This online guide to machine risk assessment provides useful tips and advice for machine builders and users of existing equipment. By Jon Severn, MachineBuilding.net editor.
Machine risk assessments are the key to machinery safety, paving the way for risk reduction measures that are both effective and economical. Here in the UK, the Health and Safety at Work etc Act 1974 (HSWA) states that it shall be the duty of every employer to ensure "so far as is reasonable practicable" (SFAIRP) the health, safety and welfare at work of all his employees - which implies that the cost of safeguarding should be commensurate with the risks. This is not the same elsewhere, and this important phrase in British health and safety law was recently challenged by the European Commission, which claimed that the use of the phrase did not implement the Framework Directive 89/391/EEC. However, the European Court of Justice (ECJ) dismissed the European Commission's case and ordered it to pay the UK Government's costs. There is a press release about this case on the HSE's website and an article here that explains What does 'as low as reasonably practicable' mean?.
Machine Risk Assessment definition
In EN ISO 12100:2010, risk assessment is defined as overall process comprising a risk analysis and a risk evaluation. These terms are, themselves, defined as:
- risk: combination of the probability of occurrence of harm and the severity of that harm
- risk analysis: combination of the specification of the limits of the machine, hazard identification and risk estimation
- risk evaluation: judgement, on the basis of risk analysis, of whether the risk reduction objectives have been achieved
MachineBuilding.net has details of a number of companies that offer software-based utilities for performing risk assessments, as well as companies that can carry out risk assessments on a contract basis. These tend to be based on the requirements of BS EN ISO 12100:2010, Safety of machinery. General principles for design. Risk assessment and risk reduction (see below for more information about machinery risk assessment standards).
Machine risk assessment software
Using a software-based tool is likely to be quicker, easier and less susceptible to human error than working through a risk assessment from scratch - though care must be taken to ensure that all hazards are identified and all risks assessed when the software is presenting the user with generic checklists.
Procter Machine Guarding has a free free Risk Assessment Calculator that is based on BS EN ISO 12100:2010. Built on a spreadsheet, the user-friendly Risk Assessment Calculator uses checklists and look-up tables to enable risk assessments to be carried out on almost any static machinery. For each identified hazard, the user enters the data and selects values for:
- Likelihood of Occurrence
- Frequency of Exposure
- Degree of Possible Harm
- Number of Persons at Risk
A Hazard Rating Number (HRN) and Risk Level are calculated automatically, so the user can see where further action may be necessary; the displayed HRN values enable users to set priorities when not all issues can be addressed immediately.
Another useful software package is available from IBF Automatisierungs und Sicherheitstechnik, known as IBF Safexpert. This software is currently (28 November 2013) at version 8.1, but you can read a review of IBF Safexpert 5.4 on MachineBuilding.net. IBF Safexpert was developed for CE marking and incorporates an EN ISO 12100 risk assessment procedure (previously EN ISO 14121-1).
For engineers using the Sistema software for EN ISO 13849-1 Performance Level Calculations, Docufy Machinery Safety is a useful tool for machine risk assessments and CE marking (Docufy is also useful for those not working with Sistema). Docufy provides a structured approach to risk assessments, plus it has other benefits such as a facility for storing data about standards and Directives, and, importantly, Docufy can be integrated with Sistema.
Machine risk assessment guides
If you just want written guidance, tips and advice on machine risk assessments, there is a chapter in the Sick publication Six Steps to a Safe Machine. For more information, see Sick's free guide to machinery safety - a review. Similarly, the updated Practical Guide to Machinery Safety, published by TUV SUD Product Service (previously Laidler Associates), contains a section devoted to risk assessment and hazard analysis. The Schneider Electric Safe Machinery Handbook also has a chapter on risk assessment.
Another useful resource is the book published by BSI, Risk management of machinery and work equipment. As well as considering issues relating directly to the design, manufacture and use of machinery, this guide also covers corporate risk management.
Safebook 4, the latest edition of Rockwell Automation's book subtitled Principles of Machine Safety: Legislation, Theory and Practice, also includes a chapter on risk assessment.
Machine risk assessment advice, consultancy and training
For those who would prefer to seek advice and guidance from consultants, the following companies offer machinery safety and/or risk assessment services:
- Glover Associates & Consulting Ltd
- Health & Safety Compliance Engineering
- ISS Safety Ltd
- Machinery Safety, Compliance Services, MSCS (NaN Ltd)
- Pilz Automation Technology
- PR Safety Ltd
- Safe Machine Ltd
- Spiers Engineering Safety (Spiers Ltd)
- Suffolk Technical & Logistics Ltd
- Technology International (Europe) Ltd
- TUV Rheinland Group
- TUV SUD Product Service
Training is also available from many of the above organisations, plus risk assessment training courses are run by the HSL (Health and Safety Laboratory), which is an agency of the UK's HSE (Health and Safety Executive).
Machinery risk assessment standards
The current standard relating to machine risk assessments is ISO 12100:2010, the equivalents of which are EN ISO 12100:2010 in Europe and BS EN ISO 12100:2010 in the UK. Several years ago EN 1050 (BS EN 1050 in the UK) was the risk assessment standard for machinery, but that was superseded by, first, EN ISO 14121-1 (BS EN ISO 14121-1 in the UK), then EN ISO 12100:2010 (BS EN ISO 12100:2010 in the UK). This current standard is harmonised to the Machinery Directive, which means that complying with it is not a legal requirement but will normally be sufficient to meet the applicable Essential Health and Safety Requirements of the Machinery Directive 2006/42/EC (the standard is said to provide a 'presumption of conformity' with the EHSRs). Note that the Machinery Directive only applies in Europe, and the current standard is identical to ISO 12100:2010, which is an international standard, so machine builders exporting to other countries should be able to use this standard and be confident of meeting their obligations regarding machinery risk assessments. For more information about machine risk assessment standards, see these articles: EN ISO 12100:2010 combines EN ISO 12100 and EN ISO 14121-1 and The differences between EN 1050 and EN ISO 14121-1.
Additional news and information will be added to this online machinery risk assessment guide as it becomes available.
Jon Severn, Editor, MachineBuilding.net