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CSA Z432 Safeguarding of Machinery — What’s new in 2016?


November 24, 2015
By Douglas Nix

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Oct. 23, 2015 – According to a recent paper from Dr. Yuvin Chinniah1, in 2008 alone, three workers were killed everyday working with machinery, adding up to nearly 1,100 fatalities.

Similar numbers were seen in the United States in 2005, with about 1,000 worker fatalities occurring due to machinery2. Accidents occur for a wide variety of reasons, but inadequate safeguarding is among the leading causes. Globally, many machinery safety standards have been developed. In Canada, CSA Z432 – Safeguarding of Machinery provides guidance on risk assessment and the design of safeguarding for machines used in Canada. Federal, provincial and territorial government regulators, machine builders, integrators, employers, and users reference this standard across the country.

Technical standards go through regular revisions to help keep the content current, and to give the Technical Committees the opportunity to correct problems and clarify issues that users have found when using the document. CSA Group started this process with CSA Z432 in 2014.

CSA Z432 has a long history, stretching back to the first edition in 1994. Each edition has advanced the practice of safety in Canada, providing designers, manufacturers, users, integrators and regulators with a comprehensive guide to the design of safe machinery for the Canadian workplace. The third edition, when published in 2016, will further advance this practice in a number of important ways.

Harmonization of standards is extremely important for business. The closer Canadian standards get to those of our neighbours and the rest of the world, the lower the technical barriers to trade become. Technical barriers to trade are differences in technical requirements in regulation or in standards that result in the exclusion of products or services from a jurisdiction. CSA has an overriding principle of harmonization where possible with the international standards produced by ISO and IEC or other international or North American standards bodies, aimed at reducing technical barriers to trade. Many Canadian standards are already closely harmonized with the U.S., like the Canadian Electrical Code and the U.S. National Electrical Code, and we are coming closer in many other areas.

In this latest edition of CSA Z432, there are a number of significant changes that are being considered to be driven least in part by technical harmonization. There is also a proposed adoption of an ISO standard that was driven by this desire for harmonization.  

Safety distances
The concept of safety distances for reaching up, over and through guards and guarding systems in the area of machine safety is a critical topic for keeping Canadian workers safe from injury. This is also a frequent area of questions and confusion for end-users, and as such, the CSA Technical Committee has been spending a great deal of time and effort reviewing the safety distance parameters referenced in ISO Standards as it compares to the historic safety distance values within the CSA Z432 document, as well as considering how best to present this information to end-users for maximum clarity.  

The existing Table 3, Minimum distance from hazard as a function of barrier opening size, has origins in a study done by Vaillancourt and Snook3. For readers familiar with the U.S. OSHA guard openings table, the values in Table 3 and in 29 CFR 1910.217 Table O-104 are not the same nor are they the same as those in ISO 13857. All of the guard opening tables have been used safely for many years, so whether you choose CSA Z432 Table 3, OSHA 1910.217 Table O-10, or ISO 13857 when designing guards, the result is reduced risk to users for openings in guards.

The Technical Committee is proposing to adopt ISO 13857, Safety of machinery — Safety distances to prevent hazard zones being reached by upper and lower limbs as a Canadian national standard and incorporate some components of this within the third edition of CSA Z432. This document went through public review in recent months and is anticipated to publish later in 2015. This proposed decision will help Canada stay in step with international guarding requirements, ensuring harmonization with International requirements.

Risk assessment
Risk assessment has been a part of Z432 since the first edition in 1994. The second edition expanded the guidance provided to users, harmonizing with the approach in ISO 12100-1:2003. This harmonization helped people importing machinery built to International and European standards.

In 2012, CSA published CSA Z1002 – Occupational health and safety — Hazard identification and elimination and risk assessment and control. This groundbreaking standard provides organizations with a risk assessment methodology that can be applied to any product, process or service. The standard is part of the CSA Z1000 OHS Management series, however, it is designed so that it can be used whether an organization has a formal OHS management system or not. The CSA Z1002 approach is also rooted in ISO 12100, and this is the proposed basis for further harmonization in the third edition of CSA Z432.

Functional safety
Clause 8 of CSA Z432 is anticipated to continue as the source of information on functional safety, or “control reliability” as it has been known. The Technical Committee is proposing to harmonize this clause with the International standards, directing machine builders to conduct functional safety analyses using ISO 13849 or IEC 62061 as appropriate.

