Hazardous components of metalworking fluids

Citation

Margaroni, D. and Walker, M.J. (1998), "Hazardous components of metalworking fluids", Industrial Lubrication and Tribology, Vol. 50 No. 4. https://doi.org/10.1108/ilt.1998.01850dab.002

Hazardous components of metalworking fluids

Hazardous components of metalworking fluids

Keywords: Biocides, Carcinogenicity, Chemicals, Health and Safety, Metalworking fluids, Regulations

Recent developments highlighting health and environmental concerns over certain components which have been historically used in metalworking fluids have increased pressure for their removal.

This article summarises the current situation with regard to a number of these components.

Diethanolamine and diethanolamine derivatives

In the USA, the National Toxicology Program (NTP) Board of Scientific Counsellors met recently to discuss their peer review of draft reports detailing the findings of chronic bioassays of diethanolamine (DEA) and derivatives involving two-year skin-painting tests on rats and mice. The bioassay results were reported as follows.

Diethanolamine

Clear evidence of carcinogenic activity for male and female mice, but no evidence of carcinogenic activity for male and female rats.

Coconut oil acid diethanolamine condensate

Clear evidence of carcinogenic activity for male and female mice, equivocal evidence of carcinogenic activity for female rats, and no evidence of carcinogenic activity for male rats.

Lauric acid diethanolamine condensate

Some evidence of carcinogenic activity for female mice, but no evidence of carcinogenic activity for male mice and male and female rats.

Oleic acid diethanolamine condensate

No evidence of carcinogenic activity for male and female mice or male and female rats.

However, these finding have been vigorously opposed by the Chemical Manufacturers Association (CMA) who contend that the experimental design of the study was flawed. The CMA argues that:

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  The mice used in this study had an extremely high background incidence of liver tumours, i.e. some 66-78 per cent.

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  Analyses of the control feed used in the study showed high levels of bacteria, which could have resulted in increased nitrite levels. These could in turn contribute to the formation of nitrosamines, which are known to be carcinogenic.

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  Other properties of the study animals, including early mortality and increased obesity, could have contributed to the positive results of carcinogenic activity.

Other points which have been raised include concerns over the use of ethanol in the NTP study to prepare solutions of the DEA. Ethanol has been identified as a tumour risk factor, and could increase the likelihood of cancer in experimental animals. Also, the dermal site of exposure was not covered over, therefore the animal could ingest the DEA/ethanol directly, increasing the possibility of nitrosamine formation. The NTP reports do indicate that the carcinogenic activity of the DEA derivatives could well be owing to the presence of free DEA as a contaminant.

A number of other mutagenicity and genotoxicity studies on DEA in a variety of test systems have all been consistently negative.

It would require a much fuller analysis of all existing test data to conclude that DEA poses any sort of cancer risk to humans and, on the basis of the current evidence, it would appear that there is need for further work before the hazardous potential of DEA can be properly quantified.

However, DEA has been under regulatory scrutiny since evidence was obtained over 20 years ago of the presence of nitrosamines, formed from the reaction of amines with sodium nitrite, in metalworking fluids. It is likely that this combination of substances poses a greater health risk than that of the DEA itself, since the majority of nitrosamines are known to have carcinogenic activity.

David MargaroniEditor

Sodium nitrite, alkylated phenols and cresylic acid

These ingredients have been targeted in a recent initiative by the Metalworking Fluids Group of the British Lubricants Federation (BLF) requesting voluntary withdrawal from use by their member companies. They maintain that the UK is lagging behind in comparison with the USA and many of our European colleagues in phasing-out substances which are known to be hazardous. Continued use of these substances is also at odds with the requirements of the Control of Substances Hazardous to Health (COSHH) regulations, which requires substitution or removal of a hazardous ingredient as the primary control measure. Users of products containing these components are not complying with the requirements of the COSHH regulations, since alternatives are available, albeit at a cost and/or performance penalty.

Sodium nitrite is a systemic poison by ingestion, and may also be absorbed through the skin. Formulations containing from 1 to 5 per cent are classified as harmful, those containing 5 per cent or more are classified as toxic (assuming that there are no other harmful or toxic ingredients in the formulation). In addition to the potential dangers to human health, sodium nitrite is harmful to aquatic life, even at low concentrations. In addition, nitrites can be converted to nitrates, which may be detrimental in some water supplies. The potential for nitrosamine formation in the presence of amines has been recognised for some time in the metalworking industry, which is of concern since over 80 per cent of such nitrosamines have been shown to be carcinogenic.

