Safe and Sound – recent publication in Production Engineering Solutions magazine

8th December 2016

 Safe and Sound

Safe and sound 

Developing cutting fluids is a fine balancing act between ensuring performance whilst adhering to strict health and safety regulations. With its rhenus FU 800 coolant, Rhenus Lub has developed a formulation that is free from amines, boric acid and formaldehyde depots. PES reports.

Rhenus Lub is an international system provider of special lubricants, application support and process solutions for metalworking and metal processing. The manufacturer has followed a simple principle with the new composition of rhenus FU 800: consistently avoid potentially hazardous ingredients to achieve a high level of acceptance among machine operators and responsible decision-makers.

Disagreement has prevailed for some time between scientists and manufacturers concerning ingredients and thresholds. For researchers and lawmakers at national and European level, thresholds are liable to change – substances regarded as harmless today may be categorised as posing a risk to health tomorrow. When legislation is tightened, this is often based on more precise measuring techniques or new scientific findings. Users can therefore play it safe if they avoid ingredients that are already at risk of being legislated against sometime in the future from the outset.

What’s not in the product can’t harm you

Users and manufacturers are therefore following a principle that makes sense: substances that are absent from the fluids cannot cause skin irritation, health hazards or any other harm.

Although responsibility for protecting staff always lies with the employer, Rhenus Lub believes it begins with the manufacture of coolants: “We see health and safety today as a preventative measure that we offer our customers, namely users in the metal machining industry,” says Dr Hans-Jürgen Schlindwein, head of laboratory for water miscible coolants at Rhenus Lub.

Compliance with health and safety standards and environmental responsibility is deep rooted in the company, and are ensured by means of quality management and health and safety management systems such as ISO 9001, 14001 and OHSAS 18001.

“We use these standards to formulate our coolants,” explains Dr Schlindwein. “In developing rhenus FU 800 we have consistently avoided all ingredients that are the subject of intense debate at the moment. Our new fluid is therefore the prime example of a modern coolant, combining all beneficial properties into one. It is safe, performs well and has no labelling requirements making it future-proof for the machining sector.”


In formulating rhenus FU 800, researchers at Rhenus Lub avoided amine and boric acid-based additives and also a formaldehyde depot. In addition, a new emulsifier system has also been developed especially for rhenus FU 800, which foams less and has good flushing properties.

Why exclude amine and boric acid-based ingredients? For 25 years, Dr Schlindwein has been actively involved in the development of environmentally friendly fluids with excellent health and safety properties: “The consistent amine-free composition of coolants prevents the build-up of dangerous nitrosamines. Any build-up of carcinogenic compounds from impurities that may be present in the amines is also ruled out through their absence.”

Alongside the amine-free composition, the exclusion of boric acid was also an important step for the research and development team at Rhenus Lub in developing cutting-edge lubricants that are environmentally friendly.

This is because, under the latest EU legislation, boric acid is suspected of being toxic for reproduction and therefore damaging to the human genome: “As a specialist manufacturer of coolants we therefore face a specific challenge”, says Dr Schlindwein. “Boric acid, bonded as boric acid alkanol-amine ester, has long been a key ingredient in the composition of high performance, water miscible coolants.”

Furthermore, the exclusion of the formaldehyde depot is also an example of approaching coolants in a sustainable and responsible manner. Using formaldehyde depots in coolant prevents the growth of bacteria but Formaldehyde, the main component in the formaldehyde depots, is categorised as a 1B carcinogen. Therefore, there is the risk that the formaldehyde depots will be given a similar categorisation.

“But it’s possible to manage without it,” Dr Schlindwein emphasises. “Without there being a statutory requirement to do so — and surpassing the health and safety standards for users – we have found a way to replace these substances with innovative formulations and ingredients. And have done so without raising the pH value.”

Lose the labels

The consistent selection of ingredients means that there are no labelling requirements for rhenus FU 800. This brings a clear benefit to users in the metal machining industry, since labelling requirements can cause real challenges.

Since 1st June 2015, preparations, including coolants, have to be categorised under the GHS/CLP Regulation (Globally Harmonised System, Regulation on Classification, Labelling and Packaging of Substances and Mixtures). The aim of the globally harmonised system is to standardise the protection of human health and the environment, making it more transparent and comparable.

Where there are no labelling requirements, workers feel reassured and companies benefit from a number of concrete operational advantages. If labelling is required, this must be provided and monitored, requiring workers to be trained for the relevant level of hazard. Plant and machinery also has to be modified in some circumstances, at considerable cost.

Dr Schlindwein is convinced that: “It only makes sense for users to work with coolants that have no labelling requirements and pH values that are kind to the skin, particularly in the case of amine-free coolants.”

High performance – contrary to misconceptions

“Many users still believe that for a coolant to perform well, it must have added amines and boric acid,” Dr Schlindwein concludes. “Rhenus FU 800 puts this misconception to rest once and for all. In a range of practical tests, the coolant has proven that it performs at least as well as amine and boric acid-based fluids.”

Testing has also demonstrated that FU 800 can be universally used in demanding machining applications, for example in the aviation industry, where many workpieces have to be milled from a single solid piece of material, ranging from grey cast iron to aluminium through to titanium. In numerous tests conducted at 14 customer premises on 18 machines, the new coolant has yet to reach the limits of its performance.

The full range of Rhenus metalworking fluids, greases and product service are promoted in the UK by Carillon Industrial Services (CIS) which has three sites in Cambridgeshire, Buckinghamshire and Hampshire.

Rhenus Lub

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Safe and sound