New biocide stable corrosion inhibitors


Concerns over the use of biocide that either contains or generates formaldehyde in cutting fluids have led to new EU legislation. Metalworking fluids and coolants manufacturers will face new formulary challenges in 2018. The Biocidal Products Regulation will require authorisation of any commercially available biocidal products (BP).

Metalworking fluids and coolants manufacturers use biocides to reduce souring of water based coolants / soluble oils by micro organisms. Frequently, slide way oil mixes into the coolant, providing a source of sulphur nutrient for the microbes.

Many producers expect that the new legislation will restrict the use of certain types of BPs. Some BPs that they currently use will become unavailable. Moreover, many formulators expect that they will need to remove BPs that either contain or generate formaldehyde. They will need to replace with non-formaldehyde alternative products.


A soluble oil metalworking fluid typically contains a balanced mixture of water, dispersing agents, mineral oil, EP/Antiwear agents, corrosion inhibitors, metal deactivators and biocides. However, if a formulator changes one component, this change can alter the stability of other components in the fluid.

>Brad-Chem have developed corrosion inhibitors that have better stability in metalworking fluids formulated with non-formaldehyde biocides. Brad-Chem DP 3717 is a water soluble corrosion inhibitor for iron, steel, aluminium and ferrous metals with improved stability in metalworking fluids / coolants that are formulated with non-formaldehyde biocidal products.

The acid components that constituted the now discontinued product Corfree M1 form the basis of the new products. This new development means that manufacturers of metalworking fluids, soluble oils, and coolants can future-proof their metalworking fluids.

The new biocide stable Brad-Chem corrosion inhibitors not only replace both Corfree M1 and the bases that are typically used to neutralise it. Additionally, we can also work with customers to produce bespoke versions for specific applications if the annual volume is sufficient.

For further information, contact us and speak to our technical team.