EU changes direction on EN ISO 13849–1

Update on EN ISO 13849–1 manda­to­ry imple­men­ta­tion date.

In a post on 15-Sep I report­ed that the Euro­pean Union had decid­ed to delay the manda­to­ry imple­men­ta­tion date of  EN ISO 13849–1 for an addi­tion­al three years. This report was based on infor­ma­tion obtained from an inter­nal source at the Euro­pean Com­mis­sion and has since been reversed by that same source.

Mr. Glyn Gar­side pro­vid­ed the fol­low­ing update to this impor­tant sto­ry:

It has been wide­ly report­ed, but nev­er con­firmed, that the EU com­mis­sion had accept­ed the CEN pro­pos­al to extend the date of ces­sa­tion of pre­sump­tion of con­for­mi­ty of EN 954–1:1996 until the end of 2012. THESE REPORTS HAVE NOW BEEN AUTHORITATIVELY DENIED.

(By the way, this dis­cus­sion of dates of ces­sa­tion of pre­sump­tion of con­for­mi­ty only affects the Euro­pean stan­dards, EN 954–1 and EN ISO 13849–1. Inter­na­tion­al stan­dard ISO 13849–1 is obvi­ous­ly con­trolled by ISO and not by CEN or the EU. The cur­rent edi­tion of ISO 13849–1 is 2006, essen­tial­ly iden­ti­cal to EN ISO 13849–1 : 2008.)

At this point the pos­si­bil­i­ty of an exten­sion of the tran­si­tion from EN 954–1 to EN ISO 13849–1 remains con­tro­ver­sial, con­fused and IMHO uncer­tain. (There’s been approx 3 years tran­si­tion peri­od already.) If I were still a man­u­fac­tur­er, I would not want to wait until Dec 29th to find out if I could still ship my prod­uct using EN 954–1!

The reports of an exten­sion were based on an email sent ear­li­er this month (3rd Sept) by a CEN employ­ee. How­ev­er, the EU Com­mis­sion nev­er con­firmed the report, and on Sep­tem­ber 24th the same CEN employ­ee, Marie Poidevin, has writ­ten,
> “We have been informed today by the Euro­pean Com­mis­sion […] that con­trary to what was expressed in
> my pre­vi­ous mes­sage sent on the 3rd of Sep­tem­ber, EN 954–1 will not give pre­sump­tion of con­for­mi­ty
>  to the new MD 2006/42/EC until fur­ther notice.
> “Indeed, due to dis­cus­sions fol­low­ing the announce­ment made below, the EC wish­es to gath­er experts’
> views and, there­fore, this issue will be dis­cussed at the next Machin­ery Work­ing group to be held on
> the 7–8th Decem­ber.”

A relat­ed email from Ian Fras­er (“EC Pol­i­cy Direc­tor for the Machin­ery Direc­tive”), dat­ed 2009-09-18 states,
“Fol­low­ing the dis­cus­sion at the meet­ing of the Machin­ery Work­ing Group held on 7 and 8
July 2009, we have received a num­ber of ques­tions con­cern­ing the tran­si­tion from stan­dard
EN 954–1 to stan­dard EN ISO 13849–1 on safe­ty-relat­ed parts of con­trol sys­tems.
At the meet­ing of the Machin­ery Work­ing Group, there was gen­er­al agree­ment on two
1. Man­u­fac­tur­ers who apply stan­dard EN ISO 13849–1 ben­e­fit from a pre­sump­tion of
con­for­mi­ty, even if the har­monised C-type stan­dard relat­ing to the machin­ery con­cerned still
refers to the cat­e­gories of EN 954–1;
2. Har­monised C-type stan­dards that refer to the cat­e­gories of EN 954–1 con­tin­ue to con­fer a
pre­sump­tion of con­for­mi­ty until they are amend­ed to refer to stan­dard EN ISO 13849–1.
These con­clu­sions will be record­ed in the min­utes of the meet­ing.

Dur­ing the dis­cus­sion, sev­er­al par­tic­i­pants indi­cat­ed that more time was need­ed for the
indus­try, and in par­tic­u­lar for SMEs, to adapt to the new stan­dard. As Chair­man of the
meet­ing, I asked whether it might not be prefer­able to post­pone the date of ces­sa­tion of
pre­sump­tion of con­for­mi­ty for EN 954–1.
In response to this sug­ges­tion, on 30 July 2009, Mr. Steiger wrote to the Com­mis­sion, on
behalf of the CEN Machin­ery Sec­tor, to request that the date of ces­sa­tion of pre­sump­tion of
con­for­mi­ty for EN 954–1 be excep­tion­al­ly post­poned until 31 Decem­ber 2012 […].
The Com­mis­sion will reply to this request from CEN. How­ev­er, giv­en the com­plex­i­ty of the
issues involved, the Com­mis­sion intends to con­sult experts and to seek the opin­ion of the
Machin­ery Work­ing Group to be held on 7 and 8 Decem­ber 2009, before reach­ing a final
Kind regards,

Thanks again to Glyn Gar­side and the EMC-PSTC List Serv­er!

