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.