Risk analysis of microbiology in coolants

Biocide free vs. biocide-containing coolants

Due to market requirements as well as against the background of the CLP Regulation, REACH and biocide regulations, over the last years, Oemeta expanded its portfolio with biocide-free products. By using biocide-free cooling lubricants, current requirements concerning occupational safety should be considered. 

Within the context of occupational safety, the hazard potential of germ growth has to be evaluated when carrying out a hazard analysis at the customer site. (See DGUV 209-051 as well as Section 3, Paragraph (1) BioStoffV; regulation of German Social Accident Insurance).

In relation to biocide-free cooling lubricants, the following question might occur:

Compared to biocide-containing cooling lubricants, is there an increased potential in the development of pathogenic germs, which belong to risk groups 3 and 4 according to ‘BioStoffV’, in biocide-free cooling lubricants?

In order to answer this question, in cooperation with the renowned Institute for Hospital and Environment Hygiene of the University Medical Center in Kiel (UKSH), Germany, a comparative study of biocide-free and biocide-containing cooling lubricants was executed.
Against the background of a hazard analysis, the conclusion of the final report is as follows: 

Micro-organisms, which belong to risk groups 1 and 2 according to TRBA 466, were detected in biocide-containing as well as in biocide-free cooling lubricants [...]. The detected micro-organisms are environmental flora, mainly so-called ‘humidity loving bacteria’, which are often detected in water-bearing systems. […]

The report states, that regarding the risk groups of the identified micro-organisms, there is no higher hazard potential when using biocide-free cooling lubricants compared to biocide-containing cooling lubricants. In both cases, it is ubiquitous (widely spread) environmental flora with so-called ‘humidity loving bacteria’, which can be assigned to risk groups 1 and 2. Thus, also for biocide-free cooling lubricants the following is indiscriminately valid: Activities with microbially colonized water-miscible cooling lubricants are non-targeted activities with biomaterials without assignment to protection levels (DGUV 209-051).

This implies for the user, that biocide-free cooling lubricants do not provide any disadvantages regarding the hazard of germ growth but improve occupational safety due to their human compatibility.