European Commission Delays EN ISO 13849–1 Implementation

The EC has decid­ed to extend the tran­si­tion peri­od for EN 954–1 from 31-Dec-09 to 31-Dec-12, delay­ing the manda­to­ry imple­men­ta­tion of EN ISO 13849–1. How will this affect machine builders and con­trols man­u­fac­tur­ers?

I recent­ly read that the Euro­pean Com­mis­sion has decid­ed to delay the manda­to­ry imple­men­ta­tion of EN ISO 13849–1 2008 and EN 62061. The 2006 edi­tion of ISO 13849–1 moves the bar con­sid­er­ably high­er for machine builders, requir­ing much more exten­sive analy­sis of con­trol reli­a­bil­i­ty require­ments as part of the design cycle. EN 62061 pro­vides a machin­ery spe­cif­ic imple­men­ta­tion of IEC 61508 for  sys­tems includ­ing pro­gram­ma­ble equip­ment in the safe­ty relat­ed parts of the con­trol sys­tem. The orig­i­nal manda­to­ry imple­men­ta­tion date for these stan­dards was 31-Dec-2009. This has now been pushed out to 31-Dec-2012 accord­ing to

[More on the exten­sion of EN 954–1]

[More on the imple­men­ta­tion of EN 62061]


European Union

When EN 954–1 was intro­duced in 1996, it set out a whole new cri­te­ria for the eval­u­a­tion of safe­ty sys­tem con­trol reli­a­bil­i­ty in machin­ery. This stan­dard intro­duced the idea of the famil­iar Reli­a­bil­i­ty Cat­e­gories, B, 1–4. This stan­dard end­ed the days where a sin­gle chan­nel cir­cuit with any con­ve­nient sens­ing device could be con­sid­ered to be accept­able for safe­ty appli­ca­tions in most indus­tri­al appli­ca­tions.

The next few years were chal­leng­ing ones for machine builders and design­ers as they learned to imple­ment these require­ments in their prod­ucts. The con­trol com­po­nents man­u­fac­tur­ers intro­duced broad arrays of con­trol com­po­nents, like guard mon­i­tor­ing relays, emer­gency stop relays and enabling-device relays to assist design­ers by pro­vid­ing build­ing block com­po­nents to sim­pli­fy designs and reduce costs.

The first edi­tion of ISO 13849–1 was pub­lished in 1999. The new ISO stan­dard was essen­tial­ly a straight adop­tion of EN 954–1, bring­ing the doc­u­ment into the ISO devel­op­ment mod­el. Stake­hold­ers were aware that changes to the doc­u­ment were need­ed, and that addi­tion­al clar­i­ty was required to assist design­ers in cor­rect­ly imple­ment­ing the stan­dard. Addi­tion­al tools were envi­sioned to help users bet­ter apply reli­able con­trol design prin­ci­ples in their prod­ucts.

In 2006, the sec­ond edi­tion of ISO 13849–1 was pub­lished, and in May 2007 noti­fied in the Offi­cial Jour­nal of the Euro­pean Union, see OJ 2007/C 104/01. The manda­to­ry imple­men­ta­tion date was set to 31-Dec-2009, and the two-year tran­si­tion peri­od began. Dur­ing this peri­od either the 1999 edi­tion or the 2007 edi­tion could be applied and com­pli­ance with the rel­e­vant por­tions of the EU Machin­ery Direc­tive could be claimed.

North America

It took a bit longer for con­trol reli­a­bil­i­ty to creep into the North Amer­i­can designer’s con­scious­ness. Man­u­fac­tur­ers who were mar­ket­ing prod­uct in the EU became aware of EN 954–1 as they worked on com­pli­ance with the CE Mark­ing direc­tives that applied to their prod­ucts. In the USA, ANSI RIA R15.06 intro­duced con­trol reli­a­bil­i­ty require­ments in the 1999 edi­tion, and soon after CSA pub­lished CSA Z434 which close­ly fol­lowed RIA’s stan­dard with some small but sig­nif­i­cant changes. These stan­dards intro­duced the SIMPLE, SINGLE-CHANNEL, MONITORED SINGLE-CHANNEL and CONTROL RELIABLE def­i­n­i­tions into robot sys­tem design­ers think­ing.

These con­cepts were lat­er includ­ed in CSA Z432, Safe­guard­ing of Machin­ery, and are being incor­po­rat­ed into the ANSI B11 fam­i­ly of machin­ery safe­ty stan­dards. ANSI’s soon-to-be-pub­lished  B11-GSR, Gen­er­al Safe­ty Require­ments, stan­dard will fur­ther embed these con­cepts into US machin­ery safe­ty stan­dards.

