Canada Adopts ISO 13857 — Safety Distances

This entry is part 4 of 7 in the series Guards and Guard­ing

Safety Distances

ISO 13857 2008, Figure 2 - Safety Distance for reaching over a protective structure
ISO 13857 2008, Fig­ure 2 — Reach­ing Over Pro­tec­tive Struc­ture

As part of the work on the 3rd Edi­tion of CSA Z432, Cana­da has decid­ed to adopt ISO 13857 as CAN/CSA-ISO 13857. The stan­dard was adopt­ed in 2015 with­out tech­ni­cal devi­a­tions.

Why ISO 13857?

CSA Z432 has long had por­tions of the infor­ma­tion in ISO 13857 in its annex­es — Annex C has tables for reach­ing through open­ings and reach­ing over struc­tures, much like the one above, that users have found use­ful over the years. Unfor­tu­nate­ly, these tables have also proved a bit con­fus­ing, as they are some­what dif­fer­ent than CSA Z432-04 Table 3. While nei­ther set of safe-dis­tance val­ues is less safe, the val­ues in Table 3 are very sim­i­lar to those used in the USA, which was the orig­i­nal source for that infor­ma­tion. The tables in CSA Z432-04 Annex C are infor­ma­tive, mean­ing they are pro­vid­ed as a help­ful guide to apply­ing the stan­dard, but they are NOT a manda­to­ry part of the stan­dard.

When Z432 was first being devel­oped in the late 1980’s, most machin­ery prod­ucts were com­ing to Cana­da from the US, so har­mon­i­sa­tion with US OSHA guide­lines was more impor­tant than har­mon­is­ing inter­na­tion­al­ly. Today, import of machin­ery from the EU is com­mon, and Cana­di­an export of machin­ery around the world is part of doing busi­ness. CSA’s Safe­ty of Machin­ery Tech­ni­cal Com­mit­tee decid­ed to help man­u­fac­tur­ers and importers by har­mon­is­ing Canada’s stan­dards with the Inter­na­tion­al Stan­dards by adopt­ing ISO 13857 as a Cana­di­an Stan­dard.

Fixing the Problem

While the CSA Z432 com­mit­tee was work­ing on revis­ing the stan­dard in 2014/15 it was rec­og­nized that Annex C had caused a lot of con­fu­sion. The com­mit­tee also rec­og­nized that there was no evi­dence that Table 3 or ISO 13857’s tables lead to “less safe” or “safer” machine designs. Since Table 3 didn’t deal with any­thing except open­ings in guard­ing, there was a big gap if Annex C was com­plete­ly dis­card­ed. Users need­ed infor­ma­tion on reach­ing over guard­ing, and on reach­ing through guard­ing where the open­ing was big enough to get an arm through up to the shoul­der, but there were oth­er obstruc­tions inside that might lim­it access to haz­ards. This infor­ma­tion was avail­able in ISO 13857. The deci­sion was tak­en by the com­mit­tee to adopt ISO 13857:2008 as a Cana­di­an stan­dard, and so it became CA/CSA-ISO 13857–2015.

When CSA Z432-16 was issued in Octo­ber of 2016, the nor­ma­tive text includ­ed both stan­dards. The old Table 3 has been cor­rect­ed (the SI con­ver­sions in the 2004 edi­tion were…off) and incor­po­rat­ed as Table 10.1, and the text allows that CAN/CSA-ISO 13857 can be used instead.

The Bottom Line

Cana­di­an machine builders can now use EITHER CSA Z432-16, Table 10.1, OR ISO 13857’s tables. They both result in safe designs. The big dif­fer­ence is that Table 10.1 will often result in a some­what more com­pact machine, BUT, ISO 13857 has fin­er gra­da­tions in the reach-through tables, and also allows for users old­er than 14 or younger than 14, so may be more advan­ta­geous depend­ing on the end-use envi­ron­ment and the spe­cif­ic design issues you are required to con­sid­er.

One final point: ISO 13857 is under review, with a new edi­tion expect­ed in 2017. Pro Tip: The basic tables remain unchanged, and there is lots of new infor­ma­tion in the com­ing update.

Public Review

If you are inter­est­ed in review­ing and com­ment­ing on this adop­tion, please vis­it the CSA Pub­lic Review Page for the stan­dard. Com­ments close 13/07/2015.


Iden­ti­fi­er: Z13857

Title: Safe­ty of machin­ery — Safe­ty dis­tances to pre­vent haz­ard zones being reached by upper and low­er limbs (Adop­tion with­out devi­a­tions) (New Stan­dard) Expiry date: 13/07/2015

This Inter­na­tion­al Stan­dard estab­lish­es val­ues for safe­ty dis­tances in both indus­tri­al and non-indus­tri­al envi­ron­ments to pre­vent machin­ery haz­ard zones being reached. The safe­ty dis­tances are appro­pri­ate for pro­tec­tive struc­tures. It also gives infor­ma­tion about dis­tances to impede free access by the low­er limbs (see 4.3).

ed. note: This post was cor­rect­ed and updat­ed 28-Aug-2017.

Series Nav­i­ga­tionTrapped Key Inter­lock­ingHow to Apply a Safe­ty Edge to a Machine Guard — Part 1: Pres­sure-sen­si­tive devices

Author: Doug Nix

Doug Nix is Managing Director and Principal Consultant at Compliance InSight Consulting, Inc. ( in Kitchener, Ontario, and is Lead Author and Senior Editor of the Machinery Safety 101 blog. Doug's work includes teaching machinery risk assessment techniques privately and through Conestoga College Institute of Technology and Advanced Learning in Kitchener, Ontario, as well as providing technical services and training programs to clients related to risk assessment, industrial machinery safety, safety-related control system integration and reliability, laser safety and regulatory conformity. For more see Doug's LinkedIn profile.