Apiezon Grease, Type L relative to the other Apiezon greases, contains lower molecular weight wax and is reported to contain absolutely no additives whatsoever. The ultimate vapor pressure is 2x10-11 torr at 20° C and the best of all the Apiezon greases. . The grease can be used in gas liquid chromatography applications and also, the ground glass joints of any vacuum system. The melting point is quite low, and Apiezon grease, type L is not recommended for use at temperatures exceeding 30° C, so this is strictly for room temperature applications. One would not want to use this grease near the filament housing (which gets quite hot) in any SEM or TEM since there would be quite substantial off-gassing of the low melting point product. And remember, this grease is completely hydrocarbon and is totally free of any silicones or halogens. Apiezon L is highly versatile and can be applied in a number of different ways.

It can be dissolved in a variety of organic solvents.
One advantage of Apiezon L over certain other greases, such as silicon greases, is that it can be dissolved in a number of different solvent liquids for a more highly controlled deposition on a surface. Hexane: Apiezon L will dissolve in hexane to 11% weight/weight. When heated to 50°C , the solution becomes cloudy. d-limonene: This might be a better solvent, it is extracted from orange peel and can be purchased from the Florida Chemical Company, Inc. This leaves a gel at room temperature and a concentration of 11%weight/weight. When heated to 50°C, the solution becomes clear which indicates that although the grease is molten at this temperature, it is still compatible with the solvent. Lower temperatures might be possible but we have data only for 50°C. Toluene: Behaves similarly to d-limonene but remains slightly cloudy at 50°C.

Apiezon L grease can also be used to protect electrical contacts. Apiezon L grease can also be used to protect electrical contacts. The grease itself is of course an insulator, however, the grease film on a contact is so thin at the actual point of contact that it just does not interfere with the passage of electrical current except for the smallest of voltages. To further clarify this point, Apiezon L has an electrical strength of 720 volts per mil (0.001"/25 µm). In a metal to metal contact the film of grease would be only of the order of 0.00001"/0.25 µm) or less, giving an electrical strength of only 7 volts. For contacts operating at high temperatures, use Apiezon T.

Trace element analysis: Apiezon L grease is known for its low levels of trace elements.