. Sunflower oil is commonly used in food as a frying oil, and in cosmetic formulations as an emollient. Sunflower oil was first industrially produced in 1835 in the Russian Empire.- Composition :Sunflower oil is mainly a...	Unrefined	225°F	107°C
Sunflower oil	Semirefined	450°F	232°C
Sunflower oil, high oleic	Unrefined	320°F	160°C
Sunflower oil	Refined	440°F	227°C
Tea seed oil		485°F	252°C
Vegetable shortening		360°F	182°C
Walnut oil Walnut oil Walnut oil is oil extracted from English walnuts . It is about 50% linoleic acid, an essential omega-6 fatty acid. Walnut oil is also a good source of omega-3 fatty acids which are also essential to human nutrition....	Unrefined	320°F	160°C
Walnut oil	Semirefined	400°F	204°C