Frequently Asked Questions:

1. Why do Metalworking Fluids (MWF) stink on a Monday morning after a machine has been off for a weekend?

The MWF solution is mostly made up of water. The water contains bacteria and fungi. When the machine is switched off the MWF stops circulating and the residual oil from the machine’s slides, gearbox etc forms a layer on top of the fluid. The fluid is now anoxygenic and anaerobic bacteria digest the residual oil and produce hydrogen disulphide (stink bomb gas) and sulphuric acid. Bacteria double their number over a short period thus the bacterial growth is exponential. Once the machine is switched on, the fluid circulates releasing all the hydrogen disulfides into the atmosphere…hence the smell.

2. Is there anything like an environmentally friendly MWF?

Any fluid that contains oil in water with additives is deemed hazardous and therefore cannot be dumped into a municipal system. Even if the oil utilized in the product is a natural product it is still classified as hazardous.

3. What are the most important tests to conduct on MWF?

The concentration of the fluid is the most important test to conduct. The concentration specification is the primary tool that can be used to determine if the fluid is in a good condition. Another important test is the pH of the fluid. This is important as the correct pH ensures that the fluid is not corrosive and is also free from harmful bacteria.