Machinery Safety 101

Presence Sensing Devices – Reaching over sensing fields

I recently heard about an application question related to a light curtain where a small gap existed at the top of the sensing field, between the last beam in the field and the surrounding structure of the machine. There was some concern raised about the gap, and whether or not additional guarding might be needed to close…

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Interlocking Devices: The Good, The Bad and the Ugly

Note: A shorter version of this article was published in the May-2012 edition of  Manufacturing Automation Magazine. When designing safeguarding systems for machines, one of the basic building blocks is the movable guard. Movable guards can be doors, panels, gates or other physical barriers that can be opened without using tools. Every one of these…

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Hockey Teams and Risk Reduction or What Makes Roberto Luongo = PPE

Canucks Hockey Flag

Special Co-Author, Tom Doyle Last week we saw the Boston Bruins earn the Stanley Cup. I was rooting for the green, blue and white, and the ruin of my voice on Thursday was ample evidence that no amount of cheering helped. While I was watching the game with friends and colleagues, I realized that Roberto…

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Retained fastenings for fixed guards

If you are building machinery that will be CE marked or is subject to the EU Machinery Directive, you need to read this article at MachineBuilding.net This article reviews some of the retained fastenings that are available for use on fixed machine guards, as required by the new Machinery Directive 2006/42/EC and the guarding standard…

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Understanding the Hierarchy of Controls

The Hierarchy of Controls illustrated as an inverted triangle with each level of the hierarchy written one above the other, starting with Inherently Sfe design, then Engineering Controls, then Information for Use, then Administrative Controls and finally descending to PPE at the bottom. An arrow with the text "Effectiveness" on it runs parallel to the triangle and points downward from Inherently safe design to PPE.

(Eds. note: This article was originally written in 2011 and was updated in Nov. 2018.) The “Hierarchy of Controls” is one approach to risk reduction that has become entrenched in the Occupational Health and Safety (OHS) sector. There are other approaches to risk reduction which are equally effective but are less rigidly structured. If you…

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