Smelling salts, also known as ammonia inhalants, spirit of hartshorn or sal volatile, are chemical compounds used as stimulants to restore consciousness after fainting. [1]
The usual active compound is ammonium carbonate—a colorless-to-white, crystalline solid ((NH4)2CO3). [1] Because most modern solutions are mixed with water, they should properly be called "aromatic spirits of ammonia". [1] Modern solutions may also contain other products to perfume or act in conjunction with the ammonia, such as lavender oil or eucalyptus oil. [2]
Historically, smelling salts have been used on people feeling faint, [3] [4] [5] or who have fainted. They are usually administered by others but may be self-administered.
Smelling salts are often used on athletes who have been dazed or knocked unconscious to restore consciousness and mental alertness. [1] Smelling salts are now banned in most boxing competitions because of the concern that their effect could mask a more serious injury. [6]
They are also used as a form of stimulant in athletic competitions (such as powerlifting, strong man, rugby and ice hockey) to "wake up" competitors to perform better. [1] [7] In 2005, Michael Strahan estimated that 70–80% of National Football League players were using smelling salts as stimulants. [8]
Smelling salts have been used since Roman times and are mentioned in the writings of Pliny as Hammoniacus sal. [1] Evidence exists of use in the 13th century by alchemists as sal ammoniac. [1] In the 14th-century "The Canon's Yeoman's Tale", one of Chaucer's The Canterbury Tales , an alchemist purports to use sal armonyak. [9] In the 17th century, the distillation of an ammonia solution from shavings of harts' (deer) horns and hooves led to the alternative name for smelling salts as spirit or salt of hartshorn. [1]
They were widely used in Victorian Britain to revive fainting women, and in some areas, constables would carry a container of them for that purpose. [10] At that time, smelling salts were commonly dissolved with perfume in vinegar or alcohol and soaked onto a sponge, which was then carried on the person in a decorative container called a vinaigrette. [11] [12] The sal volatile appears several times in Dickens' novel Nicholas Nickleby .
The use of smelling salts was widely recommended during the Second World War, with all workplaces advised by the British Red Cross and St. John Ambulance to keep smelling salts in their first aid boxes. [13]
Solid ammonium carbonate and ammonium bicarbonate salts partly dissociate to form NH
3 , CO
2 and H
2O vapour as follows:
The smelling salts release ammonia (NH
3) gas, which triggers an inhalation reflex. It causes the muscles that control breathing to work faster by irritating the mucous membranes of the nose and lungs. [7]
Fainting can be caused by excessive parasympathetic and vagal activity that slows the heart and decreases perfusion of the brain. [14] The sympathetic irritant effect is exploited to counteract these vagal parasympathetic effects and thereby reverse the faint. [15]
Exposure to ammonia gas in large concentrations for prolonged periods is toxic and can be fatal. [1] [5] If a high concentration of ammonia is inhaled too close to the nostril, it might burn the nasal or oral mucosa. The suggested distance is 10–15 centimetres (4–6 in). [1]
The use of ammonia smelling salts to revive people injured during sport is not recommended because it may inhibit or delay a proper and thorough neurological assessment by a healthcare professional, [1] such as after concussions when hospitalization may be advisable, and some governing bodies recommend specifically against it. [16] The irritant nature of smelling salts means that they can exacerbate any pre-existing cervical spine injury by causing reflex withdrawal away from them, although this has been found to be a result of holding the smelling salts closer to the nose than recommended. [1]
Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the formula NH3. A stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pungent smell. Biologically, it is a common nitrogenous waste, and it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to fertilisers. Around 70% of ammonia produced industrially is used to make fertilisers in various forms and composition, such as urea and diammonium phosphate. Ammonia in pure form is also applied directly into the soil.
Ammonium is a modified form of ammonia that has an extra hydrogen atom. It is a positively charged (cationic) molecular ion with the chemical formula NH+4 or [NH4]+. It is formed by the addition of a proton to ammonia. Ammonium is also a general name for positively charged (protonated) substituted amines and quaternary ammonium cations, where one or more hydrogen atoms are replaced by organic or other groups. Not only is ammonium a source of nitrogen and a key metabolite for many living organisms, but it is an integral part of the global nitrogen cycle. As such, human impact in recent years could have an effect on the biological communities that depend on it.
In chemistry, there are three definitions in common use of the word "base": Arrhenius bases, Brønsted bases, and Lewis bases. All definitions agree that bases are substances that react with acids, as originally proposed by G.-F. Rouelle in the mid-18th century.
Carbonation is the chemical reaction of carbon dioxide to give carbonates, bicarbonates, and carbonic acid. In chemistry, the term is sometimes used in place of carboxylation, which refers to the formation of carboxylic acids.
Salammoniac, also sal ammoniac or salmiac, is a rare naturally occurring mineral composed of ammonium chloride, NH4Cl. It forms colorless, white, or yellow-brown crystals in the isometric-hexoctahedral class. It has very poor cleavage and is brittle to conchoidal fracture. It is quite soft, with a Mohs hardness of 1.5 to 2, and it has a low specific gravity of 1.5. It is water-soluble. Salammoniac is also the archaic name for the chemical compound ammonium chloride.
