used as binders, disintegrants (help the tablet break apart in the digestive system), or flavor enhancers. Some very common diluents in tablets include starch, cellulose derivatives, and magnesium stearate (a lubricant). (See also Excipient.) Diluents are also used in vaccines such as MMR to reconstitute the vaccine after storage. Breathing gas In underwater diving a diluent gas is generally used to reduce the oxygen fraction of the breathing gas to a non-toxic level appropriate to the ambient pressure at which it is to be breathed. Diluent gases for this use are metabolically inert and non-toxic, but may have some level of narcotic effect at high partial pressure. The commonly used diluents for breathing gases are nitrogen, provided in the form of air, and helium, provided as heliox, or both nitrogen and helium together as trimix. The diluent used in scuba rebreathers contains enough oxygen to support life as it is also used as a bailout gas. Helium is also useful as a breathing gas diluent to reduce work of breathing of gases, both at high ambient pressures, and for medical purposes, but it is an expensive gas, which limits its utility. Drugs The 1985 diethylene glycol wine scandal was an incident in which several Austrian wineries illegally adulterated their wines using the toxic substance diethylene glycol (a primary ingredient in some brands of antifreeze) to make the wines appear sweeter and more full-bodied in the style of late harvest wines. References Solutions Solvents de:Streckmittel