What Are Oil Mist & Oil Smoke?

Oil mist and oil smoke is generated from a number of various manufacturing operations. Before we can take the correct measures to overcome the risks and harm that these substances cause, we need to know specifically what oil mist and oil smoke really are.

In the manufacturing industry, oil mist arises especially during metal-cutting machining, which is a comprehensive term for turning, milling, grinding and boring, etc. Oil mist arises when oil or water mixed with concentrated cutting fluid, so-called emulsion, is used for cooling, lubricating or chip removal.

With high speed and pressure, the oil drops get very small (‹1 µm) and the amount of oil in the air is often high. In such operations, oil smoke occurs in a larger scale. 

As machining operations are carried out, these fluids are emitted in the form of aerosols and smoke to the surrounding air. It is, of course, unhealthy to breathe these substances.

A typical metal cutting application (lathe or mill) being cooled by emulsion will produce an oil mist
consisting of:
► Hydraulic oil – leakage from hydraulic pipes on the machine
► Lubricating oil – leakage from the slide ways and lube points on the machine
► Metal particulates, slivers, sludge – drained back into the sump
► Additives – used to try to kill the bacteria growing in the sump
► Carbide – from the metal cutting tools
► Exotic Platings – from the platings applied to the cutting tools to prolong tool life
► Heat – from the cutting action; typically 20 – 25 Degree
► Water – water is a good substance for cultivating bacteria, especially contaminated water. So, oil mist is more than just one chemical and in fact comprises of a cocktail of chemicals and additives used to kill the bacteria. The dying bacteria also create harmful endotoxins adding further danger to the inhalation of oil mist.