Review of safety-related controls post-design is problematic, as there are key pieces of information that are only known to the designers and their organization. To facilitate the use of the standard in evaluating existing machinery, the Technical Committee is proposing that users be allowed to consider the architecture of the safety-related controls alone. This proposed approach would significantly simplify the review process and eliminate the need to address organizational aspects that contribute to functional safety performance but which are not directly related to the architecture of the safety-related controls or the components used in those controls.

These proposed changes would bring the Canadian requirements into alignment with the rest of world with respect to functional safety requirements, and allow latitude for the types of post-manufacture reviews that are done in Ontario.
 
Guards and safeguarding devices
Significant revisions are being proposed to Clauses 9 and 10, Performance requirements and Application requirements for safeguarding devices. The content of the existing clauses is being reviewed and revised to bring it into alignment with U.S. and International requirements. The flow and structure of these clauses are proposed to be improved to help users in applying the information.

Lasers in industry
Lasers are frequently incorporated in machinery for metrology, control and for processes like welding and cutting. The previous editions of Z432 included some information related to the use of lasers in these ways, but since Canada did not have a laser safety standard in the CSA Group library, and since federal regulations do not regulate these applications, there was much confusion about the requirements. Since 2004, IEC 60825-1, Safety of Laser Products: Equipment Classification, Requirements and User’s Guide has been adopted as CSA E60825-1. This document is used to certify new laser products but does not include specific requirements for users. For this information, we go to the U.S. ANSI Z136 family of standards.

The proposed revisions to the CSA Z432 text cover the classes of lasers from the current edition of CSA E60825-1, and provide guidance on the need for Laser Safety Officers (LSO) in manufacturing facilities in Canada. There is a proposed supporting Annex that includes a flowchart to help OHS personnel decide on the need for a LSO in their facilities.

Annex material
The Annexes continue to be developed, but the Technical Committee has been working hard to modernize and improve much of what existed, and are proposing the addition of more information that they believe users will find helpful.

Public review
The normative text — the body of the standard, excluding the Annexes — will be made available for public review through the CSA Group Public Review system sometime this fall. Editorial work is in progress at the moment and when that is completed, the draft will be opened for public review and comment. If you are interested in participating, visit publicreview.csa.ca. Occupational Health and Safety Standards, including CSA Z432, can be found at publicreview.csa.ca/Home/Category/010.

Conclusions
Engineers are trained to provide solutions to problems that won’t endanger the safety of people using the product, process or service that they have designed, and to do that they need data. Business leaders want to leverage existing knowledge to gain advantages over competitors. Workers want to work in safe workplaces and be assured to go home each and every day without injury. Standards like CSA Z432 and CSA Z1002 provide all of that to businesses, engineers, workers and our nation. Leveraging the combined knowledge of the technical expert contributors, CSA Group provides standards that give Canadian businesses the basis to compete effectively, efficiently and safely. Continuous revision of standards ensures that the latest proven approaches can be implemented by almost any business, without the need to “reinvent the wheel.” Involvement in standards writing is a great way for businesses to lead the way, contributing to the economy and their own success in meaningful and lasting ways.

Douglas Nix, C.E.T., SM-IEEE, is managing director at Compliance Insight Consulting. He has more than 25 years of engineering technology expertise, though he has focused on risk assessment and machinery safety since 1996.

References
[1] Y. Chinniah, “Analysis and prevention of serious and fatal accidents related to moving parts of machinery,” Saf. Sci., vol. 75, pp. 163–173, 2015.
[2] M. T. Bulzacchelli, J. S. Vernick, G. S. Sorock, D. W. Webster, and P. S. J. Lees, “Circumstances of fatal lockout/tagout-related injuries in manufacturing,” Am. J. Ind. Med., vol. 51, no. 10, pp. 728–734, 2008.
[3] D. R. Vaillancourt and S. H. Snook, “A Review of Machine-Guarding Recommendations,” Appl. Ergon., vol. 26, no. 2, pp. 141–145, 1995.
[4] “Mechanical power presses. – 1910.217.” [Online]. Available: https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9841. [Accessed: 02-Sep-2015].