Machinery Safety 101

Canada Adopts ISO 13857 – Safety Distances

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.

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