Metalworking

Citation

Margaroni, D. (1998), "Metalworking", Industrial Lubrication and Tribology, Vol. 50 No. 4. https://doi.org/10.1108/ilt.1998.01850daa.001

Metalworking

Metalworking

Keywords: Health and Safety, Lubricants, Metalworking

Although the term "metalworking" encompasses both metal cutting and metal forming operations, the metal cutting fluid market predominates to such an extent that most of the interest and activity in the field of metalworking is directed towards metal cutting activities.

Metalworking fluids (MWFs) are notable in the field of application of lubricants in that their use probably involves greater potential for operator contact than with any other lubricant in the industrial environment. It is not surprising, therefore, that Health and Safety issues are at least of equal importance to performance aspects when the application of such products is considered. Also, environmental matters feature strongly, since the disposal of metalworking fluids, particularly those of the watermix variety, is an important issue.

In addition to any health hazards associated with the metalworking fluid composition, other hazards can arise from contamination during use, either by microbial contamination of watermix fluids, which provide a rich breeding ground for an assortment of microorganisms, or from the workpiece metal fines which are present in the MWF. Metals such as cobalt, nickel and chromium are commonly present during machining operations, and significant quantities may be leached into the MWF. In addition, sensitisers such as the biocides formaldehyde and formaldehyde release agents, isothiazolines, morpholines, ethylenediamine, etc., are commonly found in MWFs.

In the UK , the Health and Safety Executive have played an extremely active role in the education process in the correct handling of MWFs, and the incidence of complaints among users has fallen over the years due to a number of factors, including "safer" formulations, improved working conditions and better understanding of the hazards by the operator. It is evident from the descriptive literature now supplied by virtually all product manufacturers that much emphasis is placed upon the absence of certain components, such as amines, nitrites, phenols, chlorine, etc.

Nevertheless, pressure for improved controls continues to mount, and probably nowhere more so than in the USA, where the powerful American Automobiles Manufacturers Association has been campaigning for a ten-fold reduction in allowable oil mist concentrations, i.e. from 5mg/m³ to 0.5mg./m³. The US Environmental Protection Agency (EPA) had already commented on the advisability and need for a Product Stewardship Programme, and this initiative has now been taken up by the Independent Lubricant Manufacturers Association (ILMA). A Metalworking Fluid Product Stewardship Group (MWFPSG) within ILMA has now been set up, with the following objectives:

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  Develop MWF "best practices" management guidelines.

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  Peer-review and publish existing participating company subchronic health effects data.

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  Conduct an extensive literature search of MWF components' health effects information via electronic databases.

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  Disseminate component and formulated generic product dermal and inhalation-effects product testing information.

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  Provide partial support for an already-begun respiratory health-effects study of apprentice machinists; and develop information on toxicological properties of in-use MWFs, through participation in a National Centre for Manufacturing Sciences-sponsored project.

It is anticipated that, following the above course of action, objective evidence will be obtained which will result in the establishment of cost-effective and scientifically-justifiable MWF exposure limits, rather than to adopt the somewhat arbitrary standards which are being suggested without any proper scientific basis at the moment. What is known is that the lowering of the limit to 0.5 mg/m³ will place an enormous financial burden on industry, which may not be justified if there are no practical benefits.

The MWFPSG is a non-profit group and is open to any ILMA member, who all contribute on a sliding scale towards the costs based on MWF gallonage or MWF sales to formulators, depending on members status. In addition to receiving privileged information, participating members receive a number of other benefits.

It has already been suggested by the British Lubricants Federation (BLF) that the UK could benefit from the establishment of such a group, but the problem at the moment is a lack of funding. The enormity of scale of the US MWF market compared with that of the UK means that the comparatively large sums involved in setting-up and maintaining such a group would be met by a much smaller percentage of the turnover of participants. In spite of the useful work already accomplished by the HSE, any possible funding from the HSE is limited to specific and clearly-identified problem areas. However, in comparison with the rather confrontational situation which exists in the USA regarding the creation and imposition of health and safety legislation, the UK is fortunate in that a more measured approach, involving consultation by government bodies with all interested parties, is more usually the case. The UK also favours the conducting of proper risk benefit analyses before implementing outright bans on substances thought to be potentially hazardous, as in the case of short-chain chlorinated paraffins. In this situation, it may well be that the need for product stewardship as a purely defensive measure by industry is not as pronounced as in the USA. However, there is a continuing need to develop our existing knowledge on the health and environmental aspects of all substances with a potential to cause harm, and such product stewardship programmes would seem to be the way forward. In an effort to maintain the momentum, the BLF has approached the Union of European Independent Lubricants Manufacturers (UEIL) with the suggestion that the funding problem could possibly be overcome if the stewardship group was organised on a European basis rather than a UK-only basis.

Also, as a result of the general health, safety and environmental concerns, more attention is being focused on the need for the use of conventional metalworking fluids. A number of reports, one of which appears in this issue, identify that the actual volume requirement for a metalworking fluid is very much less than that which is used as a matter of course in general machining operations. It could well be that developments in application technique will considerably reduce the quantities in use, with obvious environmental, and possible health and safety, benefits. Also, increased attention is being paid to the use of dry machining, without the use of any lubricant whatsoever, particularly in the USA and also in Germany. The significance of this development and the potential scope of practical applicability in the metalworking industry remain to be seen.

David MargaroniEditor