Alkylated phenols and cresylic acid have been used for many years as metalworking fluid bases in watermix fluids, since they promote readily formed and stable emulsions and resist microbial contamination. However, again they are systemic poisons which can be readily absorbed through the skin, even at high dilution. The Occupational Exposure Limits for these ingredients are 5 ppm (vapour), 19 mg/m³ (mist) and 5 ppm (vapour), 22 mg/m³ (mist) respectively. Products containing these ingredients are classified as harmful and irritant at inclusion levels of up to 5 per cent, and as toxic and corrosive at inclusion levels of 5 per cent or more, assuming that there are no other toxic or corrosive components in the product. Again, these chemicals are toxic to aquatic life, with alkylated phenol being toxic to fish at levels as low as 1ppm.

The BLF is strongly urging its members to voluntarily discontinue the use of these ingredients, primarily for the health and environmental benefits. However, they are also of the belief that the legislative and regulatory authorities would be more willing to consult and debate with an industry that is not merely showing a concern for health safety and environmental matters, but is actively demonstrating a capacity for responsible self-regulation. Any further information on this issue can be obtained from: Robert Stubbs, Technical Director of Polartech Ltd. and Chairman of the BLF Metalworking Fluids Committee on Tel: 0161 876 5673.

Chlorinated paraffins

Current regulatory status of chlorinated paraffins

Oslo and Paris Conventions for the Prevention of Marine Pollution

PARCOM decided (Decision 95/1) to phase out all applications of short chain (C10-C13) chlorinated paraffins by the end of 1999, except for uses in rubber conveyor belting and dam sealants, where the phase-out date was deferred until the end of 2004.

The UK has not accepted this decision, as they believe that the action was premature while the EU Risk Assessment was underway. Because of this, UK industry is not obliged to comply with the PARCOM decision.

European Commission Regulation 793/93 ­ Evaluation and Control of the Risk of Existing Chemical Substances

Short chain (C₁₀-C₁₃) chlorinated paraffins were studied on the first priority list under this regulation, and the conclusions of the risk assessment are to be published in the Official Journal in early 1998. The only areas of concern, where risk reduction measures will be needed, are in the use of metal working fluids, and leather fat liquors. DG III of the European Commission is currently considering appropriate measures. The impact of these are as yet unknown.

The risk assessment has confirmed the provisional classification by producers, of short chain chlorinated paraffins being dangerous for the environment carrying the risk phrase R50/53.

There is noticeable inconsistency between the EU risk assessment conclusion and the PARCOM decision. EU are requesting a revision of PARCOM 95/1.

United Nations Economic Commission for Europe (UN-ECE)

Protocol on persistent organic pollutants (POPs). A protocol on persistent organic pollutants has been finalised under the long-range transboundary air pollution activities, culminating in an agreed list of substances which will require either elimination or restrictions on use. Processes and criteria for additional substances are included in the protocol, and these are science-based with acceptable quantitative criteria.

This initial list does not include short chain (C₁₀-C₁₃) chlorinated paraffins, although they were considered for inclusion. It is anticipated that short chain (C₁₀-C₁₃) chlorinated paraffins will be at the top of the priority list for the first round of possible additions, with action expected around 2002.

International Maritime Dangerous Goods Code. Short chain(C10-C13) chlorinated paraffins are classified as marine pollutants by IMDG and require appropriate labelling for marine transport.

Other grades. None of the above information relates to medium chain (C₁₄-C₁₇) or long chain (wax type) chlorinated paraffins, although a formal EU risk assessment is now beginning on medium chain (C₁₄-C₁₇) chlorinated paraffins. This is unlikely to be finalised until 2000 at the earliest.

M.J. WalkerRegulatory Affairs ManagerICI Chlorinated Chemicals

Biocides

New European rules for biocides soon to be agreed

In 1993, the European Commission proposed a Directive to establish a single European market in biocides by introducing a harmonised authorisation system, based on assessment of risks to people and the environment, together with consideration of efficacy. Negotiations on the Directive have now finished and it is likely to be published in mid-March after formal adoption by the European Parliament and European Commission. All member states will then have 24 months to implement what is a very complex and technical Directive. In the UK this will be carried out by the Health and Safety Executive, in close consultation both with other Government Departments and the sectors of industry which will be affected by it. The purpose of this article now is to provide more information on what the Directive will entail, how it might affect you, and what HSE is doing to prepare for its implementation.

What exactly is a biocidal product?

The formal definition of biocidal products given in the Directive is:

Active substances and preparations containing one or more active substances, put up in the form in which they are supplied to the user, intended to destroy, deter, render harmless, prevent the action of, or otherwise exert a controlling effect on any harmful organism by chemical or biological means.

This means that the scope of the Directive is very wide. Basically, any product designed to control unwanted organisms, which is not a plant protection product, a medicine, a veterinary medicine, a cosmetic or a food additive is within the scope of the Directive. As well as covering non-agricultural pesticides currently controlled under the Control of Pesticides Regulations 1986 ­ such as wood preservatives, public hygiene insecticides, masonry biocides and anti-fouling paints ­ the Directive will deal with disinfectants and a number of other specialist products. A full list of the 23 product types covered by the Directive is given in Table I.

