Apiezon Grease L is a petrolatum hydrocarbon grease containing no additives. It has excellent vapor pressure capabilities, and is recommended for high vacuum use. It is widely used in gas-liquid chromatography, and may be used on all ground joins in a vacuum system where it is essential to have a grease with good lubricating properties and a low vapor pressure. It melts at 47°C and should not be used where temperatures at joints are likely to be above 30°C.