Recent amend­ment of ANSI RIA 15.06 by ANSI RIA ISO 10218–1 brings ISO 13849–1 into the North Amer­i­can mar­ket by asso­ci­a­tion, since the ISO robot­ic stan­dard direct­ly ref­er­ences the ISO con­trol reli­a­bil­i­ty stan­dards. How long it will take for Cana­da to fol­low suit is unknown at this time, but CSA Z434 is just start­ing review and may be har­mo­nized with the US, the EU and the Inter­na­tion­al stan­dards.

Need to know more about the US amend­ment of R15.06 by 10218–1? See Jeff Fryman’s report on the RIA web site.


Accord­ing to, “…many man­u­fac­tur­ers are not yet ready to apply the replace­ment stan­dard EN ISO 13849–1.” Sources in the UK have long been con­cerned that many small and medi­um enter­pris­es were hav­ing dif­fi­cul­ty apply­ing EN 954–1, with­out increas­ing the bur­den by adding sig­nif­i­cant­ly more analy­sis to the design task. Con­sul­ta­tions between the EC Machin­ery work­ing group and the Euro­pean Com­mis­sion led to the deci­sion to post­pone the date.


What are the impli­ca­tions of this delay?

First, I think that many machine builders will heave a sigh of relief, hav­ing gained a bit more than three years grace on the dead­line. This will give them more time to work on their designs and to com­plete third-par­ty eval­u­a­tions used to sup­port their Dec­la­ra­tion of Con­for­mi­ty. This will also allow those who are inclined to “slide” three more years to delay doing any­thing.

On the oth­er hand, the con­trols man­u­fac­tur­ers spent at least the last two years gear­ing up their prod­ucts to meet design­ers require­ments under the new stan­dard. One of the sig­nif­i­cant require­ments is the pro­vi­sion of fail­ure rate data for com­po­nents from inter­lock switch­es to relays and light cur­tains to emer­gency stop but­tons. Sig­nif­i­cant test­ing is required to be able to pro­vide MTTFd or B10d num­bers usable in the design analy­sis.

For com­pa­nies that pro­vide train­ing in this area, more time is now avail­able to get clients trained, but some of the urgency has been removed, poten­tial­ly extend­ing the return on invest­ment in devel­op­ment of cours­es on this stan­dard.

Ulti­mate­ly, the losers are the users of the equip­ment. This stan­dard pro­vides an oppor­tu­ni­ty to sig­nif­i­cant­ly improve the reli­a­bil­i­ty of the safe­ty sys­tems on indus­tri­al machines. The exten­sion only delays this need­ed improve­ment by three years, and by an untold num­ber of oth­er­wise pre­ventable injuries. While I under­stand the pres­sures that the old dead­line put on man­u­fac­tur­ers, it is my expe­ri­ence that this kind of pres­sure is fre­quent­ly nec­es­sary to dri­ve the changes that soci­ety demands. While these changes direct­ly affect those mar­ket­ing in the EU today, the changes to the North Amer­i­can stan­dards mean that this impor­tant stan­dard will soon be a part of North Amer­i­can designer’s think­ing as well. It will be inter­est­ing to see what oth­er effects this change has over the next three years.

Many thanks to Glyn Gar­side for send­ing me a few cor­rec­tions to the orig­i­nal post! Mr. Gar­side is a reg­u­lar read­er and con­trib­u­tor to the EMC-PSTC list serv­er main­tained by the IEEE Prod­uct Safe­ty Engi­neer­ing Soci­ety.

[More infor­ma­tion on the List Serv­er]

[More infor­ma­tion on the Soci­ety]

ESA Manufacturer’s Registration Deadline postponed

This entry is part 1 of 1 in the series Ontario ESA Man­u­fac­tur­ers Reg­istry

If you’ve been fol­low­ing the dis­cus­sions on the EMC/PSTC list serv­er and else­where about the ESA Manufacturer’s reg­istry in Ontario, you may not be aware that ESA has dropped the August 30 dead­line for reg­is­tra­tion. It seems that the Ontario Gov­ern­ment and ESA are review­ing the dead­line fol­low­ing a cab­i­net shake-up at Queen’s Park. There is no word on when or if the dead­line will be rein­stat­ed. Need to know

If you’ve been fol­low­ing the dis­cus­sions on the EMC/PSTC list serv­er and else­where about the ESA Manufacturer’s reg­istry in Ontario, you may not be aware that ESA has dropped the August 30 dead­line for reg­is­tra­tion. It seems that the Ontario Gov­ern­ment and ESA are review­ing the dead­line fol­low­ing a cab­i­net shake-up at Queen’s Park. There is no word on when or if the dead­line will be rein­stat­ed. Need to know more? Come to the PSES Sym­po­sium and be there for ESA’s pre­sen­ta­tion on the Reg­istry!