Table I:The 23 product types of the Biocidal Pro

What will the Directive do?

The Directive has as its objectives:

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  harmonisation of the European market for biocidal products and their active substances;

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  a high level of protection for humans and the environment.

The harmonisation of the internal market is likely to be of more direct benefit to those industries where controls already exist. However, the removal of barriers to trade will not be at the expense of reducing health and environmental protection.

How will the Directive work?

Ultimately only those biocidal products which contain an active substance which is listed in Annex I of the Directive will be authorised for use.

When the Directive has been implemented in all member states existing and new active substances will be evaluated to ascertain whether or not they will be included in the Annex I list. Both processes will require industry to submit data, with a system of data protection. The data will be evaluated by member states with decisions as to the Annex I listing being taken at the European Community level. There will be an administrative fee charged for this process. The review of existing active substances will last for ten years and will be controlled by a regulation, which has yet to be negotiated. During this transition period existing national rules in member states with regard to the marketing of biocidal products containing existing active substances will continue to apply until such time as active substances are added to, or refused entry to, the Annex I list.

Once an active substance is listed on Annex I, products that contain it can be authorised for marketing in individual member states by national competent authorities, provided any necessary data have been supplied and any conditions put on the Annex I listing are met. Once a product has been authorised in the first member state, it will be possible for it to be mutually recognised and therefore authorised by other member states (provided relevant conditions are similar). However, there will have to be an application to other member states, and again there will be an administration fee for this process.

How will decisions on authorisations be taken?

The granting of authorisations will be dependent on:

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  the active substance being listed in Annex I;

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  the submission of data in accordance with the data requirements set out in Annexes II, III and IV of the Directive;

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  the evaluation of data in accordance with the Common Principles (Annex VI).

The Directive contains streamlined measures for "low risk" biocides and "basic" substances:

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  a low risk biocidal product is one that is considered to pose only a low risk to humans, animals and the environment and contains as active substance(s) only one or more of those listed in Annex IA of the Directive;

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  a basic substance is classed as a substance, which is listed in Annex IB, whose major use is non-pesticidal but which has some minor use as a biocide. The Directive lists carbon dioxide, nitrogen, ethanol, 2-propanol, acetic acid and kieselguhr as examples of potential basic substances.

Who will take the decisions?

For existing and new active substances, the data submitted for Annex I, IA, or IB listing will be evaluated by the competent authority in the relevant member state on behalf of the European Union as a whole. In Britain the competent authority will be the Health and Safety Executive. The ultimate decision on Annex I listing will rest with the Standing Committee on Biocidal Products. This will be a European community level group made up of member states' representatives and chaired by a representative of the European Commission.

Decisions on the authorisation on biocidal products will be taken at the member state level by the relevant competent authority. In Britain this again will be the Health and Safety Executive.

When will your products be affected by the Directive?

Although the Directive will be implemented in mid-March 2000 it will have no immediate effect. In fact it may have no direct effect for several years for many products because of the transition period. It is during this period, that will take up to ten years, that existing active substances will be reviewed for possible inclusion in Annex I. Until they have been reviewed existing active substances and products that contain them will be able to stay on the market ­ subject to existing control measures.

Will there by any guidance?

The Health and Safety Executive will be producing a comprehensive set of guidance on the biocidal products regime. Among other things this will include:

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  guidance on the transitional arrangements;

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  guidance on the regulations themselves;

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  guidance for applicants.

All the guidance will be produced in full consultation with industry ­ so that we can be sure that it suits your needs and is easy to understand and follow.

So what should you do now?

If you are a manufacturer, formulator or importer of biocidal products and would like to be kept up-to-date with progress with implementing the Directive, or consulted over the draft regulations and guidance written to implement the Directive then send us your name and address, together with an indication of your interest in the Directive ­ such as product type ­ and we will add you to our list of contacts.

We aim to publish more articles as the Directive is implemented and hope that this one has given you an idea of what is to come.

If you should require any further information at this stage, please contact:

Dr Alex Tasavalos, HD D4: Pesticides Registration Section, Health and Safety Executive, Magdalen House, Stanley Precinct, Bootle L20 3QZ. ,Tel: 0151 951 3888; Fax: 0151 951 3317; e-mail: alexander.tasvalos@hse.gov.uk

or: Philip Clarke, HD B3: Biocides Policy Section, Health and Safety Executive, Rose Court, 2 Southwark Bridge, London SE1 9HS. Tel: 0171 717 6976; Fax: 0171 717 6199; e-mail: philip.clark@hse.gov.uk