Terne, an alloy of tin and lead, serves as the metal plating on some oil filters. The lead concentration found in unused terne-plated oil filters can render the oil filter a hazardous waste. Typically, light duty vehicle operations such as automobiles and light duty trucks use non-terne plated filters. If the filter exceeds the regulatory standard of 5 ppm lead, then the filter must be managed as hazardous waste. If oil is kept free from dirt, water and metal particle contamination, and if the additive content is maintained at a high enough level, the oil will retain its lubricating qualities longer.
Most laboratories also give instructions about further treatment of the engine and the oil.
There are also field test devices which provide basic information about oil condition but are not as detailed or thorough as laboratory analysis. These field devices give results in less than 5 minutes and are easy to use. Ultrafiltration - Ultrafiltration units continually filter oil to keep it free of water, dirt, carbon and other particulate buildup. Engines are normally equipped with an oil filter which removes particles between 10 and 25 microns in size. An additional ultrafilter can capture particulate contamination down to 0.5 microns.