Hydroxylamine is an inorganic compound with the chemical formula NH2OH. The compound is in a form of a white hygroscopic crystals. Hydroxylamine is almost always provided and used as an aqueous solution. It is consumed almost exclusively to produce Nylon-6. The oxidation of NH3 to hydroxylamine is a step in biological nitrification.
Ammonium bicarbonate is an inorganic compound with formula (NH4)HCO3. The compound has many names, reflecting its long history. Chemically speaking, it is the bicarbonate salt of the ammonium ion. It is a colourless solid that degrades readily to carbon dioxide, water and ammonia.
Ammonium carbonate is a chemical compound with the chemical formula [NH4]2CO3. It is an ammonium salt of carbonic acid. It is composed of ammonium cations [NH4]+ and carbonate anions CO2−3. Since ammonium carbonate readily degrades to gaseous ammonia and carbon dioxide upon heating, it is used as a leavening agent and also as smelling salt. It is also known as baker's ammonia and is a predecessor to the more modern leavening agents baking soda and baking powder. It is a component of what was formerly known as sal volatile and salt of hartshorn, and produces a pungent smell when baked. It comes in the form of a white powder or block, with a molar mass of 96.09 g/mol and a density of 1.50 g/cm3. It is a strong electrolyte.
Ammonium sulfate (American English and international scientific usage; ammonium sulphate in British English); (NH4)2SO4, is an inorganic salt with a number of commercial uses. The most common use is as a soil fertilizer. It contains 21% nitrogen and 24% sulfur.
Acid salts are a class of salts that produce an acidic solution after being dissolved in a solvent. Its formation as a substance has a greater electrical conductivity than that of the pure solvent. An acidic solution formed by acid salt is made during partial neutralization of diprotic or polyprotic acids. A half-neutralization occurs due to the remaining of replaceable hydrogen atoms from the partial dissociation of weak acids that have not been reacted with hydroxide ions to create water molecules.
Ammonium nitrite is a chemical compound with the chemical formula [NH4]NO2. It is the ammonium salt of nitrous acid. It is composed of ammonium cations [NH4]+ and nitrite anions NO−2. It is not used in pure isolated form since it is highly unstable and decomposes into water and nitrogen, even at room temperature.
Selective catalytic reduction (SCR) means converting nitrogen oxides, also referred to as NO
x with the aid of a catalyst into diatomic nitrogen, and water. A reductant, typically anhydrous ammonia, aqueous ammonia, or a urea solution, is added to a stream of flue or exhaust gas and is reacted onto a catalyst. As the reaction drives toward completion, nitrogen, and carbon dioxide, in the case of urea use, are produced.
In chemistry, hexol is a cation with formula {[Co(NH3)4(OH)2]3Co}6+ — a coordination complex consisting of four cobalt cations in oxidation state +3, twelve ammonia molecules NH
3, and six hydroxy anions HO−
, with a net charge of +6. The hydroxy groups act as bridges between the central cobalt atom and the other three, which carry the ammonia ligands.
The Kjeldahl method or Kjeldahl digestion (Danish pronunciation:[ˈkʰelˌtɛˀl]) in analytical chemistry is a method for the quantitative determination of a sample's organic nitrogen plus ammonia/ammonium. (NH3/NH4+). Without modification, other forms of inorganic nitrogen, for instance nitrate, are not included in this measurement. Using an empirical relation between Kjeldahl nitrogen and protein, it is an important method for indirectly quantifying protein content of a sample. This method was developed by Johan Kjeldahl in 1883.
Ammonium paratungstate (or APT) is a white crystalline salt with the chemical formula (NH4)10(H2W12O42)·4H2O. It is described as "the most important raw material for all other tungsten products."
Barium chlorate, Ba(ClO3)2, is the barium salt of chloric acid. It is a white crystalline solid, and like all soluble barium compounds, irritant and toxic. It is sometimes used in pyrotechnics to produce a green color. It also finds use in the production of chloric acid.
Ammonium dinitramide (ADN) is an inorganic compound with the chemical formula [NH4][N(NO2)2]. It is the ammonium salt of dinitraminic acid HN(NO2)2. It consists of ammonium cations [NH4]+ and dinitramide anions −N(NO2)2. ADN decomposes under heat to leave only nitrogen, oxygen, and water.
The deliming operation in leather processing is a drum/paddle or pit based operation where two main objectives are met:
Ammonium cyanide is an unstable inorganic compound with the formula NH4CN.
Ammonium carbamate is a chemical compound with the formula [NH4][H2NCO2] consisting of ammonium cation NH+4 and carbamate anion NH2COO−. It is a white solid that is extremely soluble in water, less so in alcohol. Ammonium carbamate can be formed by the reaction of ammonia NH3 with carbon dioxide CO2, and will slowly decompose to those gases at ordinary temperatures and pressures. It is an intermediate in the industrial synthesis of urea (NH2)2CO, an important fertilizer.