Machine guards are normally designed to prevent workers from accessing hazardous parts of machinery and to protect against ejected parts. However, there is another risk that is not always given adequate consideration, namely hazardous substances emitted by machinery, which is covered in BS EN ISO 14123-1:2015.
BSI published BS EN ISO 14123-1:2015, Safety of Machinery. Reduction of risks to health resulting from hazardous substances emitted by machinery. Part 1: Principles and specifications for machinery manufacturers, in November 2015, with this UK version of an international standard superseding and replacing BS EN 626-1:1994+A1:2008. Unfortunately, because of the timing, the new standard is not in the updated list of Machinery Directive Harmonised Standards that was published on 15 January 2016, so this list still includes EN 626-1 (BS EN 626-1 being the UK equivalent). Nevertheless, machine builders and guard designers are advised to work to BS EN ISO 14123-1, as this should mean their designs meet or exceed the requirements laid down in BS EN 626-1. As with the standard it is replacing, BS EN ISO 14123-1 is a Type-B1 standard because it is a generic safety standard dealing with one aspect of safety that can be applied to many different classes of machinery.
The first few pages of BS EN ISO 14123-1 follow the expected format of:
- National foreword
- Preface from CEN
- European foreword
- Annex ZA (explaining the relationship between the European standard and the essential requirements of the EU Machinery Directive 2006/42/EC)
- Contents listing
- Normative references
- Terms and definitions
After that comes the standard's main technical content:
- Risk assessment
- Types of emissions
- Requirements and/or protective measures for elimination and/or reduction of risk
- Information for use and maintenance information
- Verification of safety requirements and/or protective measures
- Annex A, Examples of protective measures for reduction of exposure to hazardous substances
At the end there is a Bibliography, though this only lists three publications.
BS EN ISO 14123-1 is not a particularly long standard, running to just nine pages of technical content, but it is an important standard for machine designers and anyone designing or specifying machine guarding. The second part of the same standard, BS EN ISO 14123-2:2015, Methodology leading to verification procedures, should also be consulted if measures are being implemented to reduce the risks associated with emissions of hazardous substances.
Hazardous substances are defined as any chemical or biological agent that is hazardous to health, but note the exclusions in the scope: substances that are a hazard to health solely because of their explosive, flammable or radioactive properties or their behaviour at extremes of temperature or pressure. A further point to note is that the definition of hazardous substance also refers the reader to EC Regulation 1272/2008 (classification, labelling and packaging of substances and mixtures), which is in the bibliography, and there is a note to the effect that definitions of chemical agent and biological agent can be found in EN 1540, Workplace exposure. Terminology (also in the bibliography).
Clause 4, Risk assessment, refers to ISO 12100 (BS EN ISO 12100:2010 Safety of machinery. General principles for design. Risk assessment and risk reduction), but also gives useful information relating to hazardous substances. This includes an indication of how hazardous substances can be generated and the phases of the machine's lifecycle during which hazardous substances may be present. In addition Clause 5, Types of emissions, provides more information that would help in identifying potential hazardous substances. Nevertheless, it is essential that risks are identified during the risk assessment, otherwise it is unlikely that adequate steps will be taken to eliminate or reduce the risks. For instance, subclause 5.1.3 gives examples of airborne hazardous substances, one of which is the biological agent legionella pneumophila, the cause of Legionnaires' Disease; many machine builders are unaware that there is a risk of this agent being present in any system that stores, reuses or recirculates water that can also be released as a spray or aerosol.
Subclauses 5.1.4 and 5.1.5 refer to evaluations, measurements, air sampling and analysis of airborne contaminants. However, it will often be the case that airborne contaminants are only present in the event of a machine or process malfunction, or if out-of-specification raw materials or components are used. For a machine builder, it may therefore not be possible to make the measurements that would, ideally, be required.
In clause 6, Requirements and/or protective measures for elimination and/or reduction of risk, there are two phrases that should be noted:
- Risks from exposure to hazardous substances shall be reduced as far as practical, taking into account scientific and technical methods and limits relating to exposure and the external environment.
- The manufacturer shall apply the following principles, in the order given, taking into account the state of the art.
In other words, measures need not be implemented if the cost, time or trouble required is not commensurate with the resulting reduction in risk; and, when assessing candidate risk reduction measures, technologies that are generally available at the time should be considered.
Initially the reader may be disappointed that clause 6 contains no practical advice about protective measures, but there a note referring to Annex A, Examples of protective measures for reduction of exposure to hazardous substances. Indeed, many readers are likely to find Annex A one of the most useful sections of the standard, even though it is only 'informative.' Annex A is divided into three:
- Elimination and prevention of risk
- Risk reduction
- Information and other protective measures regarding residual risks
All three provide helpful information in the form of bullet-point lists of examples.
Compared with standards such as BS EN ISO 12100 and BS EN ISO 14120 (the primary machine guarding standard), BS EN ISO 14123-1 is of less importance. Nevertheless, machine builders and guard designers need to be aware of it and have an understanding of its contents before they can decide whether or not the emission of hazardous substances is a risk that needs to be addressed.
Procter Machine Guarding has prepared numerous technical articles relating to machine safety standards, as well as guides, white papers and calculators. These can all be accessed free of charge from the downloads section of the company's website, or contact Procter Machine Guarding to discuss projects requiring guarding against hazardous emissions.