Exhaust and filtration of metal working fluids emissions on machine tools

Project No. BGIA 3093


completed 05/2006


With a small number of exceptions, the machining of metal and glass involves the use of metal working fluids. According to estimates, 4.5 million employees are exposed to cooling lubricants in Germany in 200,000 businesses, the majority of them small and medium-sized enterprises.

Metal working fluids contain a wide variety of component substances, the composition of which changes during the lubricants' use, leading to the formation of new substances. Foreign substances are also added. The fluids are essentially used on machine tools, where they cause emissions which may lead to disorders of the respiratory tract. Under certain conditions, carcinogenic and toxic substances may be released. Despite diverse attempts to find substitutes for them, their use remains unavoidable in the majority of cases.

In the course of the project, studies were to be conducted into the metal working fluids emissions arising on machine tools. The results were to be used for improvements to collection facilities for cooling lubricant emissions and to their filtration.


A test section was first developed with the aid of which the emission rates from various machine tools were then determined. Preliminary measurements were also conducted of the degree of filtration achieved by various filters. A more important objective was however to obtain information for the further development of a test bench for metal working fluid filters. In addition, the results were to serve as comparison data for a numeric flow simulation intended for use at a later stage for parameter studies.


The comprehensive measured data and the experience gained during studies in the machine tool laboratory are to be used for setting up of a test bench for metal working fluid filters at the BG Institute for Occupational Safety and Health (BGIA). For validation of the results, simulation analyses must be performed in order to permit assessment of the effect of displacing the degree of fractional filtration at variable liquid/vapour equilibria in the filter. This would also have a bearing upon the results of the tests on the test bench. The studies are to be conducted in a follow-on project.

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Financed by:
  • Hauptverband der gewerblichen Berufsgenossenschaften (HVBG)
  • VMBG - Vereinigung der Metall-Berufsgenossenschaften
Research institution(s):
  • Berufsgenossenschaftliches Institut für Arbeitsschutz - BGIA
  • Werkzeugmaschinenlabor der RWTH
  • Aachen
  • Universität Stuttgart
  • Hersteller von Werkzeugmaschinen
  • Hersteller von Abscheidern
  • Allgemeine Unfallversicherungsanstalt (AUVA)
  • Wien

metal working

Type of hazard:

Gefahrstoffe, Biologische Arbeitsstoffe, Mechanische Gefährdungen


Arbeitsumwelt (Belastungen, Gefährdungen, Expositionen, Risiken), Chemische Arbeitsstoffe, Klein- und Mittelbetriebe

Description, key words:

metal working fluids emissions, exhaust, filtration, air recirculation, machine tool enclosures, fire and explosion protection, cooling lubricants