Information on substances
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Information on substances |
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Quaternary ammonium compounds (rev. 2006)
Altogether there are some 350 quaternary ammonium compounds in products reported to the Products Register. The only thing they all have in common is that they contain a nitrogen atom which bonds with four other atoms and in doing so becomes positively charged. The molecule becomes kationic. The four “arms” of the quaternary compound can look very different, and the molecules can be completely different both physiologically, biologically and functionally speaking. On the other hand, the counter-ion, the negative chloride or methylsulphate ion included in the compound, seems in most cases to make little difference to the properties of the compound. In many quaternary ammonium compounds, the charged nitrogen is embedded in a large, organic molecule which can contain both several aromatic structures and other hetero-atoms. If so these are often pigments. One quaternary ammonium compound with which many are acquainted is Bitrex, the bittering compound which is often added to industrial alcohol to make it undrinkable. Most often when we speak about quaternary ammonium compounds, we mean substances which have been made surfactant by giving different fat/water solubility to different parts of the molecule. This is done by linking up one or more long carbon chains, a common length being up to 20 carbon atoms per chain. Most often these long carbon chains come from natural fats such as tallow or coconut oil. Water solubility and degradability of these and other side groups can then be moderated by introducing hydroxyl groups and acid bridges (ethoxilition, for example). The intention is for the positively charged nitrogen part of the molecule to attach itself to surfaces (which for the most part are negatively charged) and there, depending on the arms = change connected, act as plasticiser, antistat agent, biocide, corrosion protection in relation to a surrounding medium or otherwise change the properties of the surface. Several types of quaternary ammonium compound are manufactured in Sweden. Since they are solid substances, sometimes of low solubility, the raw material is sold in solution form. They are used in detergents and rinsing agents and for disinfection. Quaternary ammonium compounds are also used in paints and to modify the properties of paper, and they often have reactive side-groups or contain surface-active clay. Since they are added to chemical products in small quantities, these substances are not generally judged to be sufficiently dangerous for health always to be included in company reports to the Products Register. As a result, the quantities shown in products could be lower than those actually used.
Contact person: Margareta Östman,
Tel +468 519